CN110972018A - Method and system for carrying out transparent transmission on earphone and earphone - Google Patents
Method and system for carrying out transparent transmission on earphone and earphone Download PDFInfo
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- CN110972018A CN110972018A CN201911282376.5A CN201911282376A CN110972018A CN 110972018 A CN110972018 A CN 110972018A CN 201911282376 A CN201911282376 A CN 201911282376A CN 110972018 A CN110972018 A CN 110972018A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
- H04R1/1083—Reduction of ambient noise
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Abstract
The disclosure relates to a method and a system for transparent transmission of earphones and the earphones. The method comprises the following steps: determining a preset coefficient of a transmission filter and a preset transfer function of a transmission path from a loudspeaker to an in-ear microphone in the same state; determining a current transfer function of a transmission path from the speaker to the in-ear microphone while the speaker is playing the audio signal; determining a current system function of the pass-through filter according to a formula F2(z) ═ F1(z) · H1(z) · (1/H2(z)) based on a preset coefficient, a preset transfer function and a current transfer function, wherein F2(z) is a system function corresponding to the pass-through filter when the current coefficient is configured, F1(z) is a system function corresponding to the pass-through filter when the preset coefficient is configured, H1(z) is a preset transfer function of a transmission path from the speaker to the in-ear microphone, and H2(z) is a current transfer function of a transmission path from the speaker to the in-ear microphone, and represents a cascade of the connected system function and/or a filter corresponding to the transfer function; and configuring a pass-through filter with the current system function for pass-through.
Description
Technical Field
The present disclosure relates to the field of earphones, and more particularly, to a method and a system for transparent transmission to an earphone, and an earphone.
Background
With the social progress and the improvement of the living standard of people, the earphone becomes an indispensable living article for people. The earphone with the active noise suppression function can enable a user to enjoy comfortable noise reduction experience in various noisy environments such as airports, subways, airplanes, restaurants and the like, and is increasingly widely accepted by markets and customers. However, in some scenes where signals such as external voice or external environmental noise need to be received, the earphone needs to have a transparent transmission function while actively reducing noise, so that a user wearing the earphone can better receive the external voice, the external environmental noise or the external alarm sound. In addition, the perspective transmission function of the earphone is greatly influenced by different wearing modes and different ear structures, the listening experience of a user is influenced to a certain extent, the user is difficult to hear the natural environment sound when the earphone is not worn, and the earphone with the perspective transmission function can enable the user to hear the natural environment sound as close as possible to the natural environment sound when the earphone is not worn when the user wears the earphone.
Obviously, the existing earphones cannot solve the above problems.
Disclosure of Invention
The present disclosure is provided to solve the above-mentioned problems occurring in the prior art.
The utility model discloses need a scheme of passing through to the earphone, it can reduce different wearing methods and different duct structures to passing through the influence of system through the active adaptability adjustment to passing through the current coefficient of filter, improves the effect of passing through of earphone, promotes user's listening experience simultaneously.
According to a first aspect of the present disclosure, there is provided a method of pass-through transmission of an earphone, wherein the earphone includes an out-of-ear microphone, a pass-through filter, an in-ear microphone, and a speaker, the method comprising: determining a preset coefficient of a transmission filter and a preset transfer function of a transmission path from a loudspeaker to an in-ear microphone in the same state; determining a current transfer function of a transmission path from the loudspeaker to the in-ear microphone in case the loudspeaker is playing an audio signal; based on the preset coefficients of the pass-through filter, the preset transfer function of the transmission path from the loudspeaker to the in-ear microphone and the current transfer function, determining the current system function of the pass-through filter according to the following formula: f2(z) ═ F1(z) · H1(z) · (1/H2(z)), where F2(z) represents a system function corresponding to the pass-through filter when the current coefficient is configured, F1(z) represents a system function corresponding to the pass-through filter when the preset coefficient is configured, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the operation symbol · represents a cascade of filters corresponding to the system function and/or the transfer function connected thereto; and configuring the transparent transmission filter by using the determined current coefficient corresponding to the current system function so as to carry out transparent transmission.
According to the method for transparently transmitting the earphone, the influence of different wearing modes and different auditory canal structures on the transparently transmitting system can be reduced by actively adjusting the adaptability of the current coefficient of the transparently transmitting filter, the transparently transmitting effect of the earphone is improved, and the listening experience of a user is improved.
According to a second aspect of the present disclosure, there is provided a system for pass-through noise reduction of an earphone, wherein the earphone includes an out-of-ear microphone, a pass-through filter, an in-ear microphone, and a speaker, the system comprising: a first determination module configured to: determining a preset coefficient of a transmission filter and a preset transfer function of a transmission path from a loudspeaker to an in-ear microphone in the same state; a second determination module configured to: determining a current transfer function of a transmission path from the loudspeaker to the in-ear microphone in case the loudspeaker is playing an audio signal; a third determination module configured to: based on the preset coefficients of the pass-through filter, the preset transfer function of the transmission path from the loudspeaker to the in-ear microphone and the current transfer function, determining the current system function of the pass-through filter according to the following formula: f2(z) ═ F1(z) · H1(z) · (1/H2(z)), where F2(z) represents a system function corresponding to the pass-through filter when the current coefficient is configured, F1(z) represents a system function corresponding to the pass-through filter when the preset coefficient is configured, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the operation symbol · represents a cascade of filters corresponding to the system function and/or the transfer function connected thereto; and a pass-through filter configured with the determined current system function for pass-through noise reduction.
According to the method for transparently transmitting the earphone, the influence of different wearing modes and different auditory canal structures on the transparently transmitting system can be reduced by actively adjusting the adaptability of the current coefficient of the transparently transmitting filter, the transparently transmitting effect of the earphone is improved, and the listening experience of a user is improved.
According to a third aspect of the present disclosure, there is provided a headset comprising at least a memory, a processor, the memory having a computer program stored thereon, the processor realizing the steps of the method provided by the first aspect of the present disclosure when executing the computer program on the memory.
Above-mentioned earphone can reduce different wearing methods and different duct structures to the influence of passing through the system through the active adaptability adjustment to passing through the current coefficient of pass filter, improves the effect of passing through of earphone, promotes user's listening simultaneously and experiences.
Drawings
In the drawings, which are not necessarily drawn to scale, like reference numerals may describe similar components in different views. Like reference numerals having letter suffixes or different letter suffixes may represent different instances of similar components. The drawings illustrate various embodiments generally by way of example and not by way of limitation, and together with the description and claims serve to explain the disclosed embodiments. The same reference numbers will be used throughout the drawings to refer to the same or like parts, where appropriate. Such embodiments are illustrative, and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method.
Fig. 1 shows a schematic diagram of a headset pass-through process according to an embodiment of the present disclosure;
fig. 2 shows a flow diagram of a method of transparent transmission to an earphone in accordance with an embodiment of the present disclosure;
FIG. 3 shows a schematic diagram of determining preset coefficients according to an embodiment of the present disclosure;
FIG. 4 illustrates a schematic diagram of determining a preset transfer function according to an embodiment of the present disclosure;
FIG. 5 illustrates a schematic diagram of determining a current transfer function according to an embodiment of the present disclosure;
FIG. 6 shows a schematic diagram of a filtering process of an echo filter according to an embodiment of the disclosure;
fig. 7 shows a schematic diagram of a system for transparent transmission to an earphone in accordance with an embodiment of the present disclosure.
Detailed Description
For a better understanding of the technical aspects of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings. Embodiments of the present disclosure are described in further detail below with reference to the figures and the detailed description, but the present disclosure is not limited thereto. The order in which the various steps described herein are described as examples should not be construed as a limitation if there is no requirement for a context relationship between each other, and one skilled in the art would know that sequential adjustments may be made without destroying the logical relationship between each other, rendering the overall process impractical.
Fig. 1 shows a schematic diagram of a headset pass-through process according to an embodiment of the present disclosure. As shown in fig. 1, the headset implements a pass-through process through a feed-forward path and a feedback path at 100. In some embodiments, the earmicrophone 101a of the headset picks up ambient sound outside the headset on the feed-forward path. The collected ambient sound is subjected to gain processing by an analog gain 102a and analog-to-digital conversion by a first analog-to-digital converter 103a, and then is transmitted to a first low-pass and down-sampling filter 104 a. The first low pass and downsample filter 104a can reduce the filter sampling rate, thereby reducing power consumption and filter order, and further reducing chip area to reduce cost. Subsequently, the ambient sound signal passing through the first low-pass and down-sampling filter 104a is filtered by the pass-through filter 111 to simulate the ambient sound collected by the ear microphone 101 a. The ambient signal after the transparent transmission processing is transmitted to the adder 109, and then is processed by the digital-to-analog converter 106, and then is played by the speaker 107. The pass-through filtered ambient sound played through speaker 107 approximates the ambient sound when the user is not wearing the headset.
In some embodiments, in the feedback path, the in-ear microphone 101b of the earphone collects in-ear noise including an audio echo signal generated when the audio signal is played and a residual signal after air cancellation at a position inside the earphone near the ear canal. The collected in-ear noise is subjected to gain processing by an analog gain 102b and analog-to-digital conversion by a second analog-to-digital converter 103b, and then transmitted to a second low-pass and down-sampling filter 104 b. The second low pass and downsample filter 104b can reduce the filter sampling rate, thereby reducing power consumption and filter order, and further reducing chip area to reduce cost. Subsequently, the in-ear noise signal passing through the second low-pass and down-sampling filter 104b is transmitted to the adder 110. The audio signal to be played 105 is an audio signal to be transmitted to the speaker 107 for playing, and on one hand, it is transmitted to the adder 109, and after being processed by the digital-to-analog conversion of the digital-to-analog converter 106, it is played by the speaker 107; on the other hand, it is transmitted to an echo filter 112, the echo filter 112 is used to cancel the audio echo signal generated after the audio signal to be broadcast 105 is played by the loudspeaker 107, and then the audio signal to be broadcast 105 filtered by the echo filter 112 is fed to the adder 110. The adder 110 integrates the in-ear noise processed by the second low-pass and down-sampling filter 104b with the audio signal processed by the echo filter 112, so that the noise signal in the feedback path is no longer affected by the audio echo signal. The summer 110 then transmits the integrated noise signal to the feedback filter 112 for filtering to achieve feedback noise reduction. The feedback-filtered noise signal may be transmitted to the adder 109 through the limiter 108, and played back through the speaker 107 after being processed by the digital-to-analog converter 106. In some embodiments, the digital-to-analog converter 106 includes up-sampling and filtering circuitry to operate the digital-to-analog conversion process at higher frequencies; for example, when the adder 109 operates at 384kHz, the digital-to-analog conversion process of the digital-to-analog converter 106 operates at 384 × 64 — 24.576 MHz.
The above is a working principle of transparent transmission to the earphone based on the embodiment of the present disclosure, and the transparent transmission function of the earphone can be realized by respectively simulating the environmental sound on the feedforward path and filtering the noise on the feedback path, so as to improve the listening effect of the earphone. When the wearing posture of the earphone and the ear canal structure of the human ear affect the sound field in the ear, a transparent transmission scheme is needed to adjust the filter coefficient of the transparent transmission filter in time so as to adjust the adaptability of the changed sound field environment in time and achieve better transparent transmission effect.
Fig. 2 shows a flow chart of a method of transparently transmitting to an earphone according to an embodiment of the present disclosure, and as shown in fig. 2, a flow 200 starts with step 201, and at step 201, a preset coefficient of a transparent transmission filter and a preset transfer function of a transmission path from a speaker to an in-ear microphone in the same state are determined. In some embodiments, the same state may be that the predetermined coefficients of the pass-through filter and the predetermined transfer function of the transmission path from the speaker to the in-ear microphone are measured to obtain a better measurement result in case the earphone is placed in an artificial ear in a laboratory environment. The same state includes, but is not limited to, the above-described case as long as the state for determining the preset coefficient of the pass-through filter and the state for determining the preset transfer function of the transmission path from the speaker to the in-ear microphone are the same.
In step 202, when the user normally uses and wears the earphone, in the case where the speaker plays the audio signal, the audio signal is reflected by the ear canal after being played by the speaker, and is finally collected by the in-ear microphone, and in this process, the current transfer function of the transmission path from the speaker to the in-ear microphone can be determined.
At step 203, based on the settings of the pass-through filter of the earpiece, the coefficients, the preset transfer function of the speaker to the in-ear microphone of the earpiece, and the current transfer function of the pass-through filter determined in step 202, the current system function of the pass-through filter can be determined. The preset coefficient and the preset transfer function of the transmission filter are preset values obtained by measuring an earphone in an artificial ear canal for experiment in a laboratory. The present inventors have creatively found that the · operation result of the system function of the pass-through filter based on the pass-through system of the earphone under different conditions (different conditions are configured by different wearing manners and different ear canal structures) and the transfer function of the transmission path from the speaker to the in-ear microphone of the earphone is relatively fixed, for example, it does not change by more than 1db within 2k frequency, and thus the above-mentioned correspondence can be expressed as: f2(z) ═ F1(z) · H1(z) · (1/H2 (z)); wherein F2(z) represents a system function corresponding to the pass-through filter when the current coefficient is set, F1(z) represents a system function corresponding to the pass-through filter when the preset coefficient is set, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the arithmetic sign · represents a cascade of the system function and/or a filter corresponding to the transfer function to which it is connected. That is to say, when the sound field environment changes due to different wearing manners of the earphone and different ear canal structures of the human ear, considering that the preset coefficient and the preset transfer function are known, only the current transfer function of the transmission path from the loudspeaker to the in-ear microphone of the earphone under the current condition that the change occurs needs to be determined, and the system function of the pass-through filter under the current condition can be determined, so as to further determine the current coefficient of the pass-through filter. Specifically, the current coefficient of the pass-through filter may be determined as the coefficient corresponding to the system function F2 (z). In other words, the transmission filter can be understood as a filter configured by coefficients corresponding to F1(z), a filter having a transfer function of H1(z), and a filter having a system function of 1/H2(z) by being cascaded in sequence.
Subsequently, at step 204, the pass-through filter is configured with the current coefficients for pass-through. Therefore, the transparent transmission filter can be configured with the filter coefficient in a self-adaptive manner, and active adjustment of the transparent transmission system of the earphone is realized, so that influences on the transparent transmission system caused by different wearing modes and different ear canal structures are offset.
In some embodiments, the predetermined coefficients of the pass-through filter measured in step 201 may be obtained by: under the condition that the earphone is not placed in the artificial ear, acquiring an environmental noise signal through a microphone in the artificial ear; under the condition that the earphone is placed in the artificial ear, acquiring an in-ear noise signal of the artificial ear through an in-ear microphone of the artificial ear; and determining a preset coefficient meeting a preset condition based on the environment noise signal and the in-ear noise signal. The determination of the predetermined filter coefficients will be further explained with reference to fig. 3.
Fig. 3 shows an illustration of determining a preset coefficient according to an embodiment of the present disclosure, as shown in fig. 3, in 300, in case the headset is not placed in the artificial ear in the laboratory, the ambient noise 301a is acquired by the artificial in-ear microphone 303; in the case of placing the earphone in the artificial ear in a laboratory, the ambient noise 301c is acquired by the earphone's ear microphone 305, and the ambient noise 301c is transmitted to the pass-through filter 304 after passing through the analog-to-digital converter 302c, and then is played out by the speaker. Meanwhile, in the case where the earphone is put into the artificial ear in a laboratory, the in-ear noise 301b is collected by the artificial in-ear microphone 303. The pass-through filter 304 can determine a preset coefficient of the pass-through filter under laboratory conditions based on an ambient noise signal collected by the artificial in-ear microphone 303 when the earphone is not placed in the artificial ear and an in-ear noise signal collected by the artificial in-ear microphone 303 when the earphone is placed in the artificial ear. The coefficient of the pass-through filter 304 is continuously adjusted so that the in-ear noise signal collected by the artificial in-ear microphone 303 is as close as possible to the ambient noise 301 a. After the preset coefficient is obtained, the transparent transmission filter can be configured by the preset coefficient to transmit the noise signal in a transparent way, and then the noise signal is played through a loudspeaker, and the played noise is as close as possible to the environmental noise heard by the user when the user does not wear the earphone. It should be noted that, a laboratory can provide various environmental noises, and the experiment process can be repeated by playing the various environmental noises to determine the preset coefficient with better transparent transmission effect (meeting the preset condition).
In some embodiments, the predetermined transfer function of the pass-through filter measured in step 201 may be obtained by: under the condition that the earphone is placed in the artificial ear (note that the position where the earphone is placed in the artificial ear is the same as the position where the earphone is placed in the artificial ear when the preset coefficient of the transparent transmission filter is measured in a laboratory), the loudspeaker plays a first audio signal and acquires a first audio echo signal acquired by an in-ear microphone of the earphone; based on the first audio signal and the first audio echo signal, a preset transfer function of a transmission path of the loudspeaker to an in-ear microphone of the headset is determined. The determination of the preset transfer function will be further explained with reference to fig. 4.
Fig. 4 shows a schematic diagram of determining a preset transfer function according to an embodiment of the present disclosure, as shown in fig. 4, in 400, a headphone is placed in an artificial ear in a laboratory, and a first audio signal 401 is played by a speaker 403 via a digital-to-analog converter 402 a. On the one hand the first audio signal 401 is transmitted to an echo filter 406; on the other hand, the audio signal played by the speaker 403 is reflected by the ear canal and then collected by the in-ear microphone 404 of the earphone, and then analog-to-digital converted by the analog-to-digital converter 402b to obtain a first audio echo signal 405. The echo filter 406 is able to determine a preset transfer function of the transmission path from the loudspeaker of the headset to the in-ear microphone of the headset under laboratory preset conditions based on the first audio signal 401 and the first audio echo signal 405.
In some embodiments, when the earphone is placed in the human ear and the audio starts to play in step 202, the current transfer function from the speaker to the in-ear microphone of the earphone can be obtained by: responding to the loudspeaker to play the second audio signal, and acquiring a second audio echo signal acquired by an in-ear microphone of the earphone; based on the second audio signal and the second audio echo signal, a current transfer function of a transmission path of the loudspeaker to an in-ear microphone of the headset is determined. Determining the current transfer function is further described below in conjunction with fig. 5.
Fig. 5 shows a schematic diagram of determining a current transfer function according to an embodiment of the present disclosure, as shown in fig. 5, at 500, a user places an earpiece in the ear canal and a second audio signal 501 is played by a speaker 503 via a digital-to-analog converter 502 a. On the one hand the second audio signal 501 is transmitted to an echo filter 506; on the other hand, the audio signal played by the speaker 503 is reflected by the ear canal and collected by the in-ear microphone 504 of the earphone, and then is analog-to-digital converted by the analog-to-digital converter 502b to obtain a second audio echo signal 505. The echo filter 506 is able to determine, based on the second audio signal 501 and the second audio echo signal 505, a current transfer function of a transmission path of the loudspeaker to an in-ear microphone of the earphone when the user places the earphone in the ear canal and plays audio.
Thus, the preset coefficients of the pass-through filter, the preset transfer function of the transmission path from the loudspeaker to the in-ear microphone, and the current transfer function of the transmission path from the loudspeaker to the in-ear microphone obtained when the user wears the headset may be obtained by laboratory measurements based on the following correspondence: f2(z) ═ F1(z) · H1(z) · (1/H2(z)), to determine the system function of the pass-through filter in the current state, and further to determine its current coefficients. Wherein F2(z) represents a system function corresponding to the pass-through filter when the current coefficient is set, F1(z) represents a system function corresponding to the pass-through filter when the preset coefficient is set, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the arithmetic sign · represents a cascade of the system function and/or a filter corresponding to the transfer function to which it is connected. The transparent transmission filter is configured by the current coefficient, so that the transparent transmission system can adaptively adjust the transparent transmission coefficient, and the adaptive transparent transmission process aiming at the sound field change caused by different wearing postures and different ear canal structures is realized.
In some embodiments, when the user wears the headset, a second audio echo signal generated when the second audio signal is played by the speaker is filtered through an echo filter of the headset; and filtering the second audio echo signal collected by the microphone in the ear and the second audio echo signal filtered by the echo filter through a feedback filter of the earphone so as to realize feedback noise reduction. The process of filtering the second audio echo signal by the echo filter will be described in detail with reference to fig. 6.
Fig. 6 shows a schematic diagram of a filtering process of an echo filter according to an embodiment of the present disclosure, as shown in fig. 6, in 600, on one hand, an echo filter 602 filters an audio signal to be broadcasted 601, and then is transmitted to an adder 603; on the other hand, the in-ear microphone 607 collects an audio echo signal, passes through the analog gain 606 and the analog-to-digital converter 605, and the first low-pass and down-sampling filter 604a and the second low-pass and down-sampling filter 604b, and is then transmitted to the adder 603. The filtered audio signal passed to the echo filter 602 and the plurality of subsequently processed echo signals collected by the in-ear microphone 607, which are transmitted to the adder 603, are cancelled in the air, and the cancelled error signal is re-fed to the echo filter 602. From this, echo filter 602 can offset the broadcast audio in-process, because of the audio frequency echo component that the duct reflection produced, improves the noise reduction effect of earphone, promotes user's listening experience simultaneously for the audio signal of broadcast is not by the attenuation of the channel of making an uproar of falling of feedback.
In some embodiments, the transparent transmission filter in the active noise reduction method may be any one of a FIR filter and an IIR filter, the echo filter may be any one of a FIR filter and an IIR filter, and the feedback filter may be any one of a FIR filter and an IIR filter.
As an example, when each filter is an IIR filter, the correspondence may be directly utilized: f2(z) ═ F1(z) · H1(z) · (1/H2(z)), to determine the system function of the pass-through filter in the current state, and further to determine its current coefficients; wherein F2(z) represents a system function corresponding to the pass-through filter when the current coefficient is set, F1(z) represents a system function corresponding to the pass-through filter when the preset coefficient is set, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the arithmetic sign · represents a cascade of the system function and/or a filter corresponding to the transfer function to which it is connected.
H1(z) and H2(z) represent the transfer function of filter IIR, H (z) b (z)/a (z), b (z) bm*zm+bm-1*zm-1...b1*z1Is the molecular coefficient, A (z) ═ an*zn+an-1*zn-1...a1*z1H1(z) ═ B1(z)/a1(z), 1/H2(z) ═ a2(z)/B2(z), and F1(z) · H1(z) · (1/H2(z)) represent the cascade of filters corresponding to three system functions of F1(z), H1(z), and 1/H2(z), which are denominator coefficients.
As an example, when any of the filters corresponding to F1(z), H1(z), and 1/H2(z) is an FIR filter, the denominator coefficient corresponding to the system function thereof is 1. When the transmission filter is an IIR filter and the echo filter is an FIR filter, the current transfer function and the preset transfer function may be offset at the zero point in order to reduce the filter order for calculating the current transfer function.
As an example, when the filter is an FIR or IIR filter, fourier transform may be performed on the preset filter coefficient, the preset transfer function, and the current transfer function to obtain a corresponding frequency response, the frequency response of the current filter coefficient is obtained by calculation in the frequency domain, and then the current filter coefficient in the time domain is obtained by inverse fourier transform.
For example, the filter may be a filter group in which an FIR filter is combined with an IIR filter, and the FIR filter may be converted into the IIR filter at a high sampling rate after determining the coefficients of the FIR filter at a low sampling rate.
In some embodiments, the earphone mentioned in the above active noise reduction method includes any one of an in-ear earphone and a semi-in-ear earphone.
Fig. 7 shows a schematic diagram of a system for transparent transmission to an earphone according to an embodiment of the present disclosure, as shown in fig. 7, a system 700 comprising: a first determining module 701, a second determining module 702, a third determining module 703 and a transparent transmission filter 704; optionally and additionally, an echo filter 705 and a feedback filter 706 are included. Wherein the first determining module 701 may be configured to determine the preset coefficients of the pass-through filter and the preset transfer function of the transmission path from the speaker to the in-ear microphone in the same state; the second determination module 702 may be configured to determine a current transfer function of a transmission path from a speaker to the in-ear microphone in case the speaker plays an audio signal; the third determining module 703 may be configured to determine a current system function of the pass-through filter based on preset coefficients of the pass-through filter, a preset transfer function of a transmission path from the loudspeaker to the in-ear microphone, and the current transfer function according to the following formula: f2(z) ═ F1(z) · H1(z) · (1/H2(z)), where F2(z) represents a system function corresponding to the pass-through filter configuring the current coefficient, F1(z) represents a system function corresponding to the pass-through filter configuring the preset coefficient, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the arithmetic sign · represents a cascade of filters corresponding to the system function and/or transfer function to which it is connected; pass-through filter 704 may be configured to be configured with the determined current system function for pass-through.
In some embodiments, based on the schematic diagram of fig. 3 for determining the preset coefficient, the first determining module 701 in the system may be configured to determine the preset coefficient by: under the condition that the earphone is not placed in the artificial ear, acquiring an environmental noise signal through a microphone in the artificial ear; under the condition that the earphone is placed in the artificial ear, acquiring an in-ear noise signal of the artificial ear through an in-ear microphone of the artificial ear; determining a preset coefficient satisfying a preset condition based on the ambient noise signal and the in-ear noise signal.
In some embodiments, based on the schematic diagram of fig. 4 for determining the preset transfer function, the first determining module 701 in the system may be configured to determine the preset transfer function by: acquiring a first audio echo signal acquired by the in-ear microphone; determining the preset transfer function of the transmission path of the loudspeaker to the in-ear microphone based on the first audio signal and the first audio echo signal.
In some embodiments, based on the schematic diagram of determining the current transfer function shown in fig. 5, the second determining module 702 in the system is further configured to determine the current transfer function by: acquiring a second audio echo signal collected by the in-ear microphone under the condition that the loudspeaker plays the second audio signal; determining the current transfer function of a transmission path from the loudspeaker to the in-ear microphone based on the second audio signal and the second audio echo signal.
In some embodiments, the system further comprises: an echo filter 705 configured to filter the second audio echo signal; and a feedback filter 706 configured to filter the second audio echo signal collected by the in-ear microphone and the second audio echo signal filtered by the echo filter to implement feedback noise reduction.
In some embodiments, the pass-through filter 704 in the system is configured as any of an FIR filter and an IIR filter, the echo filter 705 is configured as any of an FIR filter and an IIR filter, and the feedback filter 706 is configured as any of an FIR filter and an IIR filter.
In some embodiments, the headphones in the system include any of in-ear headphones and semi-in-ear headphones.
Therefore, the transparent transmission system obtains the preset coefficient and the preset transfer function through measurement, obtains the current transfer function of the transparent transmission filter when a user wears the earphone, and determines the system function and the current coefficient of the transparent transmission filter in the current state based on the corresponding relation. The transparent transmission filter is configured by the current coefficient, so that the transparent transmission system can adaptively adjust the transparent transmission coefficient, and the adaptive transparent transmission process aiming at the sound field change caused by different wearing postures and different ear canal structures is realized.
According to a third aspect of the present disclosure, there is provided a headset comprising at least a memory, a processor, the memory having a computer program stored thereon, the processor realizing the steps of the method provided by the first aspect of the present disclosure when executing the computer program on the memory.
The earphone enables the transparent transmission system to adaptively adjust the transparent transmission filter coefficient through actively adjusting the current coefficient of the transparent transmission filter, and realizes the adaptive transparent transmission processing process aiming at sound field changes caused by different wearing postures and different ear canal structures.
Moreover, although exemplary embodiments have been described herein, the scope thereof includes any and all embodiments based on the disclosure with equivalent elements, modifications, omissions, combinations (e.g., of various embodiments across), adaptations or alterations. The elements of the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. It is intended, therefore, that the specification and examples be considered as exemplary only, with a true scope and spirit being indicated by the following claims and their full scope of equivalents.
The above description is intended to be illustrative and not restrictive. For example, the above-described examples (or one or more versions thereof) may be used in combination with each other. For example, other embodiments may be used by those of ordinary skill in the art upon reading the above description. In addition, in the foregoing detailed description, various features may be grouped together to streamline the disclosure. This should not be interpreted as an intention that a disclosed feature not claimed is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that these embodiments may be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
Claims (15)
1. A method of pass-through of an earphone, the earphone comprising an out-of-ear microphone, a pass-through filter, an in-ear microphone, and a speaker, the method comprising:
determining a preset coefficient of the pass-through filter and a preset transfer function of a transmission path from the loudspeaker to the in-ear microphone in the same state;
determining a current transfer function of a transmission path from the speaker to the in-ear microphone in a case where the speaker plays an audio signal;
determining a current system function of the pass-through filter according to the following equation (1) based on a preset coefficient of the pass-through filter, a preset transfer function of a transmission path from the speaker to the in-ear microphone, and the current transfer function:
f2(z) ═ F1(z) · H1(z) · (1/H2(z)) formula (1)
Wherein F2(z) represents a system function corresponding to the pass-through filter configuring the current coefficient, F1(z) represents a system function corresponding to the pass-through filter configuring the preset coefficient, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the operation symbol · represents a cascade of filters corresponding to the system function and/or transfer function to which it is connected; and
and configuring the transparent transmission filter by the determined current coefficient corresponding to the current system function so as to carry out transparent transmission.
2. The method of claim 1, wherein the predetermined coefficients are determined by:
acquiring an environmental noise signal through an artificial in-ear microphone under the condition that the earphone is not placed in an artificial ear;
acquiring an in-ear noise signal of the artificial ear through the artificial in-ear microphone under the condition that the earphone is placed in the artificial ear;
determining the preset coefficient satisfying a preset condition based on the ambient noise signal and the in-ear noise signal.
3. The method of claim 1, wherein the same state is that the earphone is placed in the artificial ear and the speaker plays a first audio signal, and wherein the predetermined transfer function is determined by:
acquiring a first audio echo signal acquired by the in-ear microphone;
determining the preset transfer function of the transmission path of the loudspeaker to the in-ear microphone based on the first audio signal and the first audio echo signal.
4. The method of claim 1, wherein determining a current transfer function of a transmission path from the speaker to the in-ear microphone comprises:
acquiring a second audio echo signal collected by the in-ear microphone under the condition that the loudspeaker plays the second audio signal;
determining the current transfer function of a transmission path from the loudspeaker to the in-ear microphone based on the second audio signal and the second audio echo signal.
5. The method according to any one of claims 1 to 4, further comprising:
filtering the second audio echo signal by an echo filter;
and filtering the second audio echo signal collected by the in-ear microphone and the second audio echo signal filtered by the echo filter through a feedback filter of the earphone so as to realize feedback noise reduction.
6. The method according to any one of claims 1 to 4, wherein the pass-through filter is any one of an FIR filter and an IIR filter, the echo filter is any one of an FIR filter and an IIR filter, and the feedback filter is any one of an FIR filter and an IIR filter.
7. The method of any of claims 1 to 4, wherein the headset comprises any of an in-ear headset and a semi-in-ear headset.
8. A system for pass-through noise reduction for an earphone, the earphone including an out-of-ear microphone, a pass-through filter, an in-ear microphone, and a speaker, the system comprising:
a first determination module configured to: determining a preset coefficient of the pass-through filter and a preset transfer function of a transmission path from the loudspeaker to the in-ear microphone in the same state;
a second determination module configured to: determining a current transfer function of a transmission path from the speaker to the in-ear microphone in a case where the speaker plays an audio signal;
a third determination module configured to: determining a current system function of the pass-through filter according to the following equation (1) based on a preset coefficient of the pass-through filter, a preset transfer function of a transmission path from the speaker to the in-ear microphone, and the current transfer function:
f2(z) ═ F1(z) · H1(z) · (1/H2(z)) formula (1)
Wherein F2(z) represents a system function corresponding to the pass-through filter configuring the current coefficient, F1(z) represents a system function corresponding to the pass-through filter configuring the preset coefficient, H1(z) represents a preset transfer function of a transmission path from the speaker to the in-ear microphone, H2(z) represents a current transfer function of a transmission path from the speaker to the in-ear microphone, and the operation symbol · represents a cascade of filters corresponding to the system function and/or transfer function to which it is connected; and
the pass-through filter configured to pass-through with the determined current system function.
9. The system of claim 8, wherein the first determination module is further configured to determine the preset coefficient by:
acquiring an environmental noise signal through an artificial in-ear microphone under the condition that the earphone is not placed in an artificial ear;
acquiring an in-ear noise signal of the artificial ear through the artificial in-ear microphone under the condition that the earphone is placed in the artificial ear;
determining the preset coefficient satisfying a preset condition based on the ambient noise signal and the in-ear noise signal.
10. The system of claim 8, wherein the first determining module is further configured to determine the preset transfer function by, in the case that the earphone is placed in an artificial ear and the speaker plays a first audio signal:
acquiring a first audio echo signal acquired by the in-ear microphone;
determining the preset transfer function of the transmission path of the loudspeaker to the in-ear microphone based on the first audio signal and the first audio echo signal.
11. The system of claim 8, wherein the second determination module is further configured to determine the current transfer function by:
acquiring a second audio echo signal collected by the in-ear microphone under the condition that the loudspeaker plays the second audio signal;
determining the current transfer function of a transmission path from the loudspeaker to the in-ear microphone based on the second audio signal and the second audio echo signal.
12. The system according to any one of claims 8 to 11, further comprising:
an echo filter configured to filter the second audio echo signal; and
a feedback filter configured to filter the second audio echo signal collected by the in-ear microphone and the second audio echo signal filtered by the echo filter to implement feedback noise reduction.
13. The system according to any one of claims 8 to 11, wherein the passthrough filter is configured as any one of a FIR filter and an IIR filter, the echo filter is configured as any one of a FIR filter and an IIR filter, and the feedback filter is configured as any one of a FIR filter and an IIR filter.
14. The system of any one of claims 8 to 11, wherein the headset comprises any one of an in-ear headset and a semi-in-ear headset.
15. A headset comprising at least a memory and a processor, the memory having stored thereon a computer program, characterized in that the processor, when executing the computer program on the memory, carries out the steps of the method according to any one of claims 1 to 7.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911282376.5A CN110972018B (en) | 2019-12-13 | 2019-12-13 | Method and system for carrying out transparent transmission on earphone and earphone |
| PCT/CN2020/082478 WO2021114514A1 (en) | 2019-12-13 | 2020-03-31 | Active noise control headphones |
| US16/836,919 US10834494B1 (en) | 2019-12-13 | 2020-04-01 | Active noise control headphones |
| US17/068,765 US11317192B2 (en) | 2019-12-13 | 2020-10-12 | Active noise control headphones |
| US17/151,545 US11330359B2 (en) | 2019-12-13 | 2021-01-18 | Active noise control headphones |
| US17/718,667 US11595748B2 (en) | 2019-12-13 | 2022-04-12 | Active noise control headphones |
| US17/975,921 US11653141B2 (en) | 2019-12-13 | 2022-10-28 | Active noise control headphones |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201911282376.5A CN110972018B (en) | 2019-12-13 | 2019-12-13 | Method and system for carrying out transparent transmission on earphone and earphone |
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| CN110972018A true CN110972018A (en) | 2020-04-07 |
| CN110972018B CN110972018B (en) | 2021-01-22 |
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