CN115706880A - Microphone - Google Patents
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- CN115706880A CN115706880A CN202110919048.2A CN202110919048A CN115706880A CN 115706880 A CN115706880 A CN 115706880A CN 202110919048 A CN202110919048 A CN 202110919048A CN 115706880 A CN115706880 A CN 115706880A
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Abstract
The present specification provides a microphone comprising a first acoustic structure, an acousto-electric transducer and a second acoustic structure. The first acoustic structure may comprise a first sound guide tube and a first acoustic cavity. The first acoustic structure has a first resonant frequency. An acoustic-to-electrical converter may be used to convert acoustic signals into electrical signals. The acousto-electric converter has a second resonant frequency. The second acoustic structure may comprise a second sound guide tube and a second acoustic cavity. The second acoustic structure has a third resonant frequency. The third resonant frequency may be different from the first resonant frequency.
Description
Technical Field
The present disclosure relates to the field of acoustic devices, and more particularly, to a microphone.
Background
The filtering and frequency division technology has wide application in signal processing, and is widely applied to the fields of electroacoustic, communication, image coding, echo cancellation, radar sorting and the like as the basis of signal processing technologies such as voice recognition, noise reduction, signal enhancement and the like. Conventional filtering or frequency division methods are techniques that employ hardware circuits or software programs. For example, a full band signal may be collected by a microphone unit, and the signal may be filtered by hardware circuits or software algorithms in a channel division manner. The hardware circuit implements filtering or frequency division, that is, a band-pass filter or a filter bank is designed by using electronic components (for example, analog electronic components, digital electronic languages, etc.), so as to implement filtering or frequency division. The disadvantage is that the higher the performance of the filter, the more complex the circuit design, which is influenced by the characteristics of the electronic components themselves. The filtering or frequency division is realized by using a software algorithm, namely, by using a digital technology, relevant filtering or frequency division programs are executed in a digital signal processing unit (such as a DSP, an FPGA, a CPU, a GPU and the like) according to a filtering or frequency division algorithm which is programmed by software, so that the filtering or frequency division of signals is realized. The method has high requirement on computing resources, and particularly consumes more computing resources and time for a more complex filter algorithm with excellent performance. The digital signal processing is also affected by the sampling frequency, and problems of signal distortion, noise introduction and the like are caused in the sampling and processing processes. Therefore, there is a need for a more efficient signal filtering and/or frequency dividing apparatus and method that simplifies the microphone structure, increases the microphone sound processing efficiency, and increases the frequency response sensitivity of the microphone.
Disclosure of Invention
In order to solve the problems of low filtering and/or frequency dividing efficiency and complex microphone structure, the technical scheme of the specification is realized as follows:
the present specification provides a microphone. The microphone may include a first acoustic structure, an acousto-electric converter, and a second acoustic structure. The first acoustic structure may include a first sound guide tube and a first acoustic cavity. The first acoustic structure has a first resonant frequency. The acousto-electric converter may be for converting an acoustic signal into an electrical signal, and the acousto-electric converter may have a second resonant frequency. The second acoustic structure may include a second sound guide tube and a second acoustic cavity, and the second acoustic structure may have a third resonant frequency. The third resonant frequency may be different from the first resonant frequency.
In some embodiments, an absolute value of a difference of the first resonant frequency or the third resonant frequency and the second resonant frequency may be not less than 100Hz.
In some embodiments, the first resonant frequency may be related to a structural parameter of the first acoustic structure, the second resonant frequency may be related to a structural parameter of the acousto-electric converter, and the third resonant frequency may be related to a structural parameter of the second acoustic structure.
In some embodiments, the structural parameters of the first acoustic structure may include a shape of the first sound guide tube, a size of the first acoustic cavity, an acoustic resistance of the first sound guide tube or the first acoustic cavity, a roughness of an inner surface forming a sidewall of the first sound guide tube, or the like, or a combination thereof. The structural parameters of the second acoustic structure include a shape of the second sound guide tube, a size of the second acoustic cavity, an acoustic resistance of the second sound guide tube or the second acoustic cavity, a roughness of an inner surface forming a sidewall of the second sound guide tube, or the like, or a combination thereof.
In some embodiments, the acoustical resistance may have an acoustical resistance value ranging from 1MKS Rayls to 100MKS Rayls.
In some embodiments, the aperture of the first sound guide tube may be no greater than 2 times its length, and the aperture of the second sound guide tube may be no greater than 2 times its length.
In some embodiments, the roughness of the inner surface of the sidewall forming the first sound guide tube or the second sound guide tube may be not more than 0.8.
In some embodiments, the inner diameter of the first or second acoustic cavity may be no less than its thickness.
In some embodiments, the sensitivity to which the microphone responds at the first resonant frequency may be greater than the sensitivity to which the acousto-electric converter responds at the first resonant frequency. The sensitivity of the microphone response at the third resonant frequency may be greater than the sensitivity of the acousto-electric transducer response at the third resonant frequency.
In some embodiments, the first sound guide tube may be disposed on a cavity wall constituting the first acoustic cavity, and the second sound guide tube may be disposed on a cavity wall constituting the second acoustic cavity.
In some embodiments, the acoustic-to-electric converter may further comprise a first aperture portion through which the first acoustic cavity may be in acoustic communication with the acoustic-to-electric converter.
In some embodiments, the first acoustic cavity may be in acoustic communication with the acousto-electric transducer, and the second acoustic cavity may be in acoustic communication with an exterior of the microphone through the second sound guide tube and may be in acoustic communication with the first acoustic cavity through the first sound guide tube.
In some embodiments, the microphone may further comprise a third acoustic structure, which may comprise a third sound guide tube, a fourth sound guide tube, and a third acoustic cavity. The first acoustic chamber may be in acoustic communication with an exterior of the microphone through the first sound guide tube, and may be in acoustic communication with the third acoustic chamber through the third sound guide tube. The second acoustic cavity may be in acoustic communication with an exterior of the microphone through the second sound pipe, and may be in acoustic communication with the third acoustic cavity through the fourth sound pipe. The third acoustic cavity may be in acoustic communication with the acoustic-to-electrical converter. The third acoustic structure may have a fourth resonant frequency, which may be different from the third resonant frequency and the first resonant frequency.
In some embodiments, the microphone may further include a second acoustic transducer, and the second acoustic transducer may include a second aperture portion, and the second acoustic cavity may be in acoustic communication with an exterior of the microphone through the second sound guide tube and may be in acoustic communication with the second acoustic transducer through the second aperture portion.
Additional features will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following and the accompanying drawings or may be learned by production or operation of the examples. The features of the present invention may be realized and attained by practice or use of various aspects of the methodologies, instrumentalities and combinations particularly pointed out in the following detailed examples.
Drawings
The present description will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate like structures, wherein:
fig. 1 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
fig. 2A is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
fig. 2B is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 3 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 4 is a schematic diagram of a frequency response curve of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 5 is a schematic view of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 6 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 7 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 8 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 9 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 10 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 11 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 12 is a schematic view of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 13 is a schematic view of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 14 is a schematic view of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 15 is a schematic view of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 16 is a schematic diagram of a frequency response curve of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 17 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 18 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 19 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 20 is a schematic view of an exemplary microphone shown in accordance with some embodiments of the present description;
FIG. 21 is a frequency response curve of an exemplary microphone shown in accordance with some embodiments of the present description;
fig. 22 is a frequency response curve of an exemplary microphone shown in accordance with some embodiments of the present description.
Detailed Description
In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only examples or embodiments of the present description, and that for a person skilled in the art, without inventive effort, the present description can also be applied to other similar contexts on the basis of these drawings. It is understood that these exemplary embodiments are given solely to enable those skilled in the relevant art to better understand and implement the present invention, and are not intended to limit the scope of the invention in any way. Unless otherwise apparent from the context, or stated otherwise, like reference numbers in the figures refer to the same structure or operation.
It should be understood that "system", "apparatus", "unit" and/or "component", "assembly", "element" as used herein is a method for distinguishing different assemblies, elements, components, parts or assemblies of different levels. However, other words may be substituted by other expressions if they accomplish the same purpose.
Various terms are used to describe spatial and functional relationships between elements (e.g., between components), including "connected," engaged, "" interface, "and" coupled. Unless explicitly described as "direct," when a relationship between a first and a second element is described in this specification, the relationship includes a direct relationship in which no other intermediate element exists between the first and the second element, and an indirect relationship in which one or more intermediate elements exist (spatially or functionally) between the first and the second element. In contrast, when an element is referred to as being "directly" connected, joined, interfaced, or coupled to another element, there are no intervening elements present. In addition, the spatial and functional relationships between elements may be implemented in various ways. For example, the mechanical connection between two elements may include a welded connection, a keyed connection, a pinned connection, an interference fit connection, or the like, or any combination thereof. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between," "and," "adjacent," and "directly adjacent," etc.).
It should be understood that the terms "first," "second," "third," and the like as used herein may be used to describe various elements. These are used only to distinguish one element from another and are not intended to limit the scope of the elements. For example, a first element can also be referred to as a second element, and similarly, a second element can also be referred to as a first element.
As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" are intended to cover only the explicitly identified steps or elements as not constituting an exclusive list and that the method or apparatus may comprise further steps or elements. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions for other terms will be given in the following description. In the following, without loss of generality, the description of "microphone" or "microphone" will be employed in describing the present invention with respect to filtering/dividing related techniques. The description is merely one form of conductive application and it will be apparent to those skilled in the art that the "microphone" or "microphone" may be replaced by other similar words such as "hydrophone", "transducer", "acousto-optic modulator" or "acousto-electric transducer", etc. It will be apparent to persons skilled in the relevant art that various modifications and changes in form and detail can be made in the specific forms and steps of implementing the microphone without departing from the basic principles of the microphone. However, such modifications and changes are still within the scope of the present specification.
The present specification provides a microphone. The microphone may comprise at least one acousto-electric transducer and an acoustic structure. At least one acousto-electric converter may be used to convert the acoustic signal into an electrical signal. The acoustic structure includes a sound guide tube and an acoustic cavity. The acoustic cavity is in acoustic communication with the acousto-electric transducer and is in acoustic communication with the exterior of the microphone through the sound guide tube. The sound guide tube and the acoustic cavity of the acoustic structure may constitute a filter having a function of adjusting frequency components of sound. According to the scheme, the sound signal is filtered and/or sub-band frequency division is carried out by using the structural characteristics of the acoustic structure, a large number of complex circuits are not needed for realizing filtering, and the difficulty of circuit design is reduced. The filtering characteristics of an acoustic structure are determined by the physical characteristics of its structure, and the process of filtering occurs in real time.
In some embodiments, the acoustic structure may "amplify" the sound at its corresponding resonant frequency. The resonant frequency of the acoustic structure can be adjusted by changing the structural parameters of the acoustic structure. The structural parameters of the acoustic structure may include the shape of the sound guide tube, the dimensions of the acoustic cavity, the acoustic resistance of the sound guide tube or the acoustic cavity, the roughness of the inner surface of the side wall of the sound guide tube, the thickness of the sound absorbing material in the sound guide tube, etc. or combinations thereof.
In some embodiments, by arranging a plurality of acoustic structures having different resonant frequencies in parallel, in series, or in combination thereof, frequency components corresponding to different resonant frequencies in the sound signal can be respectively screened out, so that sub-band frequency division of the sound signal can be realized. In this case, the frequency response of the microphone may be viewed as a flatter frequency response curve (e.g., frequency response curve 2210 shown in FIG. 22) with a high signal-to-noise ratio resulting from the fusion of the frequency responses of the different acoustic structures. On one hand, the microphone provided in the embodiments of the present specification can perform sub-band frequency division processing on a full-band signal through its own structure without using a hardware circuit (for example, a filter circuit) or a software algorithm, so that problems of complex hardware circuit design, high occupation of computational resources by the software algorithm, signal distortion, and noise introduction are avoided, and further, the complexity and the production cost of the microphone are reduced. On the other hand, the microphone provided by the embodiment of the specification can output a frequency response curve with high signal-to-noise ratio and flatness, and the signal quality of the microphone is improved. In addition, by arranging different acoustic structures, resonance peaks in different frequency ranges can be added in the microphone system, the sensitivity of the microphone near a plurality of resonance peaks is improved, and the sensitivity of the microphone in the whole broadband is further improved.
Fig. 1 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 1, the microphone 100 may include an acoustic structure 110, at least one acousto-electric converter 120, a sampler 130 and a signal processor 140.
In some embodiments, the microphone 100 may include any sound signal processing device that converts sound signals into electrical signals, such as a microphone, a hydrophone, an acousto-optic modulator, etc., or other acousto-electrical conversion device. In some embodiments, distinguished by the principle of transduction, the microphone 110 may include a moving coil microphone, a ribbon microphone, a condenser microphone, a piezoelectric microphone, an electret microphone, an electromagnetic microphone, a carbon particle microphone, or the like, or any combination thereof. In some embodiments, the microphone 110 may comprise a bone conduction microphone, an air conduction microphone, the like, or combinations thereof, differentiated by way of sound collection. In some embodiments, the microphone 110 may include an electret microphone, a silicon microphone, or the like, as distinguished by the manufacturing process. In some embodiments, the microphone 100 may be disposed on a mobile device (e.g., a cell phone, a voice pen, etc.), a tablet computer, a laptop computer, a vehicle-mounted device, a monitoring device, a medical device, a piece of athletic equipment, a toy, a wearable device (e.g., a headset, a helmet, glasses, a necklace, etc.), etc., that has a sound pickup function.
The acoustic structure 110 may transmit an external sound signal to the at least one acousto-electric transducer 120. The acoustic structure 110 may perform certain conditioning on the sound signal as it passes through the acoustic structure 110 (e.g., filtering, changing the bandwidth of the sound signal, amplifying the sound signal for particular frequencies, etc.). In some embodiments, the acoustic structure 110 may include a sound guide tube and an acoustic cavity. The acoustic cavity is in acoustic communication with the acousto-electric transducer 120 for conveying acoustic signals conditioned by the acoustic structure 110 to the acousto-electric transducer 120. The acoustic cavity may be in acoustic communication with the environment outside the microphone 100 through a sound guide tube for receiving sound signals. The sound signal may be from any sound source capable of generating an audio signal. The sound source may be a living organism (e.g., a user of the microphone 100), a non-living organism (e.g., a CD player, a television, a stereo, etc.), and the like or combinations thereof. In some embodiments, the sound signal may comprise ambient sound.
In some embodiments, the acoustic structure 110 has a first resonant frequency, which indicates that a frequency component of the acoustic signal at the first resonant frequency will resonate, thereby increasing the volume of sound delivered to the acousto-electric converter 120. Thus, the acoustic structure 110 may be arranged such that the frequency response curve of the microphone 100 generates a resonance peak at the first resonance frequency, such that the sensitivity of the microphone 100 may be increased within a certain frequency band including the first resonance frequency. Reference may be made to fig. 2A-22 and associated description regarding the effect of the acoustic structure 110 on the frequency response curve of the microphone 100.
In some embodiments, the number of acoustic structures 110 in the microphone 100 may be set according to actual needs. For example, the microphone 100 may include a plurality (e.g., 2, 3, 5, 6-24, etc.) of acoustic structures 110. In some embodiments, the plurality of acoustic structures 110 in the microphone 100 may have different frequency responses, e.g., the plurality of acoustic structures 110 in the microphone 100 may have different resonant frequencies and/or frequency bandwidths. The frequency bandwidth may refer to the frequency range between the 3dB points of the frequency response curve. In some embodiments, the sound signal may be frequency divided after being processed by the plurality of acoustic structures 100 to generate a plurality of sub-band sound signals (e.g., sub-band sound signal 1111, sub-band sound signal 1112, \8230;, sub-band sound signal 111 n) having different frequency band ranges. The subband sound signal refers to a signal having a frequency bandwidth smaller than that of the original sound signal. The frequency band of the sub-band acoustic signal may be within the frequency band of the acoustic signal. For example, the sound signal may have a frequency band in the range of 100Hz-20000Hz, an acoustic structure 110 may be arranged to filter the sound signal to generate a sub-band sound signal having a frequency band in the range of 100Hz-200Hz. As another example, 11 acoustic structures 110 may be provided and the sound signal divided to generate 11 sub-band sound signals having frequency bands in the range of 500Hz-700Hz, 700Hz-1000Hz, 1000Hz-1300Hz, 1300Hz-1700Hz, 1700Hz-2200Hz, 2200Hz-3000Hz, 3000Hz-3800Hz, 3800Hz-4700Hz, 4700Hz-5700Hz, 5700Hz-7000Hz, 7000Hz-12000Hz. Also for example, 16 acoustic structures 110 may be provided and the sound signal divided to generate 16 sub-band sound signals, which may have frequency bands ranging from 500Hz-640Hz, 640Hz-780Hz, 780Hz-930Hz, 940Hz-1100Hz, 1100Hz-1300Hz, 1300Hz-1500Hz, 1500Hz-1750Hz, 1750Hz-1900Hz, 1900Hz-2350Hz, 2350Hz-2700Hz, 2700Hz-3200Hz, 3200Hz-3800Hz, 3800Hz-4500Hz, 4500Hz-5500Hz, 5500Hz-6600Hz, 6600Hz-8000Hz. For another example, 24 acoustic structures 110 may be provided to divide the sound signal to generate 24 sub-band sound signals, which may have frequency bands ranging from 20Hz-120Hz, 120Hz-210Hz, 210Hz-320Hz, 320Hz-410Hz, 410Hz-500Hz, 500Hz-640Hz, 640Hz-780Hz, 780Hz-930Hz, 940Hz-1100Hz, 1100Hz-1300Hz, 1300Hz-1500Hz, 1500Hz-1750, 1750Hz-1900Hz, 1900Hz-2350, 2350Hz-2700Hz, 2700Hz-3200Hz, 3200Hz-3800Hz, 3800Hz-4500Hz, 4500Hz-5500Hz, 5500Hz-6600Hz, 6600Hz-7900Hz, 7900Hz-9600Hz, 9600Hz-12100Hz, 12100-16000 Hz. The acoustic structure is used for filtering and frequency division, real-time filtering and/or frequency division can be carried out on the sound signals, introduction of noise in the sound signal processing process by subsequent hardware is reduced, and signal distortion is avoided.
In some embodiments, the plurality of acoustic structures 110 in the microphone 100 may be arranged in parallel, in series, or a combination thereof. Details regarding the arrangement of the plurality of acoustic structures can be found in fig. 17-20 and their associated description.
The acoustic structure 110 may be coupled to an acousto-electric converter 120 for transmitting the sound signal conditioned by the acoustic structure 110 to the acousto-electric converter 120 for conversion into an electrical signal. In some embodiments, the acousto-electrical converter 120 may comprise a capacitive acousto-electrical converter, a piezoelectric acousto-electrical converter, or the like, or combinations thereof. In some embodiments, vibration of the acoustic signal (e.g., air vibration, solid vibration, liquid vibration, magnetic vibration, electric vibration, etc.) may cause a change in one or more parameters of the acousto-electric transducer 120 (e.g., capacitance, charge, acceleration, light intensity, frequency response, etc., or combinations thereof) that may be electrically detected and output an electrical signal corresponding to the vibration. For example, a piezoelectric acousto-electric transducer may be an element that converts a change in a measured non-electrical quantity (e.g., pressure, displacement, etc.) into a change in voltage. For example, the piezoelectric electroacoustic transducer may include a cantilever structure (or a diaphragm structure), and the cantilever structure may be deformed by an acoustic signal received by the cantilever structure, and an inverse piezoelectric effect caused by the deformed cantilever structure may generate an electrical signal. For another example, a capacitive acoustic-electric transducer may be an element that converts a change in a measured non-electrical quantity (e.g., displacement, pressure, light intensity, acceleration, etc.) into a change in capacitance. For example, the capacitive acoustic-to-electrical converter may include a first cantilever beam structure and a second cantilever beam structure that may deform to different degrees under vibration, thereby causing a change in a separation distance between the first cantilever beam structure and the second cantilever beam structure. The first cantilever beam structure and the second cantilever beam structure can convert the change of the distance between the first cantilever beam structure and the second cantilever beam structure into the change of capacitance, so that the conversion from a vibration signal to an electric signal is realized. In some embodiments, different acousto-electric converters 120 may have the same or different frequency responses. For example, the same sound signal may be detected by the acousto-electric converters 120 having different frequency responses, and sub-band electric signals having different resonance frequencies may be generated by different acousto-electric converters 120.
In some embodiments, the number of the acoustic-electric converters 120 may be one or more, for example, the acoustic-electric converters 120 may include an acoustic-electric converter 121, an acoustic-electric converter 122, \ 8230, and an acoustic-electric converter 12n. In some embodiments, one or more of the acousto-electrical converters 120 may communicate with the acoustic structure 110 in a variety of ways. For example, multiple acoustic structures 110 in the microphone 100 may be connected to the same acousto-electric transducer 120. As another example, each of the plurality of acoustic structures 110 may be coupled to one acoustic-to-electrical converter 120.
In some embodiments, one or more of the acousto-electrical converters 120 may be used to convert the acoustic signals conveyed by the acoustic structure 110 into electrical signals. For example, the acousto-electric converter 120 may convert the filtered sound signal of the acoustic structure 110 into a corresponding electrical signal. For another example, a plurality of the acoustic-to-electric converters 120 may convert the sub-band acoustic signals divided by the plurality of acoustic structures 110 into a corresponding plurality of sub-band electrical signals, respectively. For example only, the acousto-electric converter 120 may convert the sub-band acoustic signal 1111, the sub-band acoustic signal 1112, \8230, the sub-band acoustic signal 111n into the sub-band electric signal 1211, the sub-band electric signal 1212, \8230, the sub-band electric signal 121n, respectively.
The acoustic-electric converter 120 may transmit the generated sub-band electric signal (or electric signal) to the sampler 130. In some embodiments, one or more sub-band electrical signals may be separately transmitted over different parallel line media. In some embodiments, the plurality of sub-band electrical signals may also be output in a specific format according to a specific protocol rule by sharing a line medium. In some embodiments, the specific protocol rules may include, but are not limited to, one or more of direct transmission, amplitude modulation, frequency modulation, and the like. In some embodiments, the line medium may include, but is not limited to, one or more of coaxial cable, communications cable, flex cable, spiral cable, non-metallic sheathed cable, multi-core cable, twisted pair cable, ribbon cable, shielded cable, telecommunications cable, twinax cable, parallel twin conductor, twisted pair, optical fiber, infrared, electromagnetic waves, acoustic waves, and the like. In some embodiments, the particular format may include, but is not limited to, one or more of CD, WAVE, AIFF, MPEG-1, MPEG-2, MPEG-3, MPEG-4, MIDI, WMA, realAudio, VQF, AMR, APE, FLAC, AAC, and the like. In some embodiments, the transport protocols may include, but are not limited to, one or more of AES3, EBU, ADAT, I2S, TDM, MIDI, cobraNet, ethernet AVB, dante, ITU-T G.728, ITU-T G.711, ITU-T G.722, ITU-T G.722.1Annex C, AAC-LD, and the like.
The sampler 130 may be in communication with the acousto-electric converter 120 for receiving the one or more sub-band electrical signals generated by the acousto-electric converter 120 and sampling the one or more sub-band electrical signals to generate corresponding digital signals.
In some embodiments, sampler 130 may include one or more samplers (e.g., sampler 131, sampler 132, \8230; sampler 13 n). Each sampler may sample each sub-band signal. For example, sampler 131 may sample sub-charged signal 1211 to generate digital signal 1311. As another example, sampler 132 may sample the sub-band signal 1212 to generate a digital signal 1312. As another example, sampler 13n may sample the sub-band signal 121n to generate a digital signal 131n.
In some embodiments, sampler 130 may sample the sub-charged signal using a band-pass sampling technique. For example, the sampling frequency of the sampler 130 may be configured according to the frequency bandwidth (3 dB) of the sub-band electric signal. In some embodiments, the sampler 130 may sample the sub-band electrical signals with a sampling frequency that is no less than twice the highest frequency of the sub-band electrical signals. In some embodiments, the sampler 130 may sample the sub-band electrical signals with a sampling frequency that is no less than twice the highest frequency in the sub-band electrical signals and no greater than four times the highest frequency in the sub-band electrical signals. Compared with the conventional sampling method (e.g., bandwidth sampling technique, low-pass sampling technique, etc.), the sampling method using the band-pass sampling technique can use a relatively low sampling frequency for sampling, so as to reduce the difficulty and cost of the sampling process.
In some embodiments, the magnitude of the sampling frequency of the sampler 130 may affect the cutoff frequency of the sampling by the sampler 130. In some embodiments, the larger the sampling frequency, the higher the cut-off frequency, and the larger the range of the sampling frequency band, and the larger the sampling frequency, the lower the frequency resolution corresponding to the larger sampling frequency when the signal processor 140 processes the digital signal generated by the sampler 130. Thus, for sub-band electrical signals located in different frequency ranges, the sampler 130 may sample using different sampling frequencies. For example, for sub-band electrical signals located in a low frequency range (e.g., sub-band electrical signals having a frequency less than a first frequency threshold), the sampler 130 may use a lower sampling frequency, thereby making the cut-off frequency of the sampling lower. For another example, for sub-band electrical signals having a frequency range at a mid-to-high frequency (e.g., sub-band electrical signals having a frequency greater than the second frequency threshold and less than the third frequency threshold), the sampler 130 may use a higher sample frequency, such that the cut-off frequency of the sampling is relatively higher. As another example, the sampling cutoff frequency of the sampler 130 may be 0Hz-500Hz above the 3dB bandwidth frequency point frequency of the resonance frequency of the sub-band.
The sampler 130 may transmit the generated one or more digital signals to the signal processor 140. The transmission of one or more digital signals may be transmitted separately over different parallel line media. In some embodiments, one or more digital signals may also share a line medium for transmission in a particular format according to particular protocol rules. For the transmission of digital signals reference can be made to the transmission of subband electrical signals.
The signal processor 140 may receive and process data from other components of the microphone 100. For example, the signal processor 140 may process the digital signal transmitted from the sampler 130. In some embodiments, the signal processor 140 may process each sub-band electrical signal transmitted from the sampler 130 individually to generate a corresponding digital signal. For example, each sub-band electrical signal may be processed by the signal processor 140 for different sub-band electrical signals (e.g., sub-band electrical signals processed by different acoustic structures, acousto-electric converters, etc.) that may have different phases, corresponding frequencies, etc. In some embodiments, the signal processor 140 may obtain a plurality of sub-band electrical signals from the sampler 130 and process (e.g., fuse) the plurality of sub-band electrical signals to generate a wideband signal for the microphone 100.
In some embodiments, the signal processor 140 may also include one or more of an equalizer, a dynamic range controller, a phase processor, and the like. In some embodiments, the equalizer may be configured to gain and/or attenuate the digital signal output by the sampler 130 according to a particular frequency band (e.g., a frequency band corresponding to the digital signal). The step of gaining the digital signal refers to increasing the signal amplification amount; attenuating a digital signal refers to reducing the amount of signal amplification. In some embodiments, the dynamic range controller may be configured to compress and/or amplify the digital signal. Compressing and/or amplifying the sub-band-divided electrical signal refers to reducing and/or increasing the ratio between the input signal and the output signal in the microphone 100. In some embodiments, the phase processor may be configured to adjust the phase of the digital signal. In some embodiments, the signal processor 140 may be located inside the microphone 100. For example, the signal processor 140 may be located in an acoustic cavity formed separately from the housing structure of the microphone 100. In some embodiments, the signal processor 140 may also be located in other electronic devices, for example, one or any combination of a headset, a mobile device, a tablet computer, a notebook computer, and the like. In some embodiments, the mobile device may include, but is not limited to, a cell phone, a smart home device, a smart mobile device, and the like, or any combination thereof. In some embodiments, the smart home device may include a control device of a smart appliance, a smart monitoring device, a smart television, a smart camera, or the like, or any combination thereof. In some embodiments, the smart mobile device may include a smart phone, a Personal Digital Assistant (PDA), a gaming device, a navigation device, a POS device, or the like, or any combination thereof.
The description of the microphone 100 above is for illustrative purposes only and is not intended to limit the scope of the present description. Various changes and modifications will occur to those skilled in the art based on the description herein. For example, the sampler 130 and the signal processor 140 may be integrated in one component (e.g., an Application Specific Integrated Circuit (ASIC)). Such variations and modifications are intended to be within the scope of the present disclosure.
Fig. 2A is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 2A, the microphone 200 may include a housing 210, at least one acousto-electric converter 220 and an acoustic structure 230.
The housing 210 may be configured to house one or more components of the microphone 200 (e.g., at least one acousto-electric transducer 220, at least a portion of an acoustic structure 230, etc.). In some embodiments, the housing 210 may be a regular structure such as a rectangular parallelepiped, a cylinder, a prism, a truncated cone, or other irregular structure. In some embodiments, housing 210 is a hollow structure that may form one or more acoustic cavities, such as acoustic cavity 231 and acoustic cavity 240. The acoustic cavity 240 may house the acoustic-electric converter 220 and the application specific integrated circuit 250. The acoustic cavity 231 may house or be at least part of the acoustic structure 230. In some embodiments, the enclosure 210 may include only one acoustic cavity. As an example, fig. 2B is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. The housing 210 of the microphone 205 may form an acoustic cavity 240. One or more components of the microphone 205, such as the acousto-electric converter 220, the application specific integrated circuit 250, and at least a portion of the acoustic structure 230 (e.g., the acoustic cavity 231) may be located in the acoustic cavity 231. In this case, the acoustic cavity 240 formed by the casing 210 may coincide with the acoustic cavity 231 of the acoustic structure 230. The acoustic structure 230 may be in direct acoustic communication with the acousto-electric transducer 220. The acoustic structure 230 and the acousto-electric transducer 220 are in direct acoustic communication it being understood that the acousto-electric transducer 220 may include a "front cavity" and a "back cavity", where acoustic signals in the "front cavity" or the "back cavity" may cause a change in one or more parameters of the acousto-electric transducer 220. In the microphone 200 shown in fig. 2A, the acoustic signal passes through the acoustic structure 230 (e.g., the sound guide tube 232 and the acoustic cavity 231) and then through the aperture portion 221 of the acousto-electric converter 220 to the "back cavity" of the acousto-electric converter 220, causing a change in one or more parameters of the acousto-electric converter 220. In the microphone 205 shown in fig. 2B, the acoustic cavity 240 formed by the casing 210 coincides with the acoustic cavity 231 of the acoustic structure 230, and it can be considered that the "front cavity" of the acoustic-electric converter 220 coincides with the acoustic cavity 231 of the acoustic structure, and the sound signal directly causes a change in one or more parameters of the acoustic-electric converter 220 after passing through the acoustic structure 230. For convenience of description, the present specification mainly takes as an example that the acoustic cavity 231 and the acoustic cavity 240 are not overlapped (as shown in fig. 2A), and the at least one acoustic-electric converter 220 is disposed in the acoustic cavity 240, and the overlapping condition of the acoustic cavity 231 and the acoustic cavity 240 may be the same or similar.
In some embodiments, the material of the housing 210 may include, but is not limited to, one or more of metal, alloy material, polymer material (e.g., acrylonitrile butadiene styrene, polyvinyl chloride, polycarbonate, polypropylene, etc.), and the like.
In some embodiments, at least one acousto-electric converter 220 may be used to convert acoustic signals into electrical signals. The at least one acousto-electric converter 220 may include one or more aperture sections 221. The acoustic structure 230 may communicate with at least one acousto-electric transducer 220 through one or more aperture portions 221 of the acousto-electric transducer 220 and pass the acoustic signal conditioned by the acoustic structure 230 to the acousto-electric transducer 220. For example, an external sound signal picked up by the microphone 200 may enter the cavity (if any) of the acoustic transducer 220 through the aperture portion 221 after being conditioned (e.g., filtered, divided, amplified, etc.) by the acoustic structure 230. The acoustic-to-electrical converter 220 may pick up the acoustic signal and convert it to an electrical signal.
In some embodiments, the acoustic structure 230 may include an acoustic cavity 231 and a sound guide tube 232. The acoustic structure 230 may communicate with the exterior of the microphone 200 through a sound guide tube 232. In some embodiments, the housing 210 may include a plurality of sidewalls to form a space within the housing. The sound guide tube 232 may be located on the first sidewall 211 of the housing 210 for forming the acoustic cavity 231. Specifically, a first end of the sound guide tube 232 (e.g., an end near the acoustic cavity 231) may be located on the first sidewall 211 of the housing 210, and a second end of the sound guide tube 232 (e.g., an end relatively far from the acoustic cavity 231) may be located away from the first sidewall 211 and outside the housing 210. An external sound signal may enter the sound guide tube 232 from the second end of the sound guide tube 232 and pass from the first end of the sound guide tube 232 to the acoustic cavity 231. In some embodiments, the sound guide tube 232 of the acoustic structure 230 may also be disposed at other suitable locations, and reference may be made to fig. 5-9 and their associated description regarding the placement of the sound guide tube.
In some embodiments, the acoustic structure 230 may have a first resonant frequency, i.e., a component of the acoustic signal at the first resonant frequency may resonate within the acoustic structure 230. In some embodiments, the first resonant frequency is related to a structural parameter of the acoustic structure 230. The structural parameters of the acoustic structure 230 may include the shape of the sound guide tube 232, the size of the acoustic cavity 231, and the acoustic resistance of the sound guide tube 232 or the acoustic cavity 231, the roughness of the inner surface of the side wall of the sound guide tube 232, the thickness of the sound absorbing material (e.g., fibrous material, foam material, etc.) in the sound guide tube, the stiffness of the inner wall of the acoustic cavity, etc., or combinations thereof. In some embodiments, by setting the structural parameters of the acoustic structure 230, the sound signal conditioned by the acoustic structure 230 can be made to have a resonance peak at the first resonance frequency after being converted into an electrical signal.
The shape of the sound guide tube 232 may include regular and/or irregular shapes such as rectangular parallelepiped, cylinder, polygonal prism, etc. In some embodiments, the sound guide tube 232 may be formed surrounded by one or more sidewalls. The sidewall 233 of the sound guide tube 232 may have a regular and/or irregular structure such as a rectangular parallelepiped, a cylinder, etc. In some embodiments, as shown in fig. 3, the length of the sidewall 233 of the sound guide tube 232 (e.g., the sum of the length of the sidewall 233 in the X-axis direction and the aperture of the sound guide tube 232 in fig. 2A) may be the same as the length of the housing 210 in the X-axis direction. In some embodiments, the length of the sidewall 233 of the sound guide tube 232 may be different from the length of the housing 210. For example, fig. 3 is a schematic view of an exemplary microphone according to some embodiments of the present disclosure, as shown in fig. 3, a first end of the sound guide tube 232 is located on the first sidewall 211 of the housing 210, and a second end of the sound guide tube 232 is located away from the first sidewall 211 and outside the housing 210. The length of the hole sidewall 233 of the sound guide tube 232 in the X-axis direction is smaller than the length of the housing 210 in the X-axis direction.
The structural parameters such as the aperture and length of the sound guide tube 232 and the structural parameters such as the inner diameter, length and thickness of the acoustic cavity 231 may be set as required (e.g., a target resonance frequency, a target frequency bandwidth, etc.). The length of the sound guide tube refers to the total length of the sound guide tube 232 in the central axis direction of the sound guide tube (e.g., the Y-axis direction in fig. 2A). In some embodiments, the length of the sound guide 232 may be the equivalent length of the sound guide, i.e., the length of the sound guide in the direction of the central axis plus the product of the diameter of the sound guide and the length correction factor. As shown in fig. 2A, the length of the acoustic cavity 231 refers to the dimension of the acoustic cavity 231 in the X-axis direction. The thickness of the acoustic cavity 231 refers to the dimension of the acoustic cavity 231 in the Y-axis direction. In some embodiments, the aperture of the sound guide tube 232 may be no greater than 2 times the length of the sound guide tube 232. In some embodiments, the aperture of the sound guide tube 232 may be no greater than 1.5 times the length of the sound guide tube 232. For example, when the cross-section of the sound guide tube 232 (e.g., a cross-section perpendicular to the center axis of the sound guide tube (e.g., a cross-section parallel to the XZ plane) is circular, the aperture of the sound guide tube 232 may be in the range of 0.5 mm to 10 mm, and the length of the sound guide tube 232 may be in the range of 1 mm to 8 mm. Yet, for example, when the cross-section of the sound guide tube 232 is circular, the aperture of the sound guide tube 232 may be in the range of 1 mm to 4 mm, and the length of the sound guide tube 232 may be in the range of 1 mm to 10 mm. In some embodiments, the inner diameter of the acoustic cavity 231 may be not less than the thickness of the acoustic cavity 231. In some embodiments, the inner diameter of the acoustic cavity 231 may be not less than 0.8 times the thickness of the acoustic cavity 231. For example, when the cross-section of the acoustic cavity 231 perpendicular to its length (e.g., a cross-section parallel to the YZ plane) is circular, the inner diameter of the acoustic cavity 231 may be in the range of 1 mm to 20 mm, the thickness of the acoustic cavity 231 may be in the range of 1 mm to 20 mm, and the inner diameter of the acoustic cavity 231 may be in some embodiments, the cross-231 may be in the range of 1 mm to 15 mm.
The cross-sectional shape of the acoustic cavity 231 and/or the sound guide tube 232 is not limited to the circular shape, and may be other shapes, such as a rectangle, an ellipse, a pentagon, and the like. In some embodiments, when the cross-sectional shape of the acoustic cavity 231 and/or the sound guide tube 232 is other shapes (non-circular), the inner diameter of the acoustic cavity 231 and/or the aperture (or thickness, length) of the sound guide tube 232 may be equivalent to an equivalent inner diameter or an equivalent aperture. Taking an equivalent inner diameter as an example, an acoustic cavity 231 having another cross-sectional shape may be represented by an inner diameter of an acoustic cavity and/or a sound guide tube having a circular cross-sectional shape equal to the volume thereof. For example, when the cross-section of the acoustic cavity 231 is square, the equivalent inner diameter of the acoustic cavity 231 may be in the range of 1 mm to 6 mm, and the thickness of the acoustic cavity 231 may be in the range of 1 mm to 4 mm. For another example, when the cross-section of the acoustic cavity 231 is square, the equivalent inner diameter of the acoustic cavity 231 may be in a range of 1 mm to 5 mm, and the thickness of the acoustic cavity 231 may be in a range of 1 mm to 3 mm.
In some embodiments, the sidewall 233 of the sound guide tube 232 may be made of one or more materials. The material of the sidewalls 233 may include, but is not limited to, one or more of a semiconductor material, a metal alloy, an organic material, and the like. In some embodiments, the semiconductor material may include, but is not limited to, silicon dioxide, silicon nitride, silicon carbide, and the like. In some embodiments, the metallic material may include, but is not limited to, copper, aluminum, chromium, titanium, gold, and the like. In some embodiments, the metal alloy may include, but is not limited to, copper aluminum alloys, copper gold alloys, titanium alloys, aluminum alloys, and the like. In some embodiments, the organic material may include, but is not limited to, polyimide (PI), parylene, polydimethylsiloxane (PDMS), silicone gel, silica gel, and the like.
The description of microphone 200 above is for illustrative purposes only and is not intended to limit the scope of the present description. Various changes and modifications may be made by one of ordinary skill in the art in light of the description herein. Such variations and modifications are intended to be within the scope of the present disclosure.
Fig. 4 is a schematic illustration of a frequency response curve of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 4, frequency response curve 410 is a frequency response curve of an acoustic-to-electrical converter (e.g., acoustic-to-electrical converter 220), and frequency response curve 420 is a frequency response curve of an acoustic structure (e.g., acoustic structure 230). When the frequency response curve 410 is at the frequency f 0 Has a resonance peak at the frequency f 0 May be referred to as the resonant frequency of the acousto-electric transducer (which may also be referred to as the second resonant frequency). In some embodiments, the resonant frequency of the acousto-electric converter is related to a structural parameter of the acousto-electric converter. The structural parameters of the acousto-electric transducers may include the size, mass, type, arrangement, etc. of the acousto-electric transducers (e.g., acousto-electric transducers 220).
At frequency f of frequency response curve 420 1 Where the acoustic structure resonates with the received sound signal such that the sound signal contains a frequency f 1 Amplifying the frequency band signal of (1), the frequency f of the resonance 1 Which may be referred to as the resonant frequency of the acoustic structure (which may also be referred to as the first resonant frequency). The resonant frequency of the acoustic structure can be expressed as formula (1):
wherein f denotes the resonance frequency of the acoustic structure, c 0 Denotes the speed of sound in air, S denotes the cross-sectional area of the sound guide tube, l denotes the length of the sound guide tube, and V denotes the volume of the acoustic chamber.
As can be seen from equation (1), the resonant frequency of the acoustic structure is related to the cross-sectional area of the sound guide tube, the length of the sound guide tube, and the volume of the acoustic cavity in the acoustic structure, and specifically, the resonant frequency of the acoustic structure is positively related to the cross-sectional area of the sound guide tube and negatively related to the length of the sound guide tube and/or the volume of the acoustic cavity. The resonant frequency of the acoustic structure may be adjusted by setting structural parameters of the acoustic structure, such as the shape of the sound guide tube, the size of the sound guide tube, the volume of the acoustic cavity, and the like, or combinations thereof. For example, in the case that the length of the sound guide tube and the volume of the acoustic cavity are not changed, the cross-sectional area of the sound guide tube can be reduced by reducing the aperture of the sound guide tube, so as to reduce the resonance frequency of the acoustic structure. For another example, in the case that the cross-sectional area of the sound guide tube and the length of the sound guide tube are not changed, the resonance frequency of the acoustic structure can be increased by reducing the volume of the acoustic cavity. For another example, the resonance frequency of the acoustic structure can be reduced by increasing the volume of the acoustic cavity under the condition that the cross-sectional area and the length of the sound guide tube are not changed.
In some embodiments, in order to improve the response of the microphone to sound signals in the lower frequency range, the structural parameters of the acoustic structure may be set such that the first resonance frequency f 1 Less than the second resonance frequency f 0 . In some embodiments, in order to keep the frequency response of the microphone flat over a larger frequency range, the structural parameters of the acoustic structure may be set such that the first resonance frequency f 1 And a second resonance frequency f 0 Is not less than the frequency threshold. The frequency threshold may be determined according to actual needs, for example, the frequency threshold may be set to 5Hz, 10Hz, 100Hz, 1000Hz, and the like. In some embodiments, the first resonant frequency f 1 May be greater than or equal to the second resonant frequency f 0 Thereby increasing the sensitivity of the frequency response of the microphone at different frequency ranges.
In some embodiments, the sound signal, after conditioning by the acoustic structure, contains a first resonant frequency f 1 Is amplified such that the microphone as a whole is at a first frequency f 1 The response ofThe sensitivity is greater than the sensitivity of the acousto-electric transducer response at the first frequency, thereby increasing the sensitivity and Q-value of the microphone near the first resonant frequency (e.g., the sensitivity of the microphone at frequency f) 1 The lift of (A) can be represented by (delta) V in FIG. 4 1 Representation). In some embodiments, by providing acoustic structures in the microphone, the sensitivity of the microphone may be increased by 5-40 dBV over different frequency ranges compared to the sensitivity of the acousto-electric transducer. In some embodiments, by placing acoustic structures in the microphone, the sensitivity of the microphone can be increased by 10-20 dBV over different frequency bands. In some embodiments, the amount of increase in the sensitivity of the microphone in different frequency ranges may be different. For example, the higher the frequency, the greater the amount of increase in the sensitivity of the microphone in the corresponding frequency band. In some embodiments, the amount of increase in the sensitivity of the microphone may be represented by a change in the slope of the sensitivity over a range of frequencies. In some embodiments, the range of slope variations of the sensitivity of the microphone over different frequency ranges may be between 0.0005dBV/Hz and 0.005dBV/Hz. In some embodiments, the range of slope variations of the sensitivity of the microphone over different frequency ranges may be between 0.001dBV/Hz and 0.003dBV/Hz. In some embodiments, the range of slope variations of the sensitivity of the microphone over different frequency ranges may be between 0.002dBV/Hz and 0.004dBV/Hz.
In some embodiments, the bandwidth of the frequency response curve of the acoustic structure at the first resonant frequency may be represented by equation (2):
where Δ f represents the bandwidth of the acoustic structure frequency response, f represents the resonant frequency, R 'of the acoustic structure' a Denotes the total acoustic resistance of the sound guide tube (including the acoustic resistance and the radiated acoustic resistance of the sound guide tube), M' a Denotes the total acoustic mass of the sound guide (including the sound guide acoustic mass and the radiated acoustic mass), W r Representing the resonant circular frequency of the acoustic structure and f representing the resonant frequency of the acoustic structure.
As can be seen from equation (2), in the case where the resonant frequency of the acoustic structure is determined, the bandwidth of the acoustic structure can be adjusted by adjusting the acoustic resistance of the sound guide tube. In some embodiments, a sound resistance structure may be disposed in the microphone, and the sound resistance value of the sound resistance structure is adjusted by adjusting the aperture, thickness, aperture ratio, and the like of the sound resistance structure, so as to adjust the bandwidth of the sound structure. Details regarding the acoustical resistance structure can be found in fig. 10-16 and their associated description.
In some embodiments, the acoustic impedance of the sound guide tube may be adjusted by adjusting the roughness of the inner surface of the side wall of the sound guide tube, thereby adjusting the frequency bandwidth of the frequency response curve of the acoustic structure. In some embodiments, the inner surface roughness of the sidewall of the sound guide tube may be less than or equal to 0.8. In some embodiments, the inner surface roughness of the sidewall of the sound guide tube may be less than or equal to 0.4. Taking the frequency bandwidth of 3dB of the frequency response curve of the microphone as an example, the frequency bandwidth of 3dB of the frequency response curve of the microphone can be 100Hz to 1500Hz by adjusting the structural parameters of the acoustic structure. In some embodiments, the 3dB bandwidth of the microphone at different resonant frequencies can be increased by different amounts by adjusting the roughness of the inner surface of the side wall of the sound guide tube for different acoustic structures. For example, by adjusting the roughness of the inner surface of the side wall of the sound guide tube corresponding to different acoustic structures, the higher the resonance frequency of the acoustic structure, the greater the amount of increase in the 3dB frequency bandwidth of the microphone at its corresponding resonance frequency. In some embodiments, the amount of increase in the 3dB frequency bandwidth of the microphone at different resonant frequencies may be represented by the change in the slope of the frequency bandwidth. In some embodiments, the range of slope variation of the microphone over a 3dB frequency bandwidth in the frequency range may be between 0.01Hz/Hz and 0.1Hz/Hz. In some embodiments, the range of slope variation of the microphone over a 3dB frequency bandwidth in the frequency range may be between 0.05Hz/Hz and 0.1Hz/Hz.
In some embodiments, the range of slope variation of the microphone over a 3dB frequency bandwidth in the frequency range may be between 0.02Hz/Hz and 0.06Hz/Hz.
In some embodiments, the amplification factor (which may also be referred to as gain) of the acoustic structure to the sound pressure of the sound signal may be expressed as equation (3):
wherein A is P To the sound pressure amplification factor, /) 0 Is the length of the sound guide tube, s is the cross-sectional area of the sound guide tube, and V is the volume of the acoustic cavity.
According to the formula (3), the sound pressure amplification factor of the acoustic structure to the sound signal is related to the length of the sound guide tube, the cross-sectional area of the sound guide tube and the volume of the acoustic cavity. Specifically, the sound pressure amplification factor of the acoustic structure to the sound signal is positively correlated with the length of the sound guide tube and the volume of the acoustic cavity, and is negatively correlated with the cross-sectional area of the sound guide tube.
According to equation (1), equation (3) can also be transformed into equation (4):
wherein A is P Denotes the sound pressure magnification, c 0 Denotes the speed of sound in air, l denotes the length of the sound guide tube, f the resonance frequency of the acoustic structure, and R denotes the radius of the acoustic cavity.
As can be seen from the equation (4), when other conditions (for example, the length of the sound guide tube, the radius of the acoustic cavity, and the like) are constant, the sound pressure amplification factor a of the acoustic structure with respect to the sound signal is constant p In relation to the resonance frequency f of the acoustic structure, in particular the sound pressure amplification a p Is inversely related to the resonant frequency f of the acoustic structure, and the smaller the resonant frequency f is, the sound pressure amplification factor A is p The larger and vice versa. That is, the acoustic structure has a relatively greater amplification of the sound signal at a relatively low resonant frequency (e.g., a resonant frequency in a mid-to-low frequency band). The resonance frequency, frequency bandwidth, amplification factor for a specific frequency component in a sound signal, sensitivity increment, Q value, and the like of the microphone can be changed by setting parameters of the acoustic structure. The parameters of the acoustic structure may comprise the shape of the sound guide tube, the size of the acoustic cavity, the sound guide tube or the acoustic cavityThe roughness of the inner surface of the side wall of the sound guide tube, the thickness of the sound absorbing material in the sound guide tube, etc. or combinations thereof.
Fig. 5 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 5, microphone 500 may include a housing 510, at least one acousto-electric converter 520 and an acoustic structure 530. One or more components of the microphone 500 shown in fig. 5 may be the same as or similar to one or more components of the microphone 200. For example, the case 510, the acousto-electric transducer 520, the aperture portion 521 of the acousto-electric transducer 520, the acoustic cavity 540, the application specific integrated circuit 550, etc. in the microphone 500 may be the same as or similar to the case 210, the acousto-electric transducer 220, the aperture portion 221 of the acousto-electric transducer 220, the acoustic cavity 240, the application specific integrated circuit 250, etc. in the microphone 200 shown in fig. 3. Unlike the acoustic structure 230 of microphone 200, the shape and/or location of the sound guide tube 532 in the acoustic structure 530 of microphone 500.
As shown in fig. 5, the acoustic structure 530 may include an acoustic cavity 531 and a sound guide tube 532. The acoustic cavity 531 may be in acoustic communication with the acousto-electric transducer 520 through the aperture portion 521 of the acousto-electric transducer 520. The acoustic cavity 531 may be in acoustic communication with the exterior of the microphone 500 through a sound guide tube 532. A first end of the sound guide tube 532 is positioned on the first sidewall 511 of the case 510, a second end of the sound guide tube 532 is positioned in the acoustic cavity 531, and a sidewall 533 of the sound guide tube 532 extends from the first sidewall 511 to the inside of the acoustic cavity 531. The external sound signal enters the inside of the sound guide tube 532 from the first end of the sound guide tube 532 and is transmitted to the acoustic cavity 531 from the second end of the sound guide tube 532. By providing that the second end of the sound guiding tube 532 extends into the acoustic cavity 531, the length of the sound guiding tube 532 and the volume of the acoustic cavity 531 may be increased without an additional increase in the size of the microphone 500. As can be seen from equation (1), increasing the length of the sound guide tube 532 and the volume of the acoustic cavity 531 lowers the resonant frequency of the acoustic structure 530 such that the frequency response curve of the microphone 500 has a resonance peak at a relatively low resonant frequency.
In some embodiments, the resonant frequency of the acoustic structure 530 may be further adjusted by setting the length, shape, etc. of the sound guide tube 532. By way of example only, fig. 6 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments herein. As shown in fig. 6, the sound guide tube 532 has a straight-line bending structure, a first end of the sound guide tube 532 is located on the first sidewall 511 of the housing 510, a second end of the sound guide tube 532 is located in the acoustic cavity 531, and the sidewall 533 of the sound guide tube 532 extends from the first sidewall 511 into the acoustic cavity 531. By providing the sound guide tube 532 in a curved shape, the length of the sound guide tube 532 may be increased while keeping the size of the acoustic cavity 531 not significantly reduced, so that the resonance frequency of the acoustic structure 530 may be lowered, and the sensitivity and Q-value of the response of the microphone 500 in the lower frequency range may be improved. In some embodiments, the structure of the sound guide tube 532 is not limited to the linear structure (e.g., shown in fig. 5), the linear bending structure (e.g., shown in fig. 6), but may be other structures, for example, an arc bending structure may be designed to reduce the acoustic resistance. In some embodiments, to adjust the acoustic resistance, the angle between two sections of the sound guide tube can be adjusted. For example, the included angle of the two tube centerlines may range from 60 to 150, and for example, the included angle of the two tube centerlines may range from 60 to 90. As another example, the centerline of the two tubes may be angled in the range of 90 to 120. The included angle of the midline of the two pipes can range from 120 degrees to 150 degrees.
In some embodiments, a first end of the sound guide tube 532 may be located outside of the enclosure 510 away from the first sidewall 511, a second end of the sound guide tube 532 may be located within the acoustic cavity 531, and a sidewall 533 of the sound guide tube 532 may extend from the sidewall 511 of the enclosure 510 into the acoustic cavity 531. By way of example only, fig. 7 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments herein. As shown in fig. 7, the sound guide tube 532 of the microphone 500 penetrates the first sidewall 511 of the case 510, a first end of the sound guide tube 532 extends away from the first sidewall 511 to the outside of the case 510 and is located outside the case 510, a second end of the sound guide tube 532 extends away from the first sidewall 511 to the inside of the acoustic cavity 531, and a second end of the sound guide tube 532 is located inside the acoustic cavity 531. External sound signals may enter the sound guide tube 532 from a first end of the sound guide tube 532 and be transmitted to the acoustic cavity 531 from a second end of the sound guide tube 532.
Fig. 8 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 8, microphone 800 may include a housing 810, at least one acousto-electric converter 820, and an acoustic structure 830. One or more components of microphone 800 shown in fig. 8 may be the same as or similar to one or more components of microphone 500 shown in fig. 5. For example, the housing 810, the acousto-electric converter 820, the aperture portion 821 of the acousto-electric converter 820, the acoustic cavity 840, the application specific integrated circuit 850, etc. in the microphone 800 may be the same as or similar to the housing 510, the acousto-electric converter 520, the aperture portion 521 of the acousto-electric converter 520, the acoustic cavity 540, the application specific integrated circuit 550, etc. in the microphone 500. The microphone 800 differs from the microphone 500 in the location and/or shape of the sound guide 832 of the acoustic structure 830.
As shown in fig. 8, the acoustic structure 830 may include an acoustic cavity 831 and a sound guide 832. The sound guide tube 832 may include one or more sidewalls, e.g., a sidewall 833 and a sidewall 834, to form the sound guide tube 832. In some embodiments, the sidewall 833 and the sidewall 834 can be one piece or different portions of the same sidewall of the sound guide tube 832. For example, the sidewalls 833 and 834 can be integrally formed. In some embodiments, the sidewalls 833 and 834 can be separate structures. In some embodiments, one or more sidewalls of the sound guide tube 832 may form an oblique angle with the central axis 835 of the sound guide tube 832. Taking the side wall 833 as an example, the side wall 833 of the sound guide tube 832 forms an inclination angle α with the central axis 835 of the sound guide tube 832. In some embodiments, as shown in fig. 8, assuming that the direction in which the central axis of the sound guide tube 832 points to the acoustic cavity 831 is a positive direction, when the aperture of the sound guide tube 832 is contracted inward along the positive direction of the central axis 835, that is, when the sidewalls 833 and/or 834 of the sound guide tube 832 are drawn together in the direction of the central axis 835 along the positive direction of the central axis 835 of the sound guide tube 832, the angle of the inclination angle α may be any number between 0 ° and 90 °. For example, the angle of the inclination angle α may be any value between 0 ° and 30 °. For another example, the angle of the inclination angle α may be any value between 30 ° and 45 °. For another example, the angle of the inclination angle α may be any value between 45 ° and 60 °. For another example, the angle of the inclination angle α may be any value between 60 ° and 90 °.
In some embodiments, as shown in fig. 9, when the aperture of the sound guide tube 832 expands outwardly in the positive direction of the central axis 835, i.e., the side walls 833 and/or the side walls 834 of the sound guide tube 832 extend away from the central axis 835 in the positive direction of the central axis 835 of the sound guide tube 832, the angle of the tilt angle β formed by the side walls 833 and/or the side walls 834 of the sound guide tube 832 and the central axis 835 of the sound guide tube 832 may be any number between 0 ° and 90 °. For example, the angle of the inclination angle β may be any value between 0 ° and 10 °. For another example, the angle of the inclination angle β may be any value between 10 ° and 20 °. For another example, the angle of the inclination angle β may be any value between 0 ° and 30 °. For another example, the angle of the inclination angle β may be any value between 30 ° and 45 °. For another example, the angle of the inclination angle β may be any value between 45 ° and 60 °. For another example, the angle of the inclination angle β may be any value between 60 ° and 90 °.
By setting the side walls of the sound guide tube 832 at an inclination angle to the central axis of the sound guide tube 832, the position of the resonance frequency of the microphone 800 may be adjusted without changing the length of the sound guide tube 832 and the outer diameter of the first end of the sound guide tube 832 (e.g., the end located on the first side wall 811 of the housing 810 or away from the first side wall 811 and outside the microphone 800). For example, when the aperture of the sound guide tube 832 is constricted inwardly in the positive direction of the center axis 835, the size of the cross-section of the second end of the sound guide tube 832 (e.g., the end extending into the acoustic cavity 831) may be reduced without changing the length of the sound guide tube 832 and the aperture of the first end of the sound guide tube 832, thereby reducing the resonant frequency of the acoustic structure 830. For another example, when the aperture of the sound guide tube 832 is expanded outward in the positive direction of the center axis 835, the size of the cross-section of the second end of the sound guide tube 832 may be increased without changing the length of the sound guide tube 832 and the aperture of the first end of the sound guide tube 832, thereby increasing the resonance frequency of the acoustic structure 830.
In some embodiments, when the cross-section of the acoustic cavity 831 (e.g., a cross-section parallel to the XZ plane) is circular, the aperture of the first end of the sound guide tube 832 may be no greater than 1.5 times the length of the sound guide tube 832. In some embodiments, the aperture of the first end of the sound guide 832 may be in the range of 0.1-3 millimeters and the length of the sound guide 832 may be in the range of 1-4 millimeters. In some embodiments, the aperture of the first end of the sound guide tube 832 may be in the range of 0.1-2 millimeters, and the length of the sound guide tube 832 may be in the range of 1-3 millimeters.
Fig. 10 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 10, the microphone 1000 may include a housing 1010, at least one acousto-electric converter 1020 and an acoustic structure 1030. The acoustic structure 1030 may include a sound guide tube 1032 and an acoustic cavity 1031. One or more components of the microphone 1000 shown in fig. 10 may be the same as or similar to one or more components of the microphone 200 shown in fig. 2A. For example, the case 1010, the acousto-electric transducer 1020, the aperture portion 1021 of the acousto-electric transducer 1020, the acoustic structure 1030, the acoustic cavity 1040, the application specific integrated circuit 1050, etc. in the microphone 1000 may be the same as or similar to the case 210, the acousto-electric transducer 220, the aperture portion 221 of the acousto-electric transducer 220, the acoustic structure 230, the acoustic cavity 240, etc. in the microphone 200 shown in fig. 3.
In some embodiments, the microphone 1000 differs from the microphone 200 in that the microphone 1000 may also include an acoustic resistance structure 1060. As can be seen from equation (2), the acoustically resistive structure 1060 can be used to adjust the frequency bandwidth of the acoustic structure 1030. In some embodiments, the acoustically resistive structure 1060 can include a film-like acoustically resistive structure, a mesh-like acoustically resistive structure, a plate-like acoustically resistive structure, or the like, or a combination thereof. In some embodiments, the acoustically resistive structure 1060 may include a single layer damping structure, a multi-layer damping structure, or the like, or other damping structures. The multilayer damping structure may comprise a single multilayer damping structure or a damping structure consisting of a plurality of single-layer damping structures.
In some embodiments, the acoustically resistive structure 1060 may be disposed in an outer surface of the sidewall 1033 forming the sound guide tube 1032 distal from the first sidewall 1011 of the housing 1010, an interior of the sound guide tube 1032, an inner surface of the first sidewall 1011, an outer surface of the first sidewall 1011, the acoustic cavity 1031, an inner surface of the second sidewall 1051 forming the aperture portion 1021 of the acousto-electric converter 1020, an outer surface of the second sidewall 1051, an interior of the aperture portion 1021 of the acousto-electric converter 1020, or the like, or combinations thereof.
As shown in fig. 10, the acoustic resistance structure 1060 may be provided in the form of a single-layer damping structure to the outer surface of the side wall 1033 forming the sound guide tube 1032, which is away from the first side wall 1011. The material, size, thickness, etc. of the acoustic resistance structure 1060 can be set according to actual needs. For example, the length of the acoustically resistive structure 1060 in the X-axis direction may be equal to the sum of the lengths of the sound guide tube 1032 and its side wall 1033. For another example, the length of the acoustic resistance structure 1060 in the X-axis direction may be equal to or greater than the aperture of the sound guide tube 1032. For another example, the width of the acoustic resistance structure 1060 in the Z-axis direction may be equal to or greater than the width of the sidewall 1033 of the sound guide tube 1032.
As shown in fig. 11, the acoustic resistance structure 1060 may be provided to the inner surface of the first sidewall 1011 in the form of a single-layer damping structure. In some embodiments, the acoustically resistive structure 1060 can be connected to one or more sidewalls of the housing 1010 (e.g., the sidewall 1011, the sidewall 1012, the sidewall 1013, etc. of the housing 1010). The material, size, thickness, etc. of the acoustic resistance structure 1060 can be set according to actual needs. For example, the length of the acoustically resistive structure 1060 in the X-axis direction may be less than or equal to the length of the sidewall 1011 of the housing 1010 in the X-axis direction. For another example, the width of the acoustic resistance structure 1060 in the Z-axis direction may be less than or equal to the width of the side wall 1011 of the housing 1010 in the Z-axis direction. Also for example, the size of the acoustically resistive structure 1060 may be larger, equal, or smaller than the aperture of the sound guide tube 1032.
As shown in fig. 12, the acoustic resistance structure 1060 may be provided in the acoustic cavity 1031 in the form of a single-layer damping structure, which may or may not be in contact with the side wall forming the sound guide tube 1032. For example, the two ends of the acoustically resistive structure 1060 can be connected to the side walls 1011 and/or the side walls 1013 of the housing 1010, respectively. As shown in fig. 13, the acoustic resistance structure 1060 may be provided in the form of a single-layer damping structure to the outer surface of the second side wall 1051 forming the hole portion 1021 of the acoustic-electric converter 1020, which may or may not be physically connected to the second side wall 1051. For example, the two ends of the acoustically resistive structure 1060 can be connected to the side walls 1012 and 1013, respectively, of the housing 1010. For another example, the acoustically resistive structure 1060 may be physically connected to the second sidewall 1051. In some embodiments, the size of the acoustically resistive structure 1060 may be the same as or different from the size of the second sidewall 1051. For example, the length of the acoustic resistance structure 1060 in the X-axis direction may be greater than, equal to, or less than the sum of the length of the second side wall 1051 in the X-axis direction and the aperture of the hole section 1021. In some embodiments, the size of the acoustically resistive structure 1060 may be larger than the size of the aperture portion 1021 of the acousto-electric converter 1020.
As shown in fig. 14, the acoustic resistance structure 1060 may be provided in the interior of the sound guide tube 1032 in the form of a single-layer damping structure, which may be connected to all or a part of the sidewall 1033 of the sound guide hole. In some embodiments, the material, size, thickness, etc. of the acoustic resistance structure 1060 may be set according to actual needs. For example, the thickness of the acoustic resistive structure 1060 in the Y-axis direction may be greater than, equal to, or less than the length of the sound guide tube 1032 in the Y-axis direction. For another example, the length of the acoustic resistive structure 1060 in the X-axis direction may be greater than, equal to, or less than the aperture of the sound guide tube 1032.
Fig. 15 is a schematic structural view of a microphone according to some embodiments of the present description, and as shown in fig. 15, the acoustic resistance structure 1060 may include a double-layer damping structure, which may include a first acoustic resistance structure 1061 and a second acoustic resistance structure 1062. The first acoustic resistance structure 1061 may be disposed on an outer surface of the sidewall 1033 forming the sound guide tube 1032 remote from the first sidewall 1011 of the housing 1010, which may or may not be physically connected to the outer surface of the first sidewall 1011. The second acoustically resistive structure 1062 may be disposed on an inner surface of the first sidewall 1011, which may or may not be physically connected to the inner surface of the first sidewall 1011. In some embodiments, the position, size, material, etc. of the first acoustic resistance structure 1061 and the second acoustic resistance structure 1062 may be set according to actual requirements, and they may be the same or different. For example, the first and/or second acoustically resistive structures 1061, 1062 may be disposed in the acoustic cavity 1031 (e.g., in physical connection with the second side wall 1051, the first side wall 1011, the side wall 1012, the side wall 1013, etc.). For another example, the first acoustic resistance structure 1061 and/or the second acoustic resistance structure 1062 may be disposed in the hole portion 1021 of the acoustic-electric converter 1020. Also for example, the first acoustic resistive structure 1061 and/or the second acoustic resistive structure 1062 may be disposed in the sound guide tube 1032. For another example, the first acoustic resistance structure 1061 and/or the second acoustic resistance structure 1062 may be disposed on an outer surface of the sidewall 1033 of the sound guide tube 1032.
In some embodiments, the acoustic resistance value of the acoustic resistive structure 1060 may be varied by adjusting parameters of the acoustic resistive structure 1060. In some embodiments, parameters of the acoustically resistive structure 1060 can include, but are not limited to, thickness, aperture, open porosity, etc. of the acoustically resistive structure 1060. In some embodiments, the thickness of the acoustically resistive structure 1060 can be 20-300 microns. In some embodiments, the thickness of the acoustically resistive structure 1060 may be 10 microns to 400 microns. In some embodiments, the aperture of the acoustically resistive structure 1060 may be 20 microns to 300 microns. In some embodiments, the aperture of the acoustically resistive structure 1060 may be between 30 microns and 300 microns. In some embodiments, the aperture of the acoustically resistive structure 1060 may be between 10 microns and 400 microns. In some embodiments, the open porosity of the acoustically resistive structure 1060 may be 10% -50%. In some embodiments, the open porosity of the acoustically resistive structure 1060 may be 30% -50%. In some embodiments, the open porosity of the acoustically resistive structure 1060 may be 20% -40%. In some embodiments, the open porosity of the acoustically resistive structure 1060 may be 25% -45%. In some embodiments, the acoustic resistance structure 1060 has acoustic resistance values ranging from 1MKS Rayls to 100MKS Rayls. In some embodiments, the acoustic resistance of the resistive structure 1060 can be made to be 10MKS Rayls-90 MKS Rayls, 20MKS Rayls-80 MKS Rayls, 30MKS Rayls-70 MKS Rayls, 40MKS Rayls-60 MKS Rayls, 50MKS Rayls by adjusting parameters (e.g., aperture, thickness, aperture ratio, etc.) of the resistive structure 1060.
In some embodiments, by providing a sound resistive structure in the microphone, the sound resistance of the sound resistive structure of the microphone may be increased, thereby adjusting the bandwidth (3 dB) and/or Q value of the frequency response of the microphone. In some embodiments, the degree to which the Q value of the frequency response of the microphone is affected by the acoustically resistive structures having different acoustic resistance values may be different. Fig. 16 is a frequency response curve of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 16, the horizontal axis represents frequency in Hz and the vertical axis represents the frequency response of the microphone in dB. A curve 1610 represents the frequency response of a microphone provided with no acoustic resistance structure, a curve 1615 represents the frequency response of a microphone provided with an acoustic resistance structure having an acoustic resistance value of 3MKS Rayls, a curve 1620 represents the frequency response of a microphone provided with an acoustic resistance structure having an acoustic resistance value of 20MKS Rayls, a curve 1630 represents the frequency response of a microphone provided with an acoustic resistance structure having an acoustic resistance value of 65MKS Rayls, a curve 1640 represents the frequency response of a microphone provided with an acoustic resistance structure having an acoustic resistance value of 160MKS Rayls, and a curve 1650 represents the frequency response of a microphone provided with an acoustic resistance structure having an acoustic resistance value of 4000MKS Rayls. As can be seen from fig. 16, as the sound resistance value of the sound resistance structure increases, the bandwidth of the frequency response curve of the microphone increases, and the frequency response of the microphone decreases. Therefore, the Q value of the microphone can be adjusted by setting the sound resistance value of the sound resistance structure of the microphone. In some embodiments, the Q value of the microphone decreases as the acoustic resistance value of the acoustic resistance structure increases, so that the acoustic resistance value of the acoustic resistance structure can be selected according to actual needs to obtain the target Q value and the target frequency bandwidth of the microphone. For example, the acoustic resistance value of the acoustic resistance structure may be set to not more than 20MKS Rayls, corresponding to a target frequency bandwidth (3 dB) of not less than 300Hz. For another example, the acoustic resistance value of the acoustic resistance structure may be not greater than 100MKS Rayls, and the corresponding target frequency bandwidth (3 dB) may be not less than 1000Hz.
Fig. 17 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 17, the microphone 1700 may include a housing 1710, at least one acousto-electric transducer 1720, an acoustic structure 1730 (which may also be referred to as a first acoustic structure), an acoustic cavity 1740, and an acoustic structure 1770 (which may also be referred to as a second acoustic structure). Acoustic structure 1730 may include sound guide tube 1732 (which may also be referred to as a first sound guide tube) and acoustic cavity 1731 (which may also be referred to as a first acoustic cavity). The acoustic structure 1770 can include a second acoustic cavity 1771 and a second sound guide tube 1772. One or more components of microphone 1700 may be the same as or similar to one or more corresponding components of microphone 300 shown in fig. 3. For example, the housing 1710, the at least one acousto-electric converter 1720, the acoustic structure 1730, the acoustic cavity 1740, the application specific integrated circuit 1750, etc. are the same as or similar to the housing 210, the at least one acousto-electric converter 220, the acoustic structure 230, the acoustic cavity 240, the application specific integrated circuit 250, etc. in the microphone 200 shown in fig. 3. The microphone 1700 differs from the microphone 200 in that the microphone 1700 may also include a second acoustic structure 1770. In some embodiments, the second acoustic structure 1770 may be disposed in series with the acoustic structure 1730. The second acoustic structure 1770 and the acoustic structure 1730 being arranged in series means that the second acoustic cavity 1771 of the second acoustic structure 1770 may be in acoustic communication with the acoustic cavity 1731 of the acoustic structure 1730 through the sound guide tube 1732 of the acoustic structure 1730. In some embodiments, the second acoustic cavity 1771 of the second acoustic structure 1770 is in acoustic communication with the exterior of the microphone 1700 through a second sound tube 1772. In some embodiments, the acousto-electric converter 1720 may include an aperture portion 1721, and the acoustic cavity 1731 may be in acoustic communication with the acousto-electric converter 720 through the aperture portion 1721. In some embodiments, the sound guide tube 1732 may be disposed on the cavity wall 1711 constituting the acoustic cavity 1731, and the second sound guide tube 1772 may be disposed on the cavity wall 1712 constituting the second acoustic cavity 1771.
In some embodiments, an external sound signal picked up by the microphone 1700 may be first conditioned (e.g., filtered) by the second acoustic structure 1770 and then transmitted to the acoustic structure 1730 through the sound guide tube 1732, and the sound signal is again conditioned by the acoustic structure 1730 and further enters the acoustic cavity 1740 of the microphone 1700 through the aperture portion 1721, thereby generating an electrical signal.
The structural parameters of acoustic structure 1730 may include the shape of sound guide tube 1732, the size of acoustic cavity 1731, the acoustic resistance of sound guide tube 1732 or acoustic cavity 1731, the roughness of the inner surface of the sidewall forming sound guide tube 1732, and the like, or combinations thereof. The structural parameters of the second acoustic structure 1770 may include the shape of the second sound tube 1772, the size of the second acoustic cavity 1771, the acoustic resistance of the second sound tube 1772 or the second acoustic cavity 1771, the roughness of the inner surface of the sidewall forming the second sound tube 1772, or the like, or combinations thereof. In some embodiments, the structural parameters of the second acoustic structure 1770 are the same as or different from the structural parameters of the acoustic structure 1730. For example, the acoustic structure 1770 may be in the shape of a cylinder and the acoustic structure 1730 may be in the shape of a cylinder. As another example, the acoustic resistance value of the acoustic structure 1770 may be less than the acoustic resistance value of the acoustic structure 1730. Reference may be made to fig. 2A, 3, and 5-15 and the associated description for the setting of structural parameters of the acoustic structure 1730 and/or the acoustic structure 1770.
In some embodiments, the acoustic-electric converter 1720 may have a second resonant frequency at which a frequency component of the sound signal resonates such that the acoustic-electric converter 1720 may amplify a frequency component of the sound signal near the second resonant frequency. The second acoustic structure 1770 can have a resonant frequency (also can be referred to as a third resonant frequency). The frequency component of the acoustic signal at the third resonant frequency resonates such that the second acoustic structure 1770 may amplify frequency components of the acoustic signal near the third resonant frequency. The acoustic structure 1730 may have a first resonant frequency at which the frequency component of the sound signal amplified by the second acoustic structure 1770 resonates such that the acoustic structure 1730 may continue to amplify frequency components of the sound signal near the first resonant frequency. Considering that a specific acoustic structure only has a good amplification effect on sound components in a specific frequency range, for convenience of understanding, a sound signal amplified by one acoustic structure may be regarded as a sub-band sound signal at a resonant frequency corresponding to the acoustic structure. For example, the sound amplified via the second acoustic structure 1770 described above may be viewed as a sub-band acoustic signal at the third resonant frequency, and a sound signal that continues to be amplified via the acoustic structure 1730 may result in another sub-band acoustic signal at the first resonant frequency. The amplified acoustic signal is transmitted to an acousto-electric converter 1720, thereby generating a corresponding electrical signal. In this manner, the acoustic structure 1730 and the second acoustic structure 1770 may increase the Q-value of the microphone 1700, and thus the sensitivity of the microphone 1700, in a frequency band including the first resonant frequency and the third resonant frequency, respectively, such that the sensitivity of the microphone 1700 response at the first resonant frequency is greater than the sensitivity of the acousto-electric transducer 1720 response at the first resonant frequency and/or such that the sensitivity of the microphone 1700 response at the third resonant frequency is greater than the sensitivity of the acousto-electric transducer 1720 response at the third resonant frequency. In some embodiments, the amount of increase in sensitivity of microphone 1700 (relative to the acoustic transducer) may be the same or different at different resonant frequencies. For example, when the third resonant frequency is greater than the first resonant frequency, the sensitivity of the microphone 1700 to respond at the third resonant frequency is greater than the sensitivity of the microphone 1700 to respond at the first resonant frequency. In some embodiments, the frequency response curve (e.g., resonant frequency, frequency response bandwidth (3 dB), Q value, etc.) of the acoustic structure 1770 and/or the acoustic structure 1730 may be adjusted by adjusting the structural parameters of the second acoustic structure 1770 and/or the acoustic structure 1730. For example, an acoustic resistive structure may be disposed in the second acoustic structure 1770 (e.g., the second sound tube 1772, the second acoustic cavity 1771, etc.) or the acoustic structure 1730 (e.g., the sound tube 1732, the acoustic cavity 1711, etc.) to adjust the frequency response bandwidth (3 dB) of the second acoustic structure 1770 or the acoustic structure 1730. For another example, the resonant frequency or the amplification factor of the acoustic structure 1730 may be adjusted by adjusting the aperture of the sound guide tube 1732, the length of the sound guide tube 1732, the volume of the acoustic cavity 1731, and the like. Similarly, the resonant frequency of the acoustic structure 1730 or the amplification of the acoustic signal can also be adjusted by adjusting the aperture of the second sound guide tube 1772, the length of the second sound guide tube 1772, the volume of the second acoustic cavity 1771, and the like. For example, the aperture of sound guide tube 1732 and/or second sound guide tube 1772 may be no greater than 2 times its length. Also for example, the roughness of the inner surface of the sidewall of sound guide tube 1732 and/or second sound guide tube 1772 is not greater than 0.8. As another example, the inner diameter of the acoustic cavity 1731 and/or the second acoustic cavity 1771 may be no less than its thickness. Reference may be made to fig. 2A, 3, and 5-15 and their associated descriptions for details regarding adjusting the frequency response curve of an acoustic structure by adjusting structural parameters of the acoustic structure.
In some embodiments, the first resonant frequency corresponding to the acoustic structure 1730 and the third resonant frequency corresponding to the second acoustic structure 1770 may be set according to practical circumstances. For example, the first resonance frequency and the third resonance frequency may be smaller than the second resonance frequency, so that the sensitivity of the microphone 1700 in the middle and low frequency bands may be improved. For another example, the absolute value of the difference between the first resonant frequency and the third resonant frequency may be less than a frequency threshold (e.g., 100Hz, 200Hz, 1000Hz, etc.), such that the sensitivity and Q of microphone 1700 may be improved over a range of frequencies. For another example, the first resonant frequency may be greater than the second resonant frequency (e.g., the difference between the first resonant frequency and the first resonant frequency is greater than 100 Hz), and the third resonant frequency may be less than the second resonant frequency (e.g., the absolute value of the difference between the third resonant frequency and the second resonant frequency may be not less than 100 Hz), so that the frequency response curve of microphone 1700 may be flatter, and the sensitivity of microphone 1700 in a wider frequency band may be improved.
The description of microphone 1700 above is for illustrative purposes only and is not intended to limit the scope of the present description. Various changes and modifications will occur to those skilled in the art based on the description herein. In some embodiments, microphone 1700 may include a plurality of acoustic structures (e.g., 3, 5, 11, 14, 64, etc.). In some embodiments, the connection of the acoustic structures in the microphone may be in series, parallel, or a combination thereof. In some embodiments, the magnitudes of the first resonant frequency, the second resonant frequency and the third resonant frequency can be adjusted according to actual needs. For example, the first resonant frequency and/or the third resonant frequency may be less than, equal to, or greater than the second resonant frequency. For another example, the first resonant frequency may be less than, equal to, or greater than the third resonant frequency. Such variations and modifications are intended to be within the scope of the present disclosure.
Fig. 18 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 18, the microphone 1800 may include a housing 1810, at least one acousto-electric converter 1820, an acoustic structure 1830, a second acoustic structure 1870 and a third acoustic structure 1880. One or more components of microphone 1800 may be the same as or similar to one or more components of microphone 1700 shown in fig. 17. For example, the housing 1810, the at least one acousto-electric transducer 1820, the acoustic structure 1830, the acoustic cavity 1840, the application specific integrated circuit 1850, etc. are the same as or similar to the housing 1710, the at least one acousto-electric transducer 1720, the acoustic structure 1730, the acoustic cavity 1740, the application specific integrated circuit 1750, etc. in the microphone 1700 shown in fig. 17. Microphone 1800 differs from microphone 1700 in that the number of acoustic structures included in microphone 1800, the manner of connection, etc., may differ from microphone 1700.
In some embodiments, the housing 1810 may be used to house one or more components (e.g., at least a portion of the acousto-electric transducer 1820, the acoustic structure 1830, the second acoustic structure 1870, and/or the third acoustic structure 1880) in the microphone 1800. In some embodiments, the housing 1810 may be an internally hollow structure that may form one or more acoustic cavities, e.g., the acoustic cavity 1840, the acoustic structure 1830, the second acoustic structure 1870, the third acoustic structure 1880, and/or the like. In some embodiments, the acoustic-to-electrical converter 1820 may be disposed in the acoustic cavity 1840. In some embodiments, the acousto-electric transducer 1820 may include an aperture portion 1821. The third acoustic structure 1880 may be in acoustic communication with the acousto-electric transducer 1820 through the aperture 1821. In some embodiments, the acoustic structure 1830 may include a sound guide tube 1831 and an acoustic cavity 1832, the second acoustic structure 1870 may include a second sound guide tube 1871 and a second acoustic cavity 1872, and the third acoustic structure 1880 may include a third sound guide tube 1881, a fourth sound guide tube 1882, and a third acoustic cavity 1883. The acoustic cavity 1832 may be in acoustic communication with the third acoustic cavity 1883 through a third sound guide 1881. The acoustic cavity 1832 may be in acoustic communication with the exterior of the acoustic microphone 1800 via a sound guide tube 1831. The second acoustic cavity 1872 may be in acoustic communication with the third acoustic cavity 1883 through a fourth sound guide 1882. The second acoustic cavity 1872 may be in acoustic communication with the exterior of the acoustic microphone 1800 via a second sound guide tube 1871. The third acoustic cavity 1883 may be in acoustic communication with the acousto-electric transducer 1820 through an aperture 1821 of the acousto-electric transducer 1820.
In some embodiments, the acoustic structure 1830 has a first resonant frequency, the acousto-electric transducer 1820 has a second resonant frequency, the second acoustic structure 1870 has a third resonant frequency, and the third acoustic structure 1880 has a fourth resonant frequency. In some embodiments, the first resonant frequency, the third resonant frequency, and/or the fourth resonant frequency may be the same as or different from the second resonant frequency. In some embodiments, the first resonant frequency, the third resonant frequency, and/or the fourth resonant frequency may be the same or different. For example, the first resonance frequency may be greater than 10000Hz, the second resonance frequency may be in the range of 500-700Hz, the third resonance frequency may be in the range of 700Hz-1000Hz, and the fourth resonance frequency may be in the range of 1000Hz-1300Hz, so that the sensitivity of the microphone 1800 in a wide frequency band may be improved. For another example, the first resonant frequency, the third resonant frequency, and the fourth resonant frequency may be smaller than the second resonant frequency, so that the frequency response and the sensitivity of the microphone 1800 in the mid-low frequency band may be improved. For another example, a part of the first resonant frequency, the third resonant frequency, and the fourth resonant frequency may be smaller than the second resonant frequency, and another part of the resonant frequency may be larger than the second resonant frequency, so that the sensitivity of the microphone 1800 in a wider frequency band range may be improved. For another example, the first resonant frequency, the third resonant frequency, and the fourth resonant frequency may be located in a specific frequency range, so that the sensitivity and the Q value of the microphone 1800 in the specific range may be improved.
When the microphone 1800 is used for sound signal processing, sound signals may enter the acoustic cavity 1832 of the acoustic structure 1830 through the sound guide tube 1831 and/or enter the second acoustic cavity 1872 of the second acoustic structure 1870 through the second sound guide tube 1871. The acoustic structure 1830 may condition the sound signal to generate a first sub-band sound signal having a first formant at a first resonant frequency. Similarly, the second acoustic structure 1870 may process the acoustic signal to generate a second sub-band acoustic signal having a second harmonic peak at the third resonance frequency. The first and/or second subband acoustic signals generated after conditioning by the acoustic structure 1830 and/or the second acoustic structure 1870 may enter the third acoustic cavity 1883 through the third and fourth sound guide tubes 1881 and 1882, respectively. The third acoustic structure 1880 may continue to adjust the first and second subband acoustic signals to generate a third subband acoustic signal having a third harmonic peak at a fourth harmonic frequency. The first, second, and third sub-band acoustic signals generated by the acoustic structure 1830, the second acoustic structure 1870, and the third acoustic structure 1880 may be transmitted through the aperture 1821 of the acousto-electric converter 1820 to the acousto-electric converter 1820. The acoustic-to-electric converter 1820 may generate an electrical signal from the first, second, and third sub-band acoustic signals.
It should be noted that the acoustic structures included in the microphone 1800 are not limited to the acoustic structures 1830, the second acoustic structure 1870, and the third acoustic structure 1880 shown in fig. 18, and the number of the acoustic structures included in the microphone 1800, the structural parameters of the acoustic structures, the number of the acoustic structures, the connection mode of the acoustic structures, and the like may be set according to actual needs (for example, a target resonant frequency, a target sensitivity, the number of subband electric signals, and the like). By way of example only, fig. 19 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments herein. As shown in fig. 19, the microphone 1900 may include a housing 1910, an acousto-electric converter 1920, an acoustic cavity 1940, an acoustic structure 1901, an acoustic structure 1902, an acoustic structure 1903, an acoustic structure 1904, an acoustic structure 1905, an acoustic structure 1906, and an acoustic structure 1907. An acousto-electric converter 1920 may be disposed in the acoustic cavity 1940. The acousto-electric converter 1920 may include an aperture 1921. The acoustic structure 1907 may include an acoustic cavity 1973 and 6 sound guide tubes in communication with the acoustic structure 1901, the acoustic structure 1902, the acoustic structure 1903, the acoustic structure 1904, the acoustic structure 1905, and the acoustic structure 1906, respectively. The microphone 1900 components and the processing of the sound signals are similar to the microphone 1800 in fig. 18, and will not be described again. Reference may be made to fig. 2A, 3, and 5-15, and associated descriptions, for details of adjustments in the frequency response curves (e.g., resonant frequency, frequency bandwidth, sound pressure amplification, etc.) of the acoustic structure 1830, the second acoustic structure 1870, and/or the third acoustic structure 1880 of fig. 18.
Fig. 20 is a schematic diagram of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 20, the microphone 2000 may include a housing 2010, an acoustic cavity 2040, an acousto-electric converter 2020, and an acoustic structure 2030. In some embodiments, the acoustic-to-electrical converter 2020 may be disposed in the acoustic cavity 2040. In some embodiments, the acoustic-electric converter 2020 may include a plurality of acoustic-electric converters, for example, an acoustic-electric converter 2021, a second acoustic-electric converter 2022, a third acoustic-electric converter 2023, a fourth acoustic-electric converter 2024, a fifth acoustic-electric converter 2025, and a sixth acoustic-electric converter 2026. In some embodiments, the acoustic structure 2030 may include a plurality of acoustic structures, such as acoustic structure 2031, second acoustic structure 2032, third acoustic structure 2033, fourth acoustic structure 2034, fifth acoustic structure 2035, and sixth acoustic structure 2036. In some embodiments, each acoustic structure in the microphone 2000 is disposed in correspondence with one acousto-electric transducer, for example, the acoustic structure 2031 is in acoustic communication with the acousto-electric transducer 2021 through an aperture portion of the acousto-electric transducer 2021, the second acoustic structure 2032 is in acoustic communication with the second acousto-electric transducer 2022 through an aperture portion of the second acousto-electric transducer 2022, the third acoustic structure 2033 is in acoustic communication with the third acousto-electric transducer 2023 through an aperture portion of the third acousto-electric transducer 2023, the fourth acoustic structure 2034 is in acoustic communication with the fourth acousto-electric transducer 2024 through an aperture portion of the fourth acousto-electric transducer 2024, the fifth acoustic structure 2035 is in acoustic communication with the fifth acousto-electric transducer 2025 through an aperture portion of the fifth acousto-electric transducer 2025, and the sixth acoustic structure 2036 is in acoustic communication with the sixth acousto-electric transducer 2026 through an aperture portion 2063 of the sixth acousto-electric transducer 2026. Taking the sixth acoustic structure 2036 as an example, the sixth acoustic structure 2036 comprises a sound guiding tube 2061 and an acoustic cavity 2062. The sixth acoustic structure 2036 is in acoustic communication with the exterior of the microphone 2000 via a sound guide tube 2061 for receiving sound signals. The acoustic cavity 2062 of the sixth acoustic structure 2036 is in acoustic communication with the acousto-electric converter 2026 through an aperture section 2063 of the acousto-electric converter 2026. In some embodiments, all of the acoustic structures in the microphone may correspond to one acoustic transducer. For example, the sound guide tubes of the acoustic structure 2031, the second acoustic structure 2032, the third acoustic structure 2033, the fourth acoustic structure 2034, the fifth acoustic structure 2035, and the sixth acoustic structure 2036 may be in acoustic communication with the exterior of the microphone 2000, respectively, and the acoustic cavities thereof may be in acoustic communication with the acoustic transducer. For another example, the microphone 2000 may include a plurality of acousto-electric transducers, and a portion of the acoustic structure 2031, the second acoustic structure 2032, the third acoustic structure 2033, the fourth acoustic structure 2034, the fifth acoustic structure 2035, and the sixth acoustic structure 2036 may be in acoustic communication with one of the plurality of acoustic transducers, and another portion of the acoustic structure may be in acoustic communication with another of the plurality of acoustic-electric transducers. For another example, the microphone 2000 may include a plurality of acousto-electric transducers, with the acoustic cavity of the acoustic structure 2031 being in acoustic communication with the acoustic cavity of the second acoustic structure via the sound guide of the second acoustic structure 2032, and the acoustic cavity of the second acoustic structure 2032 being in acoustic communication with the acoustic cavity of the third acoustic structure 2033 via the sound guide of the third acoustic structure 2033. The fourth acoustic structure 2034 may be in acoustic communication with the acoustic cavity of the fifth acoustic structure 2035 through the sound tube of the fifth acoustic structure 2035, and the acoustic cavity of the fifth acoustic structure 2035 may be in acoustic communication with the acoustic cavity 2062 of the sixth acoustic structure 2036 through the sound tube 2061 of the sixth acoustic structure 2036. The acoustic cavity of the third acoustic structure 2033 and the acoustic cavity 2062 of the sixth acoustic structure 2036 may be in acoustic communication with the same or different acousto-electric transducers. Such variations are within the scope of the present description.
In some embodiments, each of the acoustic structures 2030 may condition a received sound signal to generate a sub-band sound signal. The generated sub-band acoustic signals may be communicated to an acousto-electric converter in acoustic communication with each acoustic structure, which converts the received sub-band acoustic signals into sub-band electrical signals. In some embodiments, the acoustic structures in the acoustic structure 2030 may have different resonant frequencies, in which case the acoustic structures in the acoustic structure 2030 may generate sub-band acoustic signals having different resonant frequencies, and the corresponding acoustic-to-electrical converter in the acoustic-to-electrical converter 2020 may generate sub-band electrical signals having different resonant frequencies after conversion. In some embodiments, adjustment of the resonant frequency of one or more acoustic structures in microphone 2000 may be made with reference to fig. 2A, 3, and 5-15 and their associated descriptions. In some embodiments, the number of acoustic structures 2030 and/or acoustic-electric converters 2020 may be set as appropriate. For example, the number of acoustic structures 2030 and/or acoustic-electric converters 2020 may be set according to the number of sub-band acoustic signals and/or sub-band electric signals that need to be generated. For example only, when there are 6 sub-band electric signals to be generated, as shown in fig. 20, 6 acoustic structures may be provided, and the microphone 2000 may output 6 sub-band electric signals, whose resonance frequencies may be 500Hz-700Hz, 1000Hz-1300Hz, 1700Hz-2200Hz, 3000Hz-3800Hz, 4700Hz-5700Hz, 7000Hz-12000Hz, respectively. For another example, the resonance frequency ranges of the 6 sub-charged signals output by the microphone 2000 may be 500Hz-640Hz, 640Hz-780Hz, 780Hz-930Hz, 940Hz-1100Hz, 1100Hz-1300Hz, 1300Hz-1500Hz, respectively. For another example, the resonant frequency ranges of the 6 sub-charged signals output by the microphone 2000 may be 20Hz-120Hz, 120Hz-210Hz, 210Hz-320Hz, 320Hz-410Hz, 410Hz-500Hz, and 500Hz-640Hz, respectively.
In some embodiments, by placing one or more acoustic structures in the microphone, for example, acoustic structure 1730 and acoustic structure 1770 in microphone 1700, acoustic structure 1830, acoustic structure 1870 and acoustic structure 1880 in microphone 1800, acoustic structure 1901, acoustic structure 1902, acoustic structure 1903, acoustic structure 1904, acoustic structure 1905, and acoustic structure 1906 in microphone 1900, the resonant frequency of the microphone may be increased, which may in turn increase the sensitivity of the microphone over a wider frequency band. In addition, by providing a plurality of acoustic structures and/or a connection manner of the sound-electricity converter, for example, each acoustic structure in the microphone 2000 shown in fig. 20 is provided corresponding to one sound-electricity converter, so that the sensitivity of the microphone 2000 in a wide frequency band range can be improved, and the sound signal can be divided to generate a sub-band electric signal, thereby reducing the burden of subsequent hardware processing.
Fig. 21 is a schematic diagram of a frequency response curve of an exemplary microphone shown in accordance with some embodiments of the present description. As shown in fig. 21, the horizontal axis represents frequency in Hz, and the vertical axis represents frequency response of the microphone in dBV. Taking the example where the microphone includes 11 acoustic structures, the 11 dashed lines in fig. 21 represent the frequency response curves of the 11 acoustic structures. In some embodiments, the frequency response curves of the 11 acoustic structures may cover the 20Hz-20kHz frequency band range audible to the human ear. The solid line in fig. 21 represents the frequency response curve 2110 of the microphone. For ease of understanding, the frequency response curve 2110 of the microphone may be considered as a fusion of the frequency response curves of the 11 acoustic structures. In some embodiments, the adjustment to the target frequency response curve of the microphone may be achieved by adjusting the frequency response curve of one or more acoustic structures. For example, since the fundamental frequency of human voice is basically concentrated between about 100Hz and 300Hz, and most voice information is also concentrated in the range of middle and low frequency bands, the number of high frequency sub-band voice signals (i.e. the number of acoustic structures with resonant frequencies in high frequency band) can be reduced while ensuring that the conversation effect is not reduced after the processing of the sub-band voice signals. As another example, at the intersection of two or more acoustic structure frequency response curves (e.g., two adjacent frequency response curves), the fused resulting microphone frequency response curves may produce a pit. The pits herein may be understood as frequency response differences (e.g., Δ dBV shown in fig. 21) between adjacent peaks and valleys in the fused frequency response curve (e.g., curve 2110). The creation of pits may cause large fluctuations in the frequency response of the microphone, which in turn affects the sensitivity and/or Q-value of the microphone. In some embodiments, the resonant frequency of the acoustic structure may be reduced by adjusting structural parameters of the acoustic structure, such as, for example, reducing the cross-sectional area of the sound guide tube, increasing the length of the sound guide tube, and increasing the volume of the acoustic cavity. In some embodiments, the frequency bandwidth of the frequency response curve of the acoustic structure may be increased by adjusting structural parameters of the acoustic structure, for example, by providing a resistive structure in the microphone, etc., to reduce the larger pits generated by the fused frequency response curve 2110 in the high frequency range, thereby improving the performance of the microphone. For example, fig. 22 is a frequency response curve of an exemplary microphone shown in accordance with some embodiments herein. As shown in fig. 22, the horizontal axis represents frequency in Hz, and the vertical axis represents frequency response of the microphone in dBV. Wherein each dashed line may represent a frequency response curve of 11 acoustic structures of the microphone, respectively. The 11 acoustic structures corresponding to the 11 dashed lines in fig. 22 may have a relatively higher acoustic resistance than the 11 acoustic structures corresponding to the 11 dashed lines in fig. 21, for example, the inner surface of the sidewall of the sound guide tube of the 11 acoustic structures corresponding to the 11 dashed lines in fig. 22 is relatively rough, the sound guide tube or the acoustic cavity is provided with an acoustic resistance structure therein, the sound guide tube has a relatively small size, and the like. The response curve 2210 of the acoustic structure shown in fig. 22 (particularly the response curve for relatively higher frequencies) has a relatively wider frequency bandwidth than the frequency response curve 2110 of the acoustic structure in fig. 21. The notch (e.g., Δ dBV shown in fig. 22) of the frequency response curve of the microphone fused by the frequency response curves of the 11 acoustic structures is relatively small and the fused frequency response curve 2210 is flatter.
Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present specification. Various modifications, improvements and adaptations to the present description may occur to those skilled in the art, although not explicitly described herein. Such alterations, modifications, and improvements are intended to be suggested in this specification, and are intended to be within the spirit and scope of the exemplary embodiments of this specification.
Also, the description uses specific words to describe embodiments of the specification. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the specification. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the specification may be combined as appropriate.
Moreover, those skilled in the art will appreciate that aspects of the present description may be illustrated and described in terms of any number of patentable categories or situations, including any new and useful combinations of processes, machines, manufacture, or materials, or any new and useful modifications thereof.
Additionally, the order in which elements and sequences are referred to in the specification, the use of numerical letters or other designations do not limit the order of the processes and methods in the specification, unless otherwise indicated in the claims. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.
Similarly, it should be noted that in the foregoing description of embodiments of the present specification, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to imply that more features than are expressly recited in a claim. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.
Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially", etc. Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical data used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, numerical data should take into account the specified significant digits and employ a general digit preservation approach. Notwithstanding that the numerical ranges and data setting forth the broad scope of the range in some embodiments of the specification are approximations, the numerical values set forth in the specific examples are reported as precisely as possible within the scope of the application.
Claims (14)
1. A microphone, comprising:
a first acoustic structure comprising a first sound guide tube and a first acoustic cavity, the first acoustic structure having a first resonant frequency,
an acousto-electric converter for converting an acoustic signal into an electrical signal, the acousto-electric converter having a second resonant frequency,
a second acoustic structure comprising a second sound guide tube and a second acoustic cavity, the second acoustic structure having a third resonant frequency,
wherein the third resonant frequency is different from the first resonant frequency.
2. The microphone of claim 1 wherein the absolute value of the difference between the first resonant frequency or the third resonant frequency and the second resonant frequency is not less than 100Hz.
3. The microphone of claim 1 wherein the first resonant frequency is related to a structural parameter of the first acoustic structure, the second resonant frequency is related to a structural parameter of the acousto-electric transducer, and the third resonant frequency is related to a structural parameter of the second acoustic structure.
4. The microphone of claim 3,
the structural parameters of the first acoustic structure include one or more of a shape of the first sound guide tube, a size of the first acoustic cavity, an acoustic resistance of the first sound guide tube or the first acoustic cavity, a roughness of an inner surface of a sidewall forming the first sound guide tube,
the structural parameters of the second acoustic structure include one or more of a shape of the second sound guide tube, a size of the second acoustic cavity, an acoustic resistance of the second sound guide tube or the second acoustic cavity, and a roughness of an inner surface of a sidewall forming the second sound guide tube.
5. The microphone of claim 4, wherein the acoustic resistance has a value in the range of 1MKS Rayls to 100MKS Rayls.
6. The microphone as set forth in claim 1, wherein the first sound guide tube has an aperture no larger than 2 times its length, and the second sound guide tube has an aperture no larger than 2 times its length.
7. The microphone as set forth in claim 1, wherein the roughness of the inner surface of the side wall forming the first sound guiding tube or the second sound guiding tube is not more than 0.8.
8. The microphone of claim 1, wherein an inner diameter of the first acoustic cavity or the second acoustic cavity is not less than a thickness thereof.
9. The microphone of claim 1,
the sensitivity of the response of the microphone at the first resonance frequency is greater than the sensitivity of the response of the acousto-electric converter at the first resonance frequency, or
The sensitivity of the response of the microphone at the third resonant frequency is greater than the sensitivity of the response of the acousto-electric converter at the third resonant frequency.
10. The microphone of claim 1, wherein the first sound guide tube is disposed on a cavity wall constituting the first acoustic cavity, and the second sound guide tube is disposed on a cavity wall constituting the second acoustic cavity.
11. The microphone of claim 1 wherein the acousto-electric converter further comprises a first aperture portion through which the first acoustic cavity is in acoustic communication with the acousto-electric converter.
12. The microphone of claim 1 wherein the first acoustic cavity is in acoustic communication with the acousto-electric transducer and the second acoustic cavity is in acoustic communication with the exterior of the microphone through the second sound guide tube and is in acoustic communication with the first acoustic cavity through the first sound guide tube.
13. The microphone of claim 1,
the microphone further comprising a third acoustic structure comprising a third sound guide tube, a fourth sound guide tube and a third acoustic cavity,
the first acoustic cavity is in acoustic communication with the exterior of the microphone through the first sound conduction tube and in acoustic communication with the third acoustic cavity through the third sound conduction tube,
the second acoustic cavity is in acoustic communication with the exterior of the microphone through the second sound conduction pipe and is in acoustic communication with the third acoustic cavity through the fourth sound conduction pipe,
the third acoustic cavity is in acoustic communication with the acoustical-to-electrical converter, wherein,
the third acoustic structure has a fourth resonant frequency that is different from the third resonant frequency and the first resonant frequency.
14. The microphone of claim 11, further comprising a second acoustic-to-electric transducer, the second acoustic-to-electric transducer including a second aperture portion, the second acoustic cavity being in acoustic communication with an exterior of the microphone through the second sound guide tube and in acoustic communication with the second acoustic-to-electric transducer through the second aperture portion.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110919048.2A CN115706880A (en) | 2021-08-11 | 2021-08-11 | Microphone |
| TW111128293A TW202308404A (en) | 2021-08-11 | 2022-07-28 | Sound transmitter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110919048.2A CN115706880A (en) | 2021-08-11 | 2021-08-11 | Microphone |
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| Publication Number | Publication Date |
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| CN115706880A true CN115706880A (en) | 2023-02-17 |
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ID=85179763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110919048.2A Pending CN115706880A (en) | 2021-08-11 | 2021-08-11 | Microphone |
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| Country | Link |
|---|---|
| CN (1) | CN115706880A (en) |
| TW (1) | TW202308404A (en) |
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2021
- 2021-08-11 CN CN202110919048.2A patent/CN115706880A/en active Pending
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