RU2804725C1 - Sound output device, method for adjusting imaginary source and method for adjusting volume - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: invention concerns sound output devices, a method for adjusting an imaginary source and a method for adjusting volume. The sound output device corrects the displacement of the imaginary sound source perceived by the user caused by differences in the mass of the first and second mechanical structures. In addition, the audio output device corrects the difference in volume between the first and second speakers caused by differences in the weight of the first mechanical structure and the second mechanical structure.

EFFECT: elimination of technical problems associated with differences in volume and displacement of the imaginary source caused by the uneven quality of the speakers on both sides of the bone conduction earphone.

15 cl, 9 dwg, 2 tbl

Description

Technical field

The present application concerns the acoustic field, in particular concerns sound output devices, a method for adjusting an imaginary source, and a method for adjusting volume.

State of the art

When using bone conduction headphones, the amplitude of vibration of bone conduction speakers is positively correlated with the volume they produce. In particular, the quality of the housing of bone conduction speakers significantly affects the amplitude of their vibrations, which, in turn, affects the volume produced by the speaker. In the design of a bone conduction headphone product, it is sometimes necessary to place additional functional modules on one side of the bone conduction speakers, such as a headset (with a microphone on the stem extension), keys, etc. Keys located on a bone conduction speaker change the distribution of mass on it, which affects the volume produced by the speaker. At the same time, since functional modules such as headset or keys only need to be placed on one side and not on the other, which results in discrepancy in the volume level of the speakers on both sides (the speaker volume in one ear is large and in the other ear is small) and causes a displacement of the imaginary source. If the volume of the left and right side speakers is very different, it may cause damage to the user's hearing if used for a long time. Therefore, it is necessary to adjust the imaginary source so that it is moderate and/or adjust the volume of the speakers on both sides of the headphones so that the volume of the speakers on both sides is the same.

Disclosure of the invention

The following is a brief overview of this application in order to obtain a general understanding of some of its aspects. It should be understood that this part is not intended to define the key or essential elements of this application or to limit the scope of this application. The purpose of this part is only to provide in a simplified form some of the concepts contained in this application. More detailed information will be set forth in detail elsewhere in this application.

As described above, for bone conduction headphones, a functional module additionally installed to the bone conduction speaker on one side increases the body mass of that bone conduction speaker, which leads to a decrease in the volume of the speaker on that side and different volumes of the left and right bone conduction headphones conductivity. When the volume difference between the left and right headphones is large, it will cause the imaginary source of the headphones to be noticeably shifted, and long-term use may even cause hearing damage.

To solve technical problems associated with differences in volume and imaginary source offset caused by uneven quality of speakers on both sides of a bone conduction earphone, the present application discloses an audio output device including: a signal processing circuit that, during operation, generates a first and second electrical signals based on target audio information; a first speaker electrically coupled to the signal processing circuit that, in operation, receives a first electrical signal from the signal processing circuit and converts the first electrical signal into a first sound wave; and a second speaker electrically coupled to the signal processing circuitry, in operation, receives a second electrical signal from the signal processing circuitry and converts the second electrical signal into a second sound wave, wherein the audio output device converts the target audio information into a first sound wave after a first time interval and converts the target audio information into a second audio wave over a second time interval, the first time interval being shorter than the second time interval by some time difference.

In some embodiments, the volume of the sound wave output from the first speaker is less than the volume of the sound wave output from the second speaker when input electrical signals are of the same amplitude and frequency.

In some embodiments, the difference between the volume of the first sound wave and the volume of the second sound wave is less than 3 dB when input electrical signals are of the same amplitude and frequency.

In some embodiments, the first speaker generates a first sound wave by energizing the first mechanical structure; and the second speaker generates a second sound wave by energizing the second mechanical structure, wherein the mass of the first mechanical structure is greater than the mass of the second mechanical structure such that the volume of the sound wave output from the first speaker is less than the volume of the sound wave output from the second speaker when the electrical signals are input with the same amplitude and frequency.

In some embodiments, the first speaker includes at least one of a first bone conduction speaker and a first air conduction speaker; and the second speaker includes at least one of a second bone conduction speaker and a second air conduction speaker.

In some embodiments, the time difference occurs as the audio output device converts the target audio information into a first electrical signal and a second electrical signal.

In some embodiments, a time difference occurs in the process of converting the first electrical signal into a first sound wave by the first speaker and the second electrical signal into a second sound wave by the second speaker.

In some implementations, the time difference is less than 3 ms.

The present application discloses an audio output device including: a signal processing circuit operative to generate first and second electrical signals based on target audio information; a first speaker electrically coupled to the signal processing circuit that, in operation, receives a first electrical signal from the signal processing circuit and converts the first electrical signal into a first drive such that the first mechanical structure generates a first sound wave; and a second speaker electrically coupled to the signal processing circuitry, which, in operation, receives a second electrical signal from the signal processing circuitry and converts the second electrical signal into a second drive such that the second mechanical structure generates a second sound wave, wherein the volume of the first sound wave is identical to the volume of the second sound wave; and under the same excitation, the sound volume generated by the first mechanical structure is lower than the sound volume generated by the second mechanical structure.

In some embodiments, the mass of the first mechanical structure is greater than the mass of the second mechanical structure such that, under the same excitation, the volume generated by the first mechanical structure is less than the volume generated by the second mechanical structure.

In some embodiments, the first speaker includes at least one of a first bone conduction speaker and a first air conduction speaker; and the second speaker includes at least one of a second bone conduction speaker and a second air conduction speaker.

In some embodiments, the first speaker further includes a first electromagnetic drive device that generates a first drive to vibrate the first mechanical structure and generate a first sound wave; and the second speaker further includes a second electromagnetic drive device that generates a second drive to vibrate the second mechanical structure and generate a second sound wave.

In some embodiments, the first electrical drive device includes a first coil; and the second electromagnetic excitation device includes a second coil, wherein the diameter of the winding of the first coil is larger than the diameter of the winding of the second coil.

In some embodiments, the first electromagnetic excitation device includes a first coil; and the second electromagnetic excitation device includes a second coil, wherein the electrical resistivity of the first coil is less than the electrical resistivity of the second coil.

In some embodiments, at the same input current, the first drive generated by the first electromagnetic drive device is greater than the second drive generated by the second electromagnetic drive device.

In some embodiments, the first speaker includes a first resistor; and the second speaker includes a second resistance, wherein the first resistance is less than the second resistance.

In some embodiments, the audio output device further includes power amplification circuitry coupled to the first speaker and signal processing circuitry that amplifies the first electrical signal, the first speaker receiving the amplified first electrical signal.

In some embodiments, the audio output device further includes power attenuation circuitry connecting the second speaker to the signal processing circuitry that attenuates the second electrical signal, wherein the second speaker receives the attenuated second electrical signal.

In addition, the present application discloses an imaginary source adjustment method for adjusting the imaginary source of the first speaker and the second speaker of the audio output device described above, the method including the steps of: obtaining a difference in volume of the first sound wave and the second sound wave; and adjust the time difference.

In some embodiments, the difference in volume between the first and second sound waves is less than 3 dB.

In some embodiments, the step of adjusting the time difference between the first sound wave and the second sound wave: adjusts the phase difference between the first sound wave and the second sound wave.

In addition, the present application discloses a volume control method for adjusting the volume of a first speaker and a second speaker of an audio output device, the method including the steps of: obtaining a difference in volume of a first sound wave and a second sound wave; and adjusting the difference in the amplitude values of the first excitation and the second excitation.

Thus, to solve the technical problems associated with differences in volume and imaginary source offset caused by uneven quality of speakers on both sides of a bone conduction earphone, the present application discloses an audio output device and a imaginary source adjustment method that corrects the imaginary source offset perceived by the user. , caused by differences in mass of the first and second mechanical structures, by establishing a time difference between the first and second sound waves.

The present application also provides an audio output device and volume control method that corrects the difference in volume between the left speaker and the right speaker caused by differences in the weight of the speakers of the left speaker and the right speaker in the mechanical structure by setting different coil resistivities, coil winding diameters, intensity magnetic field and/or resistance.

Brief description of drawings

Practical examples of the implementation of this application are described below. Among them, the same drawing mark denotes a similar structure in several kinds of drawings. For those skilled in the art, these exemplary embodiments are non-limiting, exemplary, the accompanying drawings are for illustration and description only and are not intended to limit the scope of the present disclosure, exemplary embodiments in other forms may similarly accomplish the inventive concept set forth herein. It should be understood that the drawings are not to scale. Including:

in fig. 1 is a diagram illustrating the appearance of an audio output device provided in accordance with certain embodiments of this application;

in fig. 2 is a design diagram of an audio output device provided in accordance with several embodiments of this application;

in fig. 3 shows a design diagram of an electromagnetic excitation device provided in accordance with several embodiments of this application;

in fig. 4 shows a design diagram of a bone conduction speaker provided in accordance with several embodiments of this application;

in fig. 5 is a diagram of the vibration model of a bone conduction speaker provided in accordance with several embodiments of this application;

in fig. 6 shows the results of testing the vibration strength of the housing during operation, supplied in accordance with some examples of implementation of this application;

in fig. 7 shows a design diagram of an electrodynamic speaker provided in accordance with several embodiments of this application;

in fig. 8 is a diagram of a volume control method provided in accordance with several embodiments of this application; And

in fig. 9 is a diagram of a method for adjusting an imaginary source provided in accordance with several embodiments of this application.

Carrying out the invention

The following is a description of specific scenarios and application requirements of this application to enable those skilled in the art to create and use the contents of this application. In view of the following description, these and other features of the present invention, as well as the operation and functions of the corresponding structural components, as well as the combination of components and the cost-effectiveness of manufacturing, can be significantly improved. As for the drawings, they are all part of this invention. However, it should be clearly understood that the drawings are for illustration and description purposes only and are not intended to limit the scope of the present invention. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but can have the widest scope of application in accordance with the claims.

As used herein, bone conduction sound waves refers to sound waves that mechanical vibration conducts into the inner ear through the bones of the skull (also called bone conduction sound), and air conduction sound waves refers to sound waves that mechanical vibration conducts into the inner ear. through air (also called air-conducted sound).

The present application presents a method for adjusting volume. The volume control method can be used to adjust the volume of sound waves output by an audio output device. Sound waves may include bone conduction/air conduction sound waves. The audio output device may include, but is not limited to, headphones, hearing aids, helmets, etc. Headphones may include, but are not limited to, wired headphones, wireless headphones, Bluetooth headsets, and so on. The headphones may include, but are not limited to, a bone conduction speaker, an air conduction speaker.

In fig. 1 is a diagram showing the appearance of an audio output device 300 provided in accordance with an embodiment of this application. In fig. 2 shows a design diagram of an audio output device 300 provided in accordance with an embodiment of this application. See FIG. 2, audio output device 300 may include a first speaker 310, a second speaker 320, and signal processing circuitry 330.

The signal processing circuit 330 may receive the target audio information 10, process the target audio information 10, and generate a first electrical signal 11 and a second electrical signal 12.

The target audio information 10 may include videos, audio files with a specific data format, or data or files that can be converted to sound in certain ways. The target audio information 10 may come from the storage of the audio output device 300 itself or from an information generation, storage, or transmission system external to the audio output device 300. The target audio information 10 may include one or more combinations of electrical, optical, magnetic, or mechanical signals. The target audio information 10 may come from one or more signal sources. Multiple signal sources can be either interconnected or non-interconnected. In some embodiments, signal processing circuitry 330 may obtain target audio information 10 in several different ways. The target audio information 10 is received, may be wired or wireless, and may be in real time or delayed. For example, audio output device 300 may receive target audio information 10 via a wired or wireless method, or may receive data directly from a storage medium to generate target audio information 10. For example, audio output device 300 may include components with an audio collection function that convert mechanical vibration sound into an electrical signal by collecting sound in the environment, using a shaper amplifier will receive electrical signals that meet certain requirements. In some embodiments, wired communications may include metallic cables, optical cables, or combined metallic and optical cables, such as coaxial cables, communication cables, flexible cables, spiral cables, non-metallic sheathed cables, metallic sheathed cables, multi-core cables, cables with twisted pair cables, ribbon cables, shielded cables, electrical core cables, two-core cables, parallel two-core wires, twisted pair and other combinations. The options described above are for illustrative purposes only, and wire-connected intermediaries may also be in other forms, such as other electrical or optical signal transmission media, etc. Wireless communications may include radio communications, free-space optical communications, acoustic communications, and electromagnetic induction. For wireless communication, radio communications of the IEEE802.11 standard, IEEE802.15 standard (for example, Bluetooth technology and cellular communications, etc.), first generation mobile communications, second generation mobile communications (for example, FDMA, TDMA, SDMA, CDMA and SSMA) can be used. , public packet radio system technology, third generation mobile communications (e.g. CDMA2000, WCDMA, TD-SCDMA and WiMAX), fourth generation mobile communications (e.g. TD-LTE and FDD-LTE), satellite communications (e.g. GPS), Near Field Communication (NFC) and other technologies operating in the ISM band (e.g. 2.4 GHz); Free space optical communications may include VLC and infrared signals; acoustic communication may include sound, ultrasonic signals, etc.; electromagnetic induction may include, for example, near field communication technology. The options described above are for illustrative purposes only, and the wireless communication medium may be in other forms, such as Z-wave technology, other toll civil and military radio frequency bands, etc. For example, as one application scenario of this application, audio output device 300 may receive specified target audio information 10 from other devices using Bluetooth technology.

In some embodiments, in order for the first audio wave 21 and the second audio wave 22 to have certain output characteristics (e.g., frequency, phase, amplitude, etc.), signal processing circuitry 330 may process the target audio information 10 such that the first electrical signal 11 and second electrical signal 12 output from signal processing circuit 330 respectively had a specific frequency component.

In some embodiments, multiple wave filters/wave filter groups 331 are installed in the signal processing circuit 330. The multiple wave filters/wave filter groups 331 may couple received electrical signals for processing and output electrical signals containing different frequencies. Wave filters/wave filter banks 331 include, but are not limited to, analog filters, digital filters, passive filters, active filters, etc. In some embodiments, a dynamic range controller 332 is installed in the signal processing circuit 330. The dynamic range controller 332 is capable of compressing and amplifying the input signal to make the sound softer or louder. In some embodiments, an implementation may install active audio leakage reduction circuitry 333 in signal processing circuitry 330 to reduce audio leakage of audio output device 300. In some embodiments, feedback circuitry 334 is installed in signal processing circuitry 330. Feedback circuitry 334 may transmit information about sound field to signal processing circuit 330. In some embodiments, signal processing circuit 330 may include a power control circuit 335 that adjusts the amplitudes of the received electrical signal. Power control circuit 335 may include power amplification circuitry to amplify the signal of the first electrical signal 11 and/or second electrical signal 12. Power control circuitry 335 may also include power attenuation circuitry to attenuate the signal amplitude of the first electrical signal 11 and/or the second electrical signal. 12. In some embodiments, it may be possible to install an equalizer 338 in the signal processing circuit 330. The equalizer 338 is capable of separately amplifying or attenuating the received signal over a specific frequency range. In some embodiments, the signal processing circuit 330 may include a frequency division circuit 339. The frequency division circuit allows the received electrical signals to be divided into high frequency component signals and low frequency component signals.

The first speaker 310 is electrically coupled to the signal processing circuit 330. The first speaker 310 may receive the first electrical signal 11 from the signal processing circuit 330 and convert the first electrical signal 11 into a first sound wave 21. The first speaker 310 may be a power conversion device. In some embodiments, the first speaker 310 may convert the received first electrical signal 11 into mechanical vibration. Moreover, the first sound wave 21 is generated by mechanical vibrations. For example, the first speaker 310 may include a first mechanical structure 311 and a first driver 312. In some embodiments, the first speaker 310 may be a bone conduction speaker; the first speaker 310 may also include an air conduction speaker or a bone conduction speaker and an air conduction speaker.

The first driver 312 may be an input to a power conversion device. The first driver 312 may receive the first electrical signal 11 from the signal processing circuit 330 and convert the first electrical signal 11 into a first drive. The first excitation excites vibration of the first mechanical structure 311. That is, through the first excitation device 312 and the first mechanical structure 311, the first speaker 310 converts the electrical energy received from the first electrical signal 11 into mechanical vibration energy of the first mechanical structure 311.

The first driver 412 provides a first drive to vibrate the first mechanical structure 411. In some embodiments, the first driver 412 may employ an electromagnetic driver. The first excitation may be a magnetic field force, an electromagnetic force, and/or an Ampere force generated by an electromagnetic excitation device. Of course, the first driver 412 may also be another type of driver, and this application is not particularly limited. The driver receives the first electrical signal 11 from the signal processing circuit 430 and generates the first drive. Methods for generating the first excitation by the exciter may include, but are not limited to, variable coil, electrostatic, piezoelectric, ferrodynamic, pneumatic, electromagnetic, etc.

As an example, in FIG. 3 shows a design diagram of a first driver 412 provided in accordance with an embodiment of this application. The first driver 412 shown in FIG. 3, may be an electromagnetic exciting device. In particular, the first driver 412 may include a magnetic piece 610 and a coil 620.

The magnetic piece 610 can generate a magnetic field. For example, magnetic piece 610 may have magnetic properties. In some embodiments, the magnetic properties may be permanent. Magnetic piece 610 may include or be made of a permanent magnet. Permanent magnets can be either natural or artificial. By way of example, a permanent magnet may include, but is not limited to, NdFeB magnets, magnets, etc. The permanent magnet must have the highest possible coercivity, remanent magnetism, and maximum energy product to ensure the permanent magnet's stable magnetic properties and the ability to store maximum magnetic energy .

The bobbin 620 may be a group of twisted threads wound in a particular direction. Coil 620 may be mounted in a magnetic field generated by magnetic piece 610. Coil 620 may be comprised of a first end 621 and a second end 622. An electrical signal may enter coil 620 as a current from first end 621, flow through coil 620, and flow out of the coil. 620 from the second end 622.

Based on knowledge of electromagnetism, it is known that the energized coil 620 experiences Ampere forces in a magnetic field. In addition, the magnitude of the Ampere force can be determined by F=B·I·L. Where F denotes the amount of Ampere force to which the coil 620 is subjected; the orientation of F can be determined by the ampere rule. F causes coil 620 to vibrate. The coil 620 may couple the mechanical structure 630, furthermore, the coil 620 causes the mechanical structure 630 to vibrate. As an example, the mechanical structure 630 may be the first mechanical structure 311 that produces the first sound wave 21. That is, F, as an external driving signal, causes the first mechanical structure 311 to oscillate.

B is the magnetic field strength produced by magnetic piece 610. The magnitude of the magnetic field strength produced by magnetic piece 610 is correlated with the material of magnetic piece 610. In some embodiments, the magnitude of the magnetic field strength B produced by magnetic piece 610 is positively correlated with the coercivity of the magnetic piece. 610, residual magnetism and maximum accumulation of magnetic energy.

I is the amount of current passing through coil 620. I is correlated with the electrical signal received by first driver 412. Typically, the electrical signal is applied to coil 620 in the form of a pulsed voltage. In U _t represents the magnitude of the pulse voltage between the first end 621 and the second end 622 of the coil 620 (ie, the electrical signal supplied to the electromagnetic excitation device 600). Then the current I flowing through the coil 620 is represented by I = U _t /R. Where R represents the amount of resistance between the first end 621 and the second end 622. And based on the knowledge of physics, the amount of resistance between the first end 621 and the second end 622 is calculated based on . Where, ρ is the specific resistance of the coil winding 620; L - coil length 620; S - coil winding diameter 620.

Thus, it can be obtained that the driving amount F (Ampere force per coil) generated by the first driving device 412 is:

Further in Fig. 2, the first mechanical structure 311 may be an output of a power conversion device. The first mechanical structure 311 vibrates to generate the first sound wave 21. The first mechanical structure 311 may generate mechanical vibration under the action of the first excitation; furthermore, the first sound wave 21 is generated based on mechanical vibration. In some embodiments, the first mechanical structure 311 may be an element that, when excited, produces sound directly through vibration. For example, the first mechanical structure 311 may be a bone conduction speaker housing if the first speaker is a bone conduction speaker. The first mechanical structure 311 may include fine wool cones or paper cones for electrodynamic air conduction speakers if the first speaker is an air conduction speaker.

Since the first sound wave 21 is generated by vibration of the first mechanical structure 311, in order to analyze the characteristics of the first sound wave 21, it is necessary to analyze the vibration process of the first mechanical structure 311. In the following description of the invention according to this application, as an example, a bone conduction speaker is used for the first speaker 310 , analyzes the vibration process of the first mechanical structure 311.

In fig. 4 shows a design diagram of a bone conduction speaker 100 provided in accordance with several embodiments of this application. The bone conduction speaker 100 may include a housing 120 and a magnetic circuit 130.

The magnetic circuit 130 may serve as a driving device for generating excitation f. The magnetic circuit 130 and the housing 120 are connected by a plate to effect transmission of vibrations 140.

The housing 120 may be attached to the earphone 110. The top point P of the earphone 110 fits well against the head. Thus, the top point P can serve as a fixed point. The housing 120 can vibrate under the action of excitation f and generate sound waves when the bone conduction speaker 100 is operated. Due to the interaction of forces, as the housing 120 vibrates, the magnetic circuit 130 is also subjected to a force corresponding to the value of f in the opposite direction (“-f” as shown in the figure). To facilitate analysis of the relationship between the sound waves produced by the bone conduction speaker 100 and the housing 120 and magnetic circuit 130, the housing 120 and magnetic circuit 130 can be reduced to a two-degree-of-freedom vibration system.

In fig. 5 shows a model of a vibration system with two degrees of freedom, presented in accordance with an embodiment of this application. In the model according to Fig. 5: mass block m1 may represent housing 120; the mass block m2 may represent the magnetic circuit 130; the elastic connection k1 may be a plate for effecting vibration transmission 140; the elastic connection k2 may represent the earphone 110. The dampings of the elastic connections k1 and k2 respectively represent c1 and c2. The housing 120 and the magnetic circuit 130 vibrate under the action of a force f and a force -f, respectively. f is the excitation size of the system; direction f as shown in Fig. 5. A composite vibration system consisting of a body 120, a magnetic circuit 130, a vibration transmission plate 140 and an earphone 110 is provided at the top point P of the earphone 110.

By kinetic analysis of the housing 120 and the magnetic circuit 130, respectively, the dynamics equation of the two-degree-of-freedom vibration model shown in FIG. 5:

From the Fourier transform it is known that any excitation f can achieve a series of sums of pure harmonic vibrations in the table of frequency fields, therefore, under the assumption that , where F ₀ is the exciting amplitude, the response of the system in a steady state can be expressed as , Where - response amplitude.

When putting F and X into formula (2), it leads to formula (3).

The mechanical impedance matrix Z (ω) is introduced:

The mechanical impedance matrix Z (ω) is substituted into formula (3), and the response amplitude of the vibration system is obtained by solving:

,

Where:

Thus, it is possible to obtain the response amplitude of the vibration system:

The housing 120 vibrates, creating sound waves. Thus, the body 120 (ie the mass block m ₁ ) is analyzed. the mechanical impedance matrix Z(ω) is substituted into formula (4), the amplitude of the reaction of the housing 120 is obtained:

... formula (6)

From formula (6) it is clear that during forced vibration, the vibration amplitude X ₁ of the housing 120 is influenced by the following parameters: excitation frequency f (value equal to 1/ω), excitation amplitude F ₀ f, housing mass 120 m ₁ , magnetic circuit mass 130 m ₂ , the rigidity _k1 of the vibration transmission plate is 140 and the damping _c1 , and the stiffness _k2 of the earphone is 110 and the damping _c2 . For example, if other parameters are kept unchanged, the excitation amplitude F ₀ f is positively correlated with the vibration amplitude X ₁ of the housing 120. The greater the excitation amplitude F ₀ f, the greater the vibration amplitude X ₁ of the housing 120. For example, if other parameters are kept unchanged, the more mass m ₁ of the housing 120 of the speaker with bone conduction 100, the lower the amplitude of oscillations X ₁ of the housing 120; The larger the mass m ₂ of the magnetic circuit 130, the greater the vibration amplitude X ₁ of the housing 120. Thus, when the above parameters change, the amplitude X ₁ of the housing 120A changes along with it. The amplitude X ₁ of the housing 120, without taking into account the difference between the transmission medium and the transmission distance, is positively correlated with the loudness of the sound waves generated by the vibration of the housing 120. The larger the amplitude X ₁ , the louder the sound wave; the smaller the amplitude X ₁ , the lower the volume of the sound wave.

In fig. 6 shows the results of a vibration test of the housing 120 while operating a bone conduction speaker 100 supplied in accordance with some exemplary embodiments of this application. In vibration testing, the physical quantities used to evaluate vibration magnitude or loudness may include, but are not limited to, vibration source speed, displacement, sound pressure level, etc. As an example, in the vibration test shown in FIG. 6, the acceleration level of the vibration source (unit: dB) is used as a physical quantity to evaluate vibration. In fig. 6, the solid line indicates a curve in which the vibration acceleration level of the bone conduction speaker 100 changes with the driving frequency f when the mass of the body 120 is m ₁ ; the dotted line indicates the curve in which the vibration acceleration level of the bone conduction speaker 100 changes with the driving frequency f after increasing the mass m ₁ of the housing 120 by 50%.

As can be seen from Fig. 6, the vibration acceleration level of the housing 120 depends on the frequency and mass. Relative to the initial body mass m ₁ , when the body mass of 120 m ₁ turns into 1.5 m ₁ , the level of body vibration acceleration does not decrease significantly only in the low frequency range below 160 Hz, in the middle and high frequency ranges it decreases by about 3-4 dB. That is, the amplitude of vibrations of the housing 120 decreases by 3-4 dB with an increase in the mass of the housing 120 by 0.5 times in the middle and high frequency ranges.

The above conclusions are based on the results obtained from speaker simulations. Within the human hearing range, in general, the range from 20 Hz to 150 Hz are low frequencies, the range from 150 Hz to 5 kHz are mid frequencies, the range from 5 kHz to 20 kHz are high frequencies, the range from 150 Hz up to 500 Hz - mid-low frequencies, range from 500 Hz to 5 kHz - high frequencies. For those skilled in the art, the above frequency band differences are only approximate ranges. The definitions of the above frequency ranges may vary depending on the industry, different application scenarios and different classification criteria. For example, in other application scenarios, low frequencies include the frequency range from 20 to 80 Hz, mid-bass frequencies include the frequency range from 80 Hz-160 Hz, mid frequencies include the frequency range from 160 Hz to 1280 Hz, mid-high frequencies include the frequency range 1280 Hz is 2560 Hz, and high frequencies are the frequency range from 2560 Hz to 20 kHz.

It should be clarified that although the previous description only shows the relationship between the volume produced by the bone conduction speaker and the mass of the body, the first speaker 310 in this application is not limited to bone conduction speakers. For example, in the case of air conduction speakers, the first speaker 310 still satisfies the above analysis.

As an example, in FIG. 7 is a design diagram of an electrodynamic speaker 500 provided in accordance with an embodiment of this application; The electrodynamic speaker shown in FIG. 7, Can be air conduction speaker. In particular, the electrodynamic speaker 500 may include a magnetic circuit assembly 520, a vibration assembly 530, and a support auxiliary assembly 510.

The support auxiliary assembly 510 may support the vibration assembly 530 and the magnetic circuit assembly 520. The support auxiliary assembly 510 may consist of an elastic member 511. The vibrating assembly 530 is attached to the support auxiliary assembly 510 by an elastic member 511.

Magnetic circuit assembly 520 may convert the electrical signal into excitation F. Excitation F may act on vibration assembly 530.

The vibration unit 530 can vibrate and produce sound waves under the action of excitation F.

Using dynamic analysis, it can be concluded that, along with the bone conduction speaker 100, the vibration amplitude of the vibration unit 530 in the electrodynamic dynamics 500 under the action of excitation F correlates with the equivalent mass m, excitation F, damping c and stiffness k of the vibration unit 530 Including, the greater the equivalent mass of the vibration unit 530, the smaller the amplitude of vibrations without changing other parameters. If other parameters do not change, the greater the excitation F, the greater the amplitude of oscillations. Details of the dynamic analysis process will not be given here.

From the above, it can be seen that the magnitude of the volume of the first sound wave 21 generated by the vibration of the first mechanical structure 311 correlates with the frequency of the first electrical signal 11 and the mass of the first mechanical structure 311. The greater the mass of the first mechanical structure 311, the lower the volume of the first sound wave 21.

Further in Fig. 2, a second speaker 320 is electrically coupled to a signal processing circuit 330. A second speaker 320 may receive a second electrical signal 12 from a signal processing circuit 330 and convert the second electrical signal 12 into a second sound wave 22. The second speaker 320 may be a power conversion device. In some embodiments, the second speaker 320 may convert the received electrical signal into mechanical vibration. Moreover, the second sound wave 22 is generated by mechanical vibrations. In some embodiments, the second speaker 320 may include a second mechanical structure 321 and a second driver 322. The design and function of the second mechanical structure 321 may be identical or similar to the design and function of the first mechanical structure 311; the design and function of the second driver 322 may be identical or similar to the design and function of the first driver 312. Details of the design and function of the second mechanical structure 321 and the second driver 322 will not be set forth herein.

Along with the first speaker 310, the magnitude of the volume of the second sound wave 22 generated by the vibration of the second mechanical structure 321 in the second speaker 320 correlates with the frequency of the second electrical signal 21 and the mass of the second mechanical structure 321. The greater the mass of the second mechanical structure 321, the lower the volume of the first sound wave 22.

Further in Fig. 1, in some embodiments, an accessory device 940 is mounted on one end of the first speaker 310. As an example, the accessory device 940 may include a function key mounted on a housing on one side of the bone conduction headset. As an example, accessory device 940 may include a headset microphone mounted on a housing on one side of the bone conduction headset. Said headset microphone may include, but is not limited to, a microphone base, a microphone arm, and elements such as a microphone. Adjusting the headset microphone improves the quality of the headset's bone conduction communication. Compared with the weight of the audio output device 300, attention must be paid to the weight of the additional equipment 940. Since the additional device 940 is located on the one-sided side of the audio output device 300 (that is, on the side of the first speaker 310), this results in the weight of the first mechanical structure 311 in the first speaker 310 is greater than the mass of the second mechanical structure 311 in the second speaker 310. For example, the mass of the housing with the bone conduction speaker on the side with the headset microphone is greater than the mass of the housing with the bone conduction speaker on the other side without the headset microphone.

From the previous description, it can be understood that without taking into account the difference in damping and stiffness, the mass of the first mechanical structure 311 is greater than the mass of the second mechanical structure 321 at the same electrical signal input, which causes the vibration amplitude of the first mechanical structure 311 to be less than the vibration amplitude of the second mechanical structure 321 Ignoring the difference between transmission medium and transmission distance, the volume of the first sound wave emitted by the first speaker 310 heard by the user will be less than the volume of the second sound wave emitted by the second speaker 320.

If the difference between the loudness of the first sound wave and the loudness of the second sound wave heard by the user (hereinafter referred to as the loudness difference) persists for a long time, the user's hearing will be damaged. (For example, when the difference in volume of the sound heard by both ears of the user is more than 3 dB over a long period of time, it may damage both of the user's ears.) In addition, the difference in volume between the first and second sound waves heard by the user may also result in a bias between the user's perceived phantom source and the actual imaginary source. Therefore, it is necessary to adjust the volume of the first and second sound waves so that the volume of the first sound wave and the second sound wave is as consistent as possible to avoid hearing damage caused by said volume difference as well as displacement of the imaginary source.

In fig. 8 is a diagram S200 of a volume control method provided in accordance with several embodiments of this application. Circuit S200 is used to adjust the volume of sound produced by the first speaker 310 and second speaker 320 of the audio output device 300. Circuit S200 is also used to adjust the apparent source of the audio output device 300 perceived by the user. In particular, the circuit S200 may include: S210, for obtaining a difference in volume of the first and second sound waves; and S220, for adjusting the difference in amplitude values of the first excitation and the second excitation.

S210, to obtain the difference in the volume of the first and second sound waves. In some embodiments, the difference in volume is greater than 3 dB.

S220, for adjusting the difference in amplitude values of the first excitation and the second excitation. From the previous description, it can be understood that the mass of the first mechanical structure is greater than the mass of the second mechanical structure, which leads to the fact that the amplitude of vibration of the first mechanical structure is less than the amplitude of vibration of the second mechanical structure, which in turn leads to the fact that the volume of the first sound wave is less, than the volume of the second sound wave. Thus, it is possible to adjust the amplitude of the first mechanical structure by adjusting the amplitude of the first drive; the amplitude of the second mechanical structure can be adjusted by adjusting the amplitude of the second drive; then corrects for differences in volume caused by differences in the mass of the first and second mechanical structures.

For better understanding, in the lower description of this application, F1 represents the magnitude of the first excitation, F2 represents the magnitude of the second excitation, M1 represents the mass of the first mechanical structure, M2 represents the mass of the second mechanical structure, S1 represents the cross-section of the first winding, S2 represents the cross-section windings of the second coil, in ρ1 - the resistivity of the winding of the first coil, in ρ2 - the resistivity of the second winding, in B1 - the magnetic field strength of the first magnetic part, in B2 - the magnetic field strength of the second magnetic part, in R1 - the resistance of the winding of the first coil (hereinafter the first resistance), in R2 - the resistance of the winding of the second coil (hereinafter referred to as the second resistance).

Using formulas (1) and (6), it adjusts the values of the first excitation F1 and/or the second excitation F2 so that the amplitude of vibrations X1 of the first mechanical structure 311 corresponds to the amplitude X2 of vibrations of the second mechanical structure 321, in turn, brings the volume of the first sound wave 21 into compliance with the volume of the second sound wave 22.

In some embodiments, by adjusting the winding diameter of the first coil and/or the winding diameter of the second coil, the first excitation F1 and the second excitation F2 are of different magnitudes, and in turn, matches the volume of the first sound wave 21 with the volume of the second sound wave 22. Thanks to M1 > M2, you can make S1 > S2 by increasing the winding diameter of the first coil and/or decreasing the winding diameter of the second coil. The first drive F1 produced by the first drive 312 according to formula (1) is greater than the second drive F2 produced by the second drive 422. According to formula (6), when the first drive F1 is greater than the second drive F2, can make X1 and X2 the same. So, the first sound wave 21 has the same power as the second sound wave 22, and the user hears the first sound wave 21 at the same volume as the second sound wave 22. Thus, the difference in volume caused by differences in mass has been corrected between the first mechanical structure 311 and the second mechanical structure 321 (M1>M2). In addition, it is possible to avoid displacement of the imaginary source due to differences in volume.

Next, the method of adjusting the volume by adjusting the diameter of the coil matches the output volume with the output volume, ensuring the overall size of the coil remains unchanged. Thus, the structure and dimensions of the elements of the audio output device can remain unchanged.

As an example, when headphones require a relatively high maximum volume, a bone conduction speaker on one side with an additional device uses a coil of thicker wire diameter than the speaker wire on the other side without an additional device. For example, the ratio of the diameters of the speaker coil wires with a thick wire on the side with an additional device to the speaker coil wire on the side without an additional device is not less than any of the following values, or a range between any two of them: 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 2.0.

As an example, when headphones require less power dissipation, a bone conduction speaker on one side without an additional device uses a coil of thinner wire diameter than the speaker wire on the other side with an additional device. As an example, the ratio of the diameters of the speaker coil wires with a thin wire on the side without an accessory to the speaker coil wire on the side with an accessory is not greater than any of the following values or a range between any two of them: 0.90, 0.91, 0. 92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99.

In addition, it is also possible to obtain the first excitation F1 and the second excitation F2 of different sizes by adjusting the resistivity of the first coil and/or the resistivity of the second coil, and in turn, adjusts the volume of the first sound wave 21 to the volume of the second sound wave 22. Thanks to M1>M2, by decreasing the resistivity of the first coil ρ1 and/or increasing the resistivity of the second coil ρ2, make ρ1< ρ2. As an example, a particularly specific winding material can be selected so that ρ1<ρ2. Without changing other independent variables, according to formula (1), the first drive F1 produced by the first drive 312 is greater than the second drive F2 produced by the second drive 422. According to formula (6), when the first drive F1 is greater than the second drive F2, can make X1 and X2 are the same. So, the first sound wave 21 has the same power as the second sound wave 22, and the user hears the first sound wave 21 at the same volume as the second sound wave 22. Thus, the difference in volume caused by differences in mass has been corrected between the first mechanical structure 311 and the second mechanical structure 321 (M1>M2). Additionally, imaginary source offset due to volume differences has been corrected.

In addition, it is also possible to obtain the first excitation F1 and the second excitation F2 of different sizes by adjusting the resistivity of the first magnetic part B1 and/or the resistivity of the second magnetic part B2, and in turn, brings the volume of the first sound wave 21 into line with the volume of the second sound wave 22. Due to M1>M2, it is possible to make B1>B2 by increasing the magnetic field strength B1 of the first magnetic piece and/or decreasing the magnetic field strength of the second magnetic piece B2. Without changing other independent variables, according to formula (1), the first drive F1 produced by the first drive 312 is greater than the second drive F2 produced by the second drive 422. According to formula (6), when the first drive F1 is greater than the second drive F2, can make X1 and X2 are the same. So, the first sound wave 21 has the same power as the second sound wave 22, and the user hears the first sound wave 21 at the same volume as the second sound wave 22. Thus, the difference in volume caused by differences in mass has been corrected between the first mechanical structure 311 and the second mechanical structure 321 (M1>M2). Additionally, imaginary source offset due to volume differences has been corrected.

In addition, it is also possible to make B1>B2 by increasing the size of the first magnetic part and/or decreasing the size of the second magnetic part.

For example, you can select a magnetic part from a material with different magnetic properties, so that B1>B2. For example, for the first magnetic part, a material with a stronger magnet is used; For the second magnetic part, a material with a weak magnet is used. In some embodiments, the remanent magnetic field of the first magnetic piece is greater than the remanent magnetic field of the second magnetic piece to give the strength of the magnetic field B1 generated by the first electromagnetic driver greater than the strength of the magnetic field B2 produced by the second electromagnetic driver. In some embodiments, the coercive force of the first magnetic piece is greater than the coercive force of the second magnetic piece to give the strength of the magnetic field B1 generated by the first electromagnetic driver greater than the strength of the magnetic field B2 created by the second electromagnetic driver. In some embodiments, the magnetic energy storage of the first magnetic piece is greater than the magnetic energy storage of the second magnetic piece to give the strength of the magnetic field B1 generated by the first electromagnetic driver greater than the strength of the magnetic field B2 created by the second electromagnetic driver.

In some embodiments, by adjusting the value of the first resistance R1 and/or the second resistance R2, obtaining the first excitation F1 and the second excitation F2 of different values, in turn, aligns the volume of the first sound wave 21 with the volume of the second sound wave 22. In this application the first resistance R1 means the total resistance of the first speaker, including the internal resistance of the first speaker and possible additional resistance; the second resistance R2 means the total resistance of the second speaker, including the internal resistance of the second speaker and possible additional resistance. Thanks to M1>M2, can make R1<R2 by decreasing the first resistance R1 and/or increasing the second resistance R2. Without changing other independent variables, according to formula (1), the first drive F1 produced by the first drive 312 is greater than the second drive F2 produced by the second drive 422. According to formula (6), when the first drive F1 is greater than the second drive F2, can make X1 and X2 are the same. So, the first sound wave 21 has the same power as the second sound wave 22, and the user hears the first sound wave 21 at the same volume as the second sound wave 22. Thus, the difference in volume caused by differences in mass has been corrected between the first mechanical structure 311 and the second mechanical structure 321 (M1>M2). As an example, when headphones do not have particularly stringent requirements for maximum volume and power dissipation, a bone conduction speaker on one side without an additional device (such as a headset microphone) is connected in series with the electrical resistance. As an example, the resistance of a series connection of bone conduction speakers on the side without an additional device is at least 1 ohm. It should be clarified that a series resistance is not necessarily a separate resistor element, and the same effect can be achieved by controlling the resistance of the wire used in the circuit (for example, an earphone wire mounted behind the ear).

It is also possible to make the first resistance R 1 smaller than the second resistance R2 by connecting a resistance in series outside the second coil (i.e. R1<R2), which in turn corrects the difference in volume caused by differences in the mass of the first mechanical structure 311 and the second mechanical structure 321. Further, the application of the series external resistance method does not require the addition of materials during the production and design process, which has less impact on production and design.

It is also possible to make the first resistance R1 smaller than the second resistance R2 by decreasing the resistance R1 of the first coil itself and/or increasing the resistance R2 of the second coil (i.e. R1<R2), which in turn corrects the difference in volume caused by the differences in the mass of the first mechanical structure 311 and the second mechanical structure 321. According to the formula R = ρL/S, in some embodiments it is possible, by decreasing the resistivity of the first coil and/or increasing the resistivity of the second coil, to make the resistance of the first coil less than the resistance of the second coil. In some embodiments, it is possible by increasing the winding length of the first coil and/or decreasing the winding length of the second coil to make the resistance of the first coil less than the resistance of the second coil. In some embodiments, it is possible by reducing the winding diameter of the first coil and/or increasing the winding diameter of the second coil to make the resistance of the first coil less than the resistance of the second coil. It should be explained that as the electrical resistivity, winding length, and/or winding diameter of the first and/or second coil increases and/or decreases, the mass of the first and/or second coil may also change. The mass of the first and second coils also affects the vibration of the first and second mechanical structure. Therefore, when adjusting parameters such as resistivity, winding length and/or winding diameter, it is necessary to take into account the influence of other parameters so that the vibration amplitude of the first mechanical structure 311 ultimately matches the vibration amplitude of the second mechanical structure 321.

According to formula (6), in some embodiments, it is also possible to obtain the first excitation F1 / second excitation F2 with different amplitude values by adjusting the amplitude values of the first electrical signal 11 and/or the second electrical signal 12, which in turn adjusts the volume of the first audio signal waves 21 in accordance with the volume of the second sound wave 22.

As an example, due to M1>M2 may set up a power amplification circuit in the signal processing circuit 330. For example, the power control circuit 335 may be a power amplification circuit. The power amplification circuit may amplify the first electrical signal 11 such that the power of the first electrical signal 11 is greater than the power of the second electrical signal 12. Thus, if the amplitude of the first electrical signal 11 is identical to the amplitude of the second electrical signal 12 without bypassing the power control circuit 335, the amplitude the first electrical signal 11, after passing through the power control circuit 335, will be greater than the amplitude of the second electrical signal 12. The first speaker 310 receives the amplified first electrical signal, such that the first drive F1 produced by the first speaker 310 will be greater than the second drive F2 generated by the second speaker 320 (ie F1>F2).

As an example, due to M1>M2 can set a power attenuation circuit in the signal processing circuit 330. For example, the power control circuit 335 can be a power attenuation circuit. The power attenuation circuit attenuates the second electrical signal 12. Thus, the amplitude of the first electrical signal 11 is greater than the amplitude of the second electrical signal 12. The second speaker 320 receives the reduced second electrical signal 12. Thus, if the amplitude of the first electrical signal 11 is identical to the amplitude of the second electrical signal 12 at without passing the power control circuit 335, then the second drive F2 generated by the second speaker 320 after passing the power control circuit 335 based on the reduced second electrical signal 12 will be smaller than the first drive F1 (ie, F1>F2). If other independent variables do not change, according to formula (6), the first excitation F1 is greater than the second excitation F2, which coordinates X1 with X2. So, the first sound wave 21 has the same power as the second sound wave 22, and the user hears the first sound wave 21 at the same volume as the second sound wave 22. Thus, the difference in volume caused by differences in mass has been corrected between the first mechanical structure 311 and the second mechanical structure 321 (M1>M2). As an example, it is also possible to adjust the audio signal gain from the bone conduction speaker on both sides of the bone conduction headset using the software of the chip in the bone conduction headphone so that the volume on both sides of the headset is the same.

Additionally, in some embodiments, it is possible to directly, by adjusting the mass of the first mechanical structure 311 and/or the second mechanical structure 321, match the mass of the first mechanical structure 311 with the mass of the second mechanical structure 321 to correct for differences in the volume of the first sound wave 21 and the second sound wave 22 caused by differences in mass. For example, a headset microphone, function keys, etc., are mounted on one side of the first speaker 310, which causes the mass of the first mechanical structure 311 to be greater than the mass of the second mechanical structure 321, and therefore may increase the mass of the second mechanical structure 321 to the same mass as the first mechanical structure 311, increasing the additional mass on one side of the second speaker 320. Thus, the first mechanical structure 311 and the second mechanical structure 321 have the same mass, and ultimately the first sound wave 21 has the same volume , like the second sound wave 22.

It should be clarified that the volume and power mentioned in the above solutions and/or embodiments for adjusting the volume refer to the volume and power of the sound emitted by the speaker in the earphone, and not the amount of electricity consumed by the earphone. The above-mentioned solutions and/or implementations for volume control are not unique. The above-mentioned solutions and/or embodiments for adjusting the volume may be used separately to adjust the volume at both ends of the audio output device 300. The above-mentioned solutions and/or embodiments for adjusting the volume may also be combined and coordinated to adjust the volume at both ends of the audio output device. 300. For example, you can simultaneously adjust quality and arousal. For example, when M1>M2, the combinations of “Increase the mass of the second mechanical structure 311”, “Increase the first excitation”, “Increase the diameter of the first coil”, etc. can be simultaneously used to match the volume of the first speaker 310 with the volume of the second speaker 320.

The above solutions and/or implementations for volume control have achieved good technical results in actual production. As an example, below are the test results of three headphone samples. Pattern 1: On the bone conduction speaker, the low volume side uses a thicker wire diameter coil, and the other side uses a normal coil; pattern 2: on the bone conduction speaker, the high volume side uses a thinner wire diameter coil, and the other side uses a normal coil; sample 3: a bone conduction speaker on the high volume side is connected in series to a resistance with a certain value. For all three samples, the same functional module is additionally installed on the side of the speaker with bone conduction, and on the other side without a functional module. Using a mobile phone to play a white noise signal, connect the sample headphones to be tested via Bluetooth, check the total current at the battery end of each headphone at the same volume. The test results are shown in Table 1. During the test, the output voltage at the end of the battery remained virtually unchanged (4.0-4.2 V).

Table 1. Total current at the end of the battery of headphone samples at the same volume

Based on the test results in Table 1, it is known that the total current at the end of the battery of three headphone samples with additional functional modules (samples 1, 2, 3) at the same sound volume increases compared to normal headphones. Of the three samples, sample 2 (the speaker on the high volume side uses a thinner wire diameter coil and the other uses a normal coil) has the lowest total current; sample 1 (the speaker on the low volume side uses a coil with a thicker wire diameter, and the other side uses a normal coil) has the highest total current. For sample 3 (the bone conduction speaker on the high volume side is connected in series with a resistance with a certain value), it only requires connecting one electrical resistance in series with the circuit board or applying another method to achieve the effect of series electrical resistance, in the production and design process there is no need to apply additional material, which has less impact on production and design.

In addition, battery life testing was carried out on different samples. Will test at the same listening volume (85dB), use a mobile phone to play a white noise signal, connect the sample headphones to be tested via Bluetooth, different sample headphones use batteries of the same capacity, batteries are fully charged at the start of the test, actual duration The service life of different samples is shown in Table 2.

Table 2. Battery life of headphone samples

Start time End time Duration Sample 1 9:58 12:02 2:04 Sample 2 13:47 16:05 2:18 Sample 3 17:47 20:10 2:23 Normal headphones 16:14 19:07 2:53

According to the test results given in Table 2, it is known that at the same sound volume, the batteries of three samples last significantly less than conventional samples, and sample 1 has the shortest service life, and sample 3 is slightly shorter than sample 2, but the differences between them are insignificant. The above results are consistent with previous battery current test results.

From the previous discussion, it is known that if the volume of the first sound wave 21 heard by the user is less than the volume of the second sound wave 22, it is possible to compensate for the difference in volume of the two headphones by adjusting the structural structure of the headphones. In addition, it can correct the difference in the volume of these headphones based on imaginary sources formed by the headphone.

An imaginary sound source is the point at which sound is reproduced from a sound source in the sound field, i.e. an imaginary sound source is the localization of the sound source. The user's brain determines the sound position of the target sound information (that is, the imaginary source perceived by the user) is shifted towards the side of the second sound wave 22 with a higher volume - that is, the side of the second speaker 320. In fact, the distance between the first speaker 310 and the second speaker 320 from the user can be considered the same, that is, the actual imaginary source of the target audio message 10 is in the middle (that is, directly in front or behind the user). That is, there is a shift between the user's perceived imaginary source and the actual imaginary source. The present application discloses a method for adjusting an imaginary source to make the imaginary source perceived by the user as close as possible to the actual source, thereby reducing the offset of the user's perceived imaginary source to the actual imaginary source. The imaginary source control method may be applied alone to the headphones described herein or in combination with the above loudness compensation circuits and/or embodiments.

In fig. 9 is a diagram S100 of an imaginary source adjustment method provided in accordance with several embodiments of this application. The circuit S100 is used to adjust the imaginary source produced by the first speaker 310 and the second speaker 320 of the audio output device 300. Specifically, the circuit S100 may include: S110, for obtaining a difference in volume of the first and second sound waves; S120, to adjust the time difference of the first sound wave and the second sound wave.

The "binaural effect" is an effect in which people determine the orientation of a sound based on volume differences, time differences, phase differences, and timbre differences between the two ears. Since there is a certain distance between the left and right ears, in addition to sound coming from directly in front and behind, the same sound coming from other directions reaches both ears at different volumes, times, phases and timbres, resulting in differences in volume, time, phase and timbre. As an example, if the sound source is to the right, then the sound should first reach the right ear and then the left. The more the sound is shifted to one side, the greater the time difference. As an example, if the sound source is located to the right, then the sound source is closer to the right ear than the left ear and reaches the right ear at a louder volume than the left ear. The more the sound is shifted to one side, the greater the difference in volume. As an example, sound travels as a wave, and the phase of the sound waves is different at different positions in space. Due to the spatial distance between the two ears, there may be a difference in the phase in which the sound wave reaches the two ears. The eardrum vibrates under the influence of sound waves. This oscillation phase difference also becomes a factor by which the user's brain determines the orientation of the sound source.

The human brain relies on the "binaural effect" to determine the location of the sound source (that is, the imaginary source).

If the left ear hears a sound first, then the listener’s brain perceives this sound from the left (from the side that hears the sound first), that is, the imaginary source perceived by the listener’s brain is shifted to the left side. And vice versa too. This phenomenon is called the time-difference effect of sound arrival between the two ears.

If the left ear hears a sound louder than the right, the listener's brain will think that the sound is coming from the left side, and vice versa. This phenomenon is called the “loudness difference” effect of sounds perceived by the right and left ears. The above displacement of the imaginary source caused by differences in the mass of the first and second mechanical structures can essentially also be understood as a “loudness difference” effect.

Thus, a “time difference” and/or a “phase difference” can be used to adjust the offset of the user-perceived imaginary source caused by the “loudness difference.”

S110, to obtain the difference in volume of the first and second sound waves. First, the difference in loudness of the first sound wave 21 and the second sound wave 22 is obtained. The displacement value of the imaginary source caused by the loudness difference can be obtained in accordance with the loudness difference. For example, the volume of the first sound wave 21 is less β than the volume of the second sound wave 22, then the apparent source perceived by the user is shifted δ from the centered position towards the second speaker 320.

S120, to adjust the time difference of the sound produced by the first and second sound waves.

In some embodiments, the displacement of the user-perceived imaginary source caused by differences in mass of the first mechanical structure 311 and the second mechanical structure can be adjusted by adjusting the difference in the timing of the sound produced by the first sound wave 21 and the second sound wave 22.

As an example, the volume of the first sound wave 21 is less than the volume of the second sound wave 22. When the audio output device 300 converts the target audio information 10 into the first sound wave 21, the first duration t1 is required; when the audio output device 300 converts the target audio information 10 into the second audio wave 22, a second duration t2 is required; and the first duration t1 is shorter than the second duration t2. Thus, for target audio information 10, the sound time of the first speaker 310 will be earlier than the sound time of the second speaker 320. In some embodiments, the sound time of the first speaker 310 is one time difference unit earlier than the sound time of the second speaker 320. In some embodiments, the difference is time does not exceed 3 ms. Specifically, the specified time difference can be any of the following values or between any two values: 0.1 ms, 0.2 ms, 0.3 ms, 0.4 ms, 0.5 ms, 0.6 ms, 0 ,7 ms, 0.8 ms, 0.9 ms, 1.0 ms, 1.1 ms, 1.2 ms, 1.3 ms, 1.4 ms, 1.5 ms, 1.6 ms, 1 ,7 ms, 1.8 ms, 1.9 ms, 2.0 ms, 2.1 ms, 2.2 ms, 2.3 ms, 2.4 ms, 2.5 ms, 2.6 ms, 2 .7 ms, 2.8 ms, 2.9 ms, 3.0 ms. It is assumed that the first sound wave 21 and the second sound wave 22 are in the same circumstances except for the timing of the sound. Given the same transmission media and distances, the time of the first sound wave 21 heard by the user's left ear will be earlier than the time of the second sound wave 22 heard by the right ear. By the binaural effect, the user's brain determines that the position of the source of the target sound information 10 is shifted towards the first sound wave 21 pronounced earlier - that is, to the left of the user. Thus, taking into account the rightward shift of the imaginary source caused by the volume of the first sound wave 21 being less than the volume of the second sound wave 22, the position of the source of the target audio information 10 heard by the end user (i.e., the user-perceived imaginary source) , will also be adjusted to the middle. In this way, the shift of the imaginary source to the right caused by the mass of the first mechanical structure 311 being greater than the mass of the second mechanical structure 321 can be solved.

In some embodiments, the position of the imaginary headphone source can be adjusted to control the time difference of the audio signal from the speakers on both sides (that is, the time difference between the right and left channels of the audio signal). For example, the position of the imaginary headphone source can be adjusted by controlling the time difference between the sound waves output from the speakers on both sides. For example, due to the action of the first speaker and the action of the second speaker, the first sound wave exiting the first speaker is earlier than the second sound wave exiting the second speaker. In some embodiments, the first sound wave is one unit of time difference earlier than the second sound wave. In some implementations, the time difference is less than 3 ms. Specifically, the specified time difference can be any of the following values or between any two values: 0.1 ms, 0.2 ms, 0.3 ms, 0.4 ms, 0.5 ms, 0.6 ms, 0 ,7 ms, 0.8 ms, 0.9 ms, 1.0 ms, 1.1 ms, 1.2 ms, 1.3 ms, 1.4 ms, 1.5 ms, 1.6 ms, 1 ,7 ms, 1.8 ms, 1.9 ms, 2.0 ms, 2.1 ms, 2.2 ms, 2.3 ms, 2.4 ms, 2.5 ms, 2.6 ms, 2 .7 ms, 2.8 ms, 2.9 ms, 3.0 ms. For example, the time difference could be 1.0 ms or just over 1.0 ms.

In some embodiments, the position of the imaginary headphone source may be adjusted to control the time difference of the audio signal input from the speakers on either side (i.e., the time difference between the right and left electrical signals). For example, due to the operation of the signal processing circuitry, a first electrical signal input to the first speaker is earlier than a second electrical signal input to the second speaker. In some embodiments, the first electrical signal is one time difference unit earlier than the second electrical signal. In some implementations, the time difference is less than 3 ms. Specifically, the specified time difference can be any of the following values or between any two values: 0.1 ms, 0.2 ms, 0.3 ms, 0.4 ms, 0.5 ms, 0.6 ms, 0 ,7 ms, 0.8 ms, 0.9 ms, 1.0 ms, 1.1 ms, 1.2 ms, 1.3 ms, 1.4 ms, 1.5 ms, 1.6 ms, 1 ,7 ms, 1.8 ms, 1.9 ms, 2.0 ms, 2.1 ms, 2.2 ms, 2.3 ms, 2.4 ms, 2.5 ms, 2.6 ms, 2 .7 ms, 2.8 ms, 2.9 ms, 3.0 ms. For example, the time difference could be 1.0 ms or just over 1.0 ms.

In addition, the offset value δ for the user-perceived imaginary source was obtained, and it was also possible to adjust the user-perceived imaginary source by adjusting the phase difference of the first sound wave 21 and the second sound wave 22 to center the user-perceived imaginary source. As an example, it is assumed that the phase of the first sound wave 21 should be greater than the phase of the second sound wave 22 by δw2, then the imaginary source is shifted in the direction of the first sound wave 21 by δ.

To cause the phase of the first sound wave 21 to be greater than the phase of the second sound wave 22 by δw2, a phase delay circuit may be installed in the signal processing circuit 330 and/or the first speaker 310 and/or the second speaker 320.

For example, it is possible to set the phase delay in the second speaker 320 so that the phase of the first sound wave 21 is greater than the phase of the second sound wave 22 by δw2. For example, signal processing circuitry 330 processes the target audio information 10 such that the generated first electrical signal 11 has the same phase as the second electrical signal 12. A phase delay circuit may be installed in the second speaker 320. The second speaker 320 may delay the phase of the second electrical signal 12 by δw2 and generate a second sound wave 22, the phase of which is also delayed by δw2. That is, ultimately, the phase of the first sound wave 21 is greater than the phase of the second sound wave 22 by δw2. Depending on the binaural effect, the imaginary source perceived by the user is shifted towards the first sound wave 21 with a larger phase. Thus, the displacement of the imaginary source in the direction of the second sound wave 22 caused by the mass m1 of the first mechanical structure 311 being greater than the mass m2 of the second mechanical structure 321 can be eliminated. Ultimately, the user perceives the imaginary source located at the center.

For example, it is also possible to set a phase delay circuit in the signal processing circuit 330 so that the phase of the first sound wave 21 is greater than the phase of the second sound wave 22 by δw2. For example, signal processing circuitry 330 may process target audio information 10 to obtain a first electrical signal 11 and a second electrical signal 12. The phase of the first electrical signal 11 is greater than the phase of the second electrical signal 12 by δw1. and δw1= δw2. The first speaker 310 will perform the same processing on the phase of the first electrical signal 11 that the phase of the second electrical signal 12 is processed by the second speaker 320 (e.g., the first speaker 310 does not process the phase of the first electrical signal 11; the second speaker 320 does not process the phase of the second electrical signal 12). Thus, ultimately, the phase of the first sound wave 21 generated by the first speaker 310 is greater than the phase of the second sound wave 22 generated by the second speaker 320 by δw2. Depending on the binaural effect, the imaginary source perceived by the user is shifted towards the first sound wave 21 with a larger phase. Thus, the displacement of the imaginary source in the direction of the second sound wave 22 caused by the mass m1 of the first mechanical structure 311 being greater than the mass m2 of the second mechanical structure 321 can be eliminated. Ultimately, the user perceives the imaginary source located at the center.

In some embodiments, the difference in volume between the first and second sound waves is less than 3 dB. Thus, can use the “time difference” and/or “phase difference” to adjust the offset of the user-perceived imaginary source caused by the “loudness difference”, on the one hand, adjusts the user-perceived imaginary source, and on the other hand, has no effect on user's hearing. This is because, adjusting the phase difference/time difference for the center position of the imaginary source is only to adjust the imaginary source perceived by the user, and does not change the volume of the first and second sound waves that the left and left ears actually hear. If the difference in the volume of sound waves heard by the left and right ears is too great, prolonged use may cause damage to both of the listener's ears.

The present application discloses a method for adjusting an imaginary source S100 and a method for adjusting the volume of S200. The imaginary source adjustment method S100 in this application includes: S110, to obtain a difference in the volume of the first and second sound waves; S120, to adjust the sound time difference of the first sound wave and the second sound wave. The volume control method S200 in this application includes: S210, for obtaining a difference in the volume of the first and second sound waves; and S220, for adjusting the difference in amplitude values of the first excitation and the second excitation. The imaginary source adjustment method S100 in this application corrects the displacement of the imaginary source perceived by the user caused by differences in the mass of the first and second mechanical structures by adjusting the time difference between the first and second sound waves. The volume control method S200 in this application corrects the difference in volume between the first and second speakers caused by differences in the mass of the first mechanical structure and the second mechanical structure by setting different coil resistivities, coil winding diameters, magnetic field intensity and/or resistance.

From the previous discussion, it is known that the volume of sound waves produced by a speaker is positively correlated with the amplitude of the mechanical structure of the speaker, provided that the difference between the transmission medium and the transmission distance is not taken into account. The greater the amplitude of the mechanical structure, the greater the volume of the sound waves. The amplitude of the mechanical structure is positively correlated with the excitation of the mechanical structure. For the same mechanical structures, the more excitation of the mechanical structure is motivated, the greater the amplitude of the mechanical structure.

In some embodiments, under the same excitation, the volume of the first sound wave produced by the first mechanical structure in the audio output device will be different from the volume of the second sound wave produced by the second mechanical structure. For example, in the audio output device 300 shown in FIG. 1, the accessory 940 is configured such that the mass of the first mechanical structure 311 is greater than the mass of the second mechanical structure 321 (ie, M).1>M2). According to formula (6), with the same excitation f, the vibration amplitude of the first mechanical structure is less than the vibration amplitude of the second mechanical structure without taking into account the difference between the transmission medium and the transmission distance, the volume of the first sound wave perceived by the user is less than the volume of the second sound wave. Of course, in some embodiments, there may be other reasons for the difference in the volume of the sound waves exiting the two ends of the audio output device, such as a difference in the quality of the two ends due to water getting into simple headphones, not equipped with a headset microphone, or other reasons. reasons, may ultimately also cause a difference in the volume of sound produced at both ends of the earphone. For understanding, the bone conduction speaker is described below as an example.

In practice, in order not to affect the user's experience of use, the volume of the sound heard by both ears of the user should be made as consistent as possible. From the above, it can be understood that the volume of sound waves produced by a speaker in a sound output device depends on the excitation generated from the electrical signals, the mass M of the mechanical structure creating the vibration, the damping C and the stiffness K of the vibration system.

For example, if we take a speaker with bone conduction 100 as an example, according to formula (6), the volume of sound waves produced by a speaker with bone conduction 100 is simultaneously influenced by the following parameters: excitation frequency f (size is 1/ω), excitation amplitude F0 f, mass m1 of the housing 120, mass m2 of the magnetic circuit 130, stiffness k1 of the vibration transmission plate 140 and damping c1 and stiffness k2 of the earphone 110 and damping c2. For example, if other parameters are kept unchanged, the excitation amplitude F ₀ f is positively correlated with the vibration amplitude X1 of the housing 120. The larger the excitation amplitude F ₀ f is, the greater the vibration amplitude X ₁ of the housing 120 is. For example, if other parameters are kept unchanged, the larger the mass m1 of the speaker housing 120 with bone conduction 100, the lower the oscillation amplitude, then the amplitude X ₁ of the housing 120. Thus, when the above parameters change, the amplitude X ₁ of the housing 120A changes along with it. The amplitude X ₁ of the housing 120, without taking into account the difference between the transmission medium and the transmission distance, is positively correlated with the loudness of the sound waves generated by the vibration of the housing 120. The larger the amplitude X ₁ , the louder the sound wave; the smaller the amplitude X ₁ , the lower the volume of the sound wave.

Thus, if the excitation mass F and the mechanical structure mass M can be intelligently balanced, the desired vibration amplitude X can be obtained. Even if there are differences in the quality of the mechanical structure at both ends of the audio output device (for example, a headset microphone mounted on one side of the earpiece with bone conduction) it is also possible to make the same volume output at both ends of the audio output device.

Therefore, the present application also discloses an audio output device. The audio output device may include, but is not limited to, headphones, hearing aids, helmets, etc. Headphones may include, but are not limited to, wired headphones, wireless headphones, Bluetooth headsets, and so on. Specifically, the audio output device may include a first speaker, a second speaker, and signal processing circuitry.

The signal processing circuitry may receive target audio information, process the target audio information, and generate a first electrical signal and a second electrical signal.

The first speaker is electrically connected to the signal processing circuitry. The first speaker may receive a first electrical signal from the signal processing circuitry and convert the first electrical signal into a first sound wave. In some embodiments, the first speaker includes a first bone conduction speaker and the first sound wave includes a first bone conduction sound. In some embodiments, the first speaker may convert the received first electrical signal into mechanical vibration. Moreover, the first sound wave is created by mechanical vibrations. In some embodiments, the first speaker may include a first mechanical structure and a first drive device. The first drive device generates a first drive based on the first electrical signal. The first excitation, as an external force, causes the first mechanical structure to vibrate, and subsequently the first sound wave is created by the first mechanical structure.

The second speaker is electrically connected to the signal processing circuitry. The second speaker may receive a second electrical signal from the signal processing circuitry and convert the second electrical signal into a second sound wave. In some embodiments, the second speaker includes a second bone conduction speaker and the second sound wave includes a second bone conduction sound. In some embodiments, the second speaker may convert the received second electrical signal into mechanical vibration. Moreover, the second sound wave is created by mechanical vibrations. In some embodiments, the second speaker may include a second mechanical structure and a second drive device. The second drive device generates a second drive based on the second electrical signal. The second excitation, as an external force, causes the second mechanical structure to vibrate, and subsequently a second sound wave is created by the second mechanical structure.

In some embodiments, electromagnetic drivers may be adopted for the first and second drive devices. The size of the first excitation and the size of the second excitation can be obtained by calculating using formula (1); the vibration process of the first and second mechanical structures can be represented by formula (6).

For better description, in the lower description of this application, F1 represents the magnitude of the first excitation, F2 represents the magnitude of the second excitation, M1 represents the mass of the first mechanical structure, M2 represents the mass of the second mechanical structure, S1 represents the cross-section of the first winding, S2 represents the cross-section windings of the second coil, in ρ1 - the resistivity of the winding of the first coil, in ρ2 - the resistivity of the second winding, in B1 - the magnetic field strength of the first magnetic part, in B2 - the magnetic field strength of the second magnetic part, in R1 - the resistance of the winding of the first coil (hereinafter the first resistance), in R2 - the resistance of the winding of the second coil (hereinafter referred to as the second resistance), in X1 - the amplitude of oscillation of the first mechanical structure, in X2 - the amplitude of oscillation of the second mechanical structure.

For the same excitation, the first mechanical structure produces a volume less than the second mechanical structure. As an example, in some embodiments, the mass M1 of the first mechanical structure is greater than the mass M2 of the second mechanical structure, such that the loudness of the first mechanical structure causing the first mechanical structure to oscillate under the same excitation is less than the loudness of the second sound wave produced by the second mechanical structure to oscillate . According to formulas (1) and (6), it is assumed that the first and second electrical signals are identical (U)1= U2), and, in addition, the first and second exciters are identical (i.e. B1=B2, S1=S2 , ρ1=ρ2, R1=R2), without taking into account differences in damping and stiffness (i.e. C1=C2, K1=K2), then using formulas (1) and (6) it can be obtained that the first excitation F1 and the second excitation F2 are the same (F1= F2). Based on the above assumptions, since M1>M2, from the dependence of mass on amplitude, it is known that the vibration amplitude of the first mechanical structure is less than the vibration amplitude of the second mechanical structure. Given the same transmission medium and transmission distance, the volume of the sound wave emanating from the first speaker heard by the user will be less than the volume of the sound wave emanating from the second speaker. The volume of the first sound wave is the same as the volume of the second sound wave.

Below, the first sound wave heard by the user's left ear and the second sound wave heard by the user's right ear are used as an example. It is generally required that the volume of the first sound wave heard by the user's left ear be as similar as possible to the volume of the second sound wave heard by the right ear to avoid damage to both ears due to the difference in volume. That is, with the same transmission distance and transmission medium, the amplitude of vibration of the first mechanical structure will correspond as much as possible to the amplitude of vibration of the second mechanical structure.

In some embodiments, the diameter of the first coil winding is greater than the diameter of the second winding, that is, S1 > S2. In accordance with formulas (1) and (6), the first excitation F1 produced by the first exciting device is greater than the second excitation F2 produced by the second exciting device, thus, X1 can be matched with X2. So, the first sound wave has the same power as the second sound wave, and the user hears the first sound wave at the same volume as the second sound wave. Thus, the difference in volume caused by the difference in mass between the first mechanical structure and the second mechanical structure (M1>M2) has been corrected.

In some embodiments, the electrical resistivity of the first coil is less than the electrical resistivity of the second coil, i.e. ρ1<ρ2. In accordance with formulas (1) and (6), the first excitation F1 produced by the first exciting device is greater than the second excitation F2 produced by the second exciting device, X1 can be coordinated with X2. So, the first sound wave has the same power as the second sound wave, and the user hears the first sound wave at the same volume as the second sound wave. Thus, the difference in volume caused by the difference in mass between the first mechanical structure and the second mechanical structure has been corrected.

In some embodiments, at the same input current, the magnetic field strength B1 produced by the first electromagnetic excitation device is greater than the magnetic field strength B2 produced by the second electromagnetic excitation device. In accordance with formulas (1) and (6), the first excitation F1 produced by the first exciting device is greater than the second excitation F2 produced by the second exciting device, X1 can be coordinated with X2. So, the first sound wave has the same power as the second sound wave, and the user hears the first sound wave at the same volume as the second sound wave. Thus, the difference in volume caused by the difference in mass between the first mechanical structure and the second mechanical structure has been corrected. In some embodiments, the remanent magnetic field of the first magnetic piece is greater than the remanent magnetic field of the second magnetic piece to give a magnetic field strength B1 generated by the first electromagnetic driver greater than a magnetic field strength B2 produced by the second electromagnetic driver. In some embodiments, the coercive force of the first magnetic piece is greater than the coercive force of the second magnetic piece to give the strength of the magnetic field B1 generated by the first electromagnetic driver greater than the strength of the magnetic field B2 created by the second electromagnetic driver. In some embodiments, the magnetic energy accumulation of the first magnetic piece is greater than the magnetic energy accumulation of the second magnetic piece to give the strength of the magnetic field B1 generated by the first electromagnetic driver greater than the strength of the magnetic field B2 created by the second electromagnetic driver.

In some embodiments, the first resistance R1 is less than the second resistance R2. In accordance with formulas (1) and (6), the first excitation F1 produced by the first exciting device is greater than the second excitation F2 produced by the second exciting device, X1 can be coordinated with X2. So, the first sound wave has the same power as the second sound wave, and the user hears the first sound wave at the same volume as the second sound wave. Thus, the difference in volume caused by the difference in mass between the first mechanical structure and the second mechanical structure has been corrected.

In some embodiments, it is possible to make the first resistance R1 smaller than the second resistance R2 by connecting a resistance in series outside the second coil, which in turn corrects the difference in volume caused by differences in mass of the first mechanical structure and the second mechanical structure.

In some embodiments, it is possible to make the first resistance R1 smaller than the second resistance R2 by decreasing the resistance R1 of the first coil itself and/or increasing the resistance R2 of the second coil, which in turn corrects the difference in volume caused by differences in mass of the first mechanical structure and the second mechanical designs.

According to the formula R = ρL/S, in some embodiments it is possible by increasing the resistivity of the first coil and/or decreasing the resistivity of the second coil to make the resistance of the first coil less than the resistance of the second coil.

According to the formula R = ρL/S, in some embodiments it is possible by increasing the winding length of the first coil and/or decreasing the winding length of the second coil to make the resistance of the first coil less than the resistance of the second coil.

According to the formula R = ρL/S, in some embodiments it is possible by reducing the winding diameter of the first coil and/or increasing the winding diameter of the second coil to make the resistance of the first coil less than the resistance of the second coil.

It should be explained that as the electrical resistivity, winding length, and/or winding diameter of the first and/or second coil increases and/or decreases, the mass of the first and/or second coil may also change. The mass of the coils also affects the vibration of the first mechanical structure. Therefore, when adjusting parameters such as resistivity, winding length and/or winding diameter, it is necessary to take into account the influence of other parameters so that the vibration amplitude of the first mechanical structure ultimately matches the vibration amplitude of the second mechanical structure.

In some embodiments, a power amplification circuit may be installed in the audio output device. A power amplification circuit may be installed between the first speaker and the signal processing circuit. The first electrical signal output by the signal processing circuit passes through a power amplification circuit. The power amplification circuit amplifies the first electrical signal and outputs it to the first speaker. the first speaker receives the amplified first electrical signal. Thus, the first excitation F1 produced by the first speaker will be greater than the second excitation F2 generated by the second speaker (ie F1 > F2). According to formula (6), when the first excitation F1 is greater than the second excitation F2, so that X1 can be matched with X2. So, the first sound wave has the same power as the second sound wave, and the user hears the first sound wave at the same volume as the second sound wave. Thus, the difference in volume caused by the difference in mass between the first mechanical structure and the second mechanical structure has been corrected.

In some embodiments, a power attenuation circuit may be installed in the audio output device. A power attenuation circuit may be installed between the second speaker and the signal processing circuitry. The second electrical signal output from the signal processing circuit passes through a power attenuation circuit. The power attenuation circuit attenuates the second electrical signal and outputs it to the second speaker. the second speaker receives the reduced second electrical signal Thus, the second excitation F2 generated by the second speaker will be less than the first excitation F1 generated by the second speaker (i.e. F1>F2) According to formula (6), when the first excitation F1 is greater than the second excitation F2, so that X1 can be coordinated with X2. So, the first sound wave has the same power as the second sound wave, and the user hears the first sound wave at the same volume as the second sound wave. Thus, the difference in volume caused by the difference in mass between the first mechanical structure and the second mechanical structure has been corrected.

According to the previous description, when a difference in volume occurs on the two sides of the headphones, a displacement of the imaginary source perceived by the user occurs. Therefore, it is necessary to intelligently design the audio output device so that the imaginary source produced by the audio output device is as little biased as possible.

Therefore, the present application also discloses an audio output device. The audio output device may include, but is not limited to, headphones, hearing aids, helmets, etc. Headphones may include, but are not limited to, wired headphones, wireless headphones, Bluetooth headsets, and so on. Specifically, the audio output device may include a first speaker, a second speaker, and signal processing circuitry.

The signal processing circuitry may receive target audio information, process the target audio information, and generate a first electrical signal and a second electrical signal.

The first speaker is electrically connected to the signal processing circuitry. The first speaker may receive a first electrical signal from the signal processing circuitry and convert the first electrical signal into a first sound wave. In some embodiments, the first speaker includes a first bone conduction speaker and the first sound wave includes a first bone conduction sound. In some embodiments, the first speaker may convert the received first electrical signal into mechanical vibration. Moreover, the first sound wave is created by mechanical vibrations. In some embodiments, the first speaker may include a first mechanical structure and a first drive device. The first drive device generates a first drive based on the first electrical signal. The first excitation, as an external force, causes the first mechanical structure to vibrate, and subsequently the first sound wave is created by the first mechanical structure.

The second speaker is electrically connected to the signal processing circuitry. The second speaker may receive a second electrical signal from the signal processing circuitry and convert the second electrical signal into a second sound wave. In some embodiments, the second speaker includes a second bone conduction speaker and the second sound wave includes a second bone conduction sound. In some embodiments, the second speaker may convert the received second electrical signal into mechanical vibration. Moreover, the second sound wave is created by mechanical vibrations. In some embodiments, the second speaker may include a second mechanical structure and a second drive device. The second drive device generates a second drive based on the second electrical signal. The second excitation, as an external force, causes the second mechanical structure to vibrate, and subsequently a second sound wave is created by the second mechanical structure.

In some embodiments, electromagnetic drivers may be adopted for the first and second drive devices. The size of the first excitation and the size of the second excitation can be obtained by calculating using formula (1); the vibration process of the first and second mechanical structures can be represented by formula (6).

For better description in the lower description of this application, F1 represents the magnitude of the first excitation, F2 is the magnitude of the second excitation, M1 is the mass of the first mechanical structure, M2 is the mass of the second mechanical structure, S1 is the winding section of the first coil, S2 is the winding section of the second coil, ρ1 - resistivity of the winding of the first coil, ρ2 - resistivity of the winding of the second coil, B1 - magnetic field strength of the first magnetic part, B2 - magnetic field strength of the second magnetic part, R1 - resistance of the winding of the first coil (hereinafter referred to as the first resistance), R2 - resistance of the second winding coils (hereinafter referred to as the second resistance), X1 is the oscillation amplitude of the first mechanical structure, X2 is the oscillation amplitude of the second mechanical structure.

When input electrical signals are of the same amplitude and frequency, the volume of the sound wave produced by the first speaker is less than the volume of the sound wave produced by the second speaker. As an example, in some embodiments, the mass of the first mechanical structure M1 is greater than the mass of the second mechanical structure M2, resulting in the fact that, when input electrical signals are of the same amplitude and frequency, the volume of the sound wave produced by the first speaker is less than the volume of the sound wave, produced by the second speaker. According to formulas (1) and (6), assuming that the amplitude and frequency of the first and second electrical signals are identical (i.e. U1= U2), and that the first and second exciters are identical (i.e. B1= B2, S1= S2, ρ1= ρ2, R1= R2), without taking into account differences in damping and stiffness (i.e. C1=C2, K1=K2), using formulas (1) and (6) it can be obtained that the first excitation F1 and the second excitation F2 are the same (F1= F2). Based on the above assumptions, since M1>M2, which can be known from the mass-amplitude relationship, the vibration amplitude of the first mechanical structure is less than the vibration amplitude of the second mechanical structure. Given the same transmission medium and transmission distance, the volume of the sound wave emanating from the first speaker heard by the user will be less than the volume of the sound wave emanating from the second speaker. As an example, the difference between the volume of the first sound wave and the volume of the second sound wave does not exceed 3 dB when an electrical signal of the same amplitude and frequency is input.

For better description, the lower description of the present application takes as an example the transmission of the first sound wave to the left ear of the user, the transmission of the second sound wave to the right ear of the user to describe the user's perception of the target audio information. It is assumed that the first sound wave and the second sound wave are in the same circumstances, except for the volume, according to the binaural effect, the volume of the first sound wave heard by the user's left ear is less than the volume of the second sound wave heard by the user's right ear, then the brain The user determines that the sound position of the target sound information (that is, the imaginary source perceived by the user) is shifted to the right - that is, towards the second sound wave with higher volume.

Thus, according to the binaural effect, it can eliminate the displacement of the user's perceived imaginary source caused by "loudness difference" by taking advantage of "phase difference" and/or "time difference".

In some embodiments, when audio output device 300 converts target audio information 10 into first audio wave 21, a first duration t1 is required; converts the target audio information 10 into a second audio wave 22, a second duration t2 is required; and the first duration t1 is shorter than the second duration t2 by the time difference δt. Thus, for target audio information 10, the sound time of the first speaker 310 will be earlier than the sound time of the second speaker 320 by the time difference δt. In some implementations, the time difference δt is less than 3 ms. In particular, the specified time difference δt can be any of the following values or between any two values: 0.1 ms, 0.2 ms, 0.3 ms, 0.4 ms, 0.5 ms, 0.6 ms, 0.7 ms, 0.8 ms, 0.9 ms, 1.0 ms, 1.1 ms, 1.2 ms, 1.3 ms, 1.4 ms, 1.5 ms, 1.6 ms, 1.7 ms, 1.8 ms, 1.9 ms, 2.0 ms, 2.1 ms, 2.2 ms, 2.3 ms, 2.4 ms, 2.5 ms, 2.6 ms, 2.7 ms, 2.8 ms, 2.9 ms, 3.0 ms. For example, the time difference δt could be 1.0 ms or just over 1.0 ms. It is assumed that the first sound wave 21 and the second sound wave 22 are in the same circumstances except for the timing of the sound. Given the same transmission media and distances, the time of the first sound wave 21 heard by the user's left ear will be earlier than the time of the second sound wave 22 heard by the right ear. According to the binaural effect, the position of the source (that is, the imaginary source perceived by the user) of the target audio information 10 heard by the user is corrected.

In some embodiments, the time difference occurs as the first electrical signal is converted to a first sound wave by the first speaker and the second electrical signal is converted to a second sound wave by the second speaker. For example, it is possible to install a timing advance circuit in the first speaker and/or a timing delay circuit in the second speaker such that the first sound wave exiting the first speaker is earlier than the second sound wave exiting the second speaker. In some embodiments, the first sound wave is one unit time difference δt earlier than the second sound wave.

In some embodiments, a time difference occurs when the audio output device converts the target audio information into the first and second electrical signals. For example, it is possible to set the timing circuit in the signal processing circuit so that the first electrical signal supplied to the first speaker is earlier than the second electrical signal supplied to the second speaker. In some embodiments, the first electrical signal is one unit time difference δt earlier than the second electrical signal.

In some embodiments, there is a first phase difference δw1 between the second and first sound waves. In some embodiments, the phase of the first sound wave is greater than the phase of the second sound wave by δw1. It is assumed that the first sound wave and the second sound wave are in the same circumstances, except for the phases, by the binaural effect the user's brain determines that the position of the source of the target sound information (i.e. the imaginary source perceived by the user) is shifted towards the first sound wave with a larger phase - that is, to the left of the user. Thus, taking into account the rightward shift of the imaginary source caused by the volume of the first sound wave being less than the volume of the second sound wave, ultimately the position of the source of the target sound information heard by the user will be adjusted to the middle. In this way, the displacement of the imaginary source caused by the mass of the first mechanical structure being greater than the mass of the second mechanical structure can be solved.

In some embodiments, the phase of the second electrical signal is identical to the phase of the first electrical signal. As an example, a signal processing circuit processes target audio information so that the phase of the first electrical signal generated is identical to the phase of the second electrical signal. Moreover, a phase delay circuit can be installed in the second speaker. The phase delay circuit can delay the phase of the second electrical signal by δw1 and generates a second sound wave whose phase is also delayed by δw1. Thus, the phase of the first sound wave is greater than the phase of the second sound wave by δw1. In this way, the displacement of the imaginary source caused by the mass of the first mechanical structure being greater than the mass of the second mechanical structure can be solved.

In some embodiments, there is a second phase difference δw2 between the second and first electrical signals; and the second phase difference δw2 is matched with the first phase δw1. As an example, a phase delay circuit may be installed in the signal processing circuit. The signal processing circuitry may process the target audio information to obtain a first electrical signal and a second electrical signal. In addition, there is a second phase difference δw2 between the first and second electrical signals. For example, the phase of the first electrical signal is greater than the phase of the second electrical signal by δw2. The first and second speakers do not change the phase of the first electrical signal and the phase of the second electrical signal, such that the first sound wave produced by the first speaker is greater than the phase of the second sound wave produced by the second speaker by δw2. In this case, δw2 is identical to δw1, that is, ultimately, the phase of the first sound wave is greater than the phase of the second sound wave by δw1. In this way, it is also possible to solve the displacement of the imaginary source caused by the mass of the first mechanical structure being greater than the mass of the second mechanical structure.

Thus, for the target audio information, the sound time of the first speaker will be earlier than the sound time of the second speaker. It is assumed that the first sound wave and the second sound wave are in the same circumstances, except for the time of pronunciation of the sound. Given the same transmission media and distances, the time of the first sound wave heard by the user's left ear will be earlier than the time of the second sound wave heard by the right ear. Based on the binaural effect, the user's brain determines that the position of the source of the target sound information is shifted towards the first sound wave pronounced earlier - that is, to the left of the user. Thus, given the rightward shift of the imaginary source caused by the volume of the first sound wave being less than the loudness of the second sound wave, the source position of the target audio information heard by the end user (i.e., the user's perceived imaginary source) will also be adjusted to the middle. In this way, the rightward displacement of the imaginary source caused by the mass of the first mechanical structure being greater than the mass of the second mechanical structure can be solved.

The present application discloses a method for adjusting an imaginary source S100, a method for adjusting the volume of S200, and 2 kinds of audio output device. The imaginary source adjustment method S100 in this application includes: S110, to obtain a difference in the volume of the first and second sound waves; S120, to adjust the sound time difference of the first sound wave and the second sound wave. The volume control method S200 in this application includes: S210, for obtaining a difference in the volume of the first and second sound waves; and S220, for adjusting the difference in amplitude values of the first excitation and the second excitation. The sound output device and the imaginary source adjustment method S100 in this application correct the displacement of the imaginary source perceived by the user caused by differences in mass of the first and second mechanical structures by adjusting the time difference between the first and second sound waves. The audio output device and volume control method in this application corrects the difference in volume between left and right speakers caused by differences in the mass of the first mechanical structure and the second mechanical structure by setting different coil resistivities, coil winding diameters, magnetic field intensity and/or resistance .

It should be clarified that the transmission medium of the first and/or second sound wave specified in this application does not limit the scope of this application. The first and/or second sound wave described herein may be transmitted through a solid body (eg, a skeleton) as well as through a gas (eg, air). In some embodiments, the transmission medium may include one or a combination of air and skeleton.

It should be explained that during design and production, the volume control method, the imaginary source control method, and also the sound output device can be used together to achieve the desired control effect. For example, in some embodiments, the imaginary source output by the audio output device may be separately adjusted by the imaginary source adjustment method S100. For example, in some embodiments, simultaneously adjust the imaginary source and the volume of the sound output by the audio output device using the imaginary source adjustment method S100 and the volume adjustment method S200.

For example, you can adjust quality and arousal at the same time. For example, when M1>M2, the options "Increase the mass of the second mechanical structure 311", "Increase the first excitation", "Increase the diameter of the first coil", etc. can be simultaneously used to match the volume of the first speaker 310 with the volume of the second speaker 320.

For example, when M1 > M2, the options "Increase the mass of the second mechanical structure 311", "Increase the first excitation", "Decrease the diameter of the second coil", etc. can be simultaneously used to maintain differences in the volume of the first speaker 310 and the volume of the second speaker 320 in the area of difference in target loudness; then adjust the imaginary source by adjusting the phase difference.

It should be made clear that the statement of making the volume of the first speaker and the volume of the second speaker "matched" or "identical" is merely required for analysis purposes and does not limit the scope of this application. The statement of making the volume of the first speaker and the volume of the second speaker "matched" or "identical" can also be understood as keeping the difference in the volume of the first speaker and the second speaker in the realm of the difference in the target volume.

It should be clarified that the statement that making an imaginary source output by the audio output device “in the middle” is only required for analysis does not limit the scope of protection of this application. The statement about making the imaginary source “in the middle” can also be understood as keeping the imaginary source in the sphere of the target localization.

Thus, having become familiar with the details of the present invention, those skilled in the art will understand that the above detailed description of the invention can only be presented by way of example and is not intended to limit the scope of the invention. Although not expressly stated herein, those skilled in the art will understand that this application is intended to cover various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements and modifications are included in this application and do not depart from the spirit and scope of the illustrative embodiments of this invention.

The terms used herein are used only for the purpose of describing a particular embodiment and do not limit the scope of the present invention. For example, unless the context clearly indicates otherwise, the singular forms "one, one, one", "said", "given, this" used herein may also include plural forms. The terms “comprises,” “including,” “includes,” and/or “including” as used in the specification of this invention indicate the presence of specified properties, integers, steps, operations, elements, and/or components, but do not exclude the presence or addition of one or more other properties, integers, steps, operations, elements, components and/or groups thereof. When used in the description of this invention, the term "A is above B" can mean that A is directly adjacent to B (above or below), or that A is indirectly adjacent to B (that is, there may be something else between A and B) ; the term "A is in B" can mean that A is in B either completely or partially.

In addition, certain terms have been used to describe embodiments of this invention. For example, “one embodiment,” “an embodiment,” and/or “certain embodiments” means that particular features, structures, or characteristics described in combination with the embodiment may be included in at least one embodiment of the present invention. Therefore, it may be emphasized and understood that two or more references to “an embodiment,” “one embodiment,” or “an alternative implementation” in different parts of the specification of this invention do not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics may be suitably combined in one or more embodiments of the present invention.

It should be understood that to assist in understanding any feature in the above description of the invention and for the purpose of simplifying the invention, various features may sometimes be combined in a single embodiment, drawings or description. Alternatively, this application distributes various features across multiple embodiments of this invention. However, this does not mean that a combination of these characteristics is necessary; Upon reviewing the present invention, those skilled in the art may well be able to highlight certain characteristics as a distinct embodiment for understanding. In other words, embodiments of the present invention can also be understood as an integration of multiple secondary embodiments. It is also true that each secondary embodiment contains less than all the features of the one embodiment listed above.

In some embodiments, numbers expressing quantities or properties used to describe and claim certain embodiments of the application should be understood as modified in some cases by the term “about,” “approximately,” or “substantially.” For example, “about,” “approximately,” or “substantially” may indicate a deviation of ±20% from the specification unless otherwise noted. Therefore, in some embodiments, the numerical parameters given in the written description and the accompanying claims are approximate values that may vary depending on the properties to be obtained in a particular embodiment. In some implementations, numeric parameters should be interpreted based on the number of significant digits specified and by applying normal rounding techniques. Although the numerical range and parameters defining the broad applicability of some of the embodiments are approximate, the numerical values shown in the specific examples are stated as accurately as practicable.

Each of the patents, patent applications, patent application publications, and other materials, such as articles, books, specifications, publications, documents, things, and/or the like, referred to herein are incorporated herein by this reference in their entirety for all purposes, except for any prosecution history related thereto, or if they are inconsistent or inconsistent herewith, or if they may limit the broadest application of the claims now or later in connection herewith. By way of example, in the event of any inconsistency or conflict between the descriptions, definition and/or use of a term associated with any included material and a term associated herein, the description, definition and/or use of a term herein shall control.

In conclusion, it should be understood that the embodiments for the application specified herein illustrate the principles of the embodiments. Other modifications that can be used may be included in the scope of application. Thus, by way of example, and not by way of limitation, alternative configurations of embodiments may be used in accordance with the methods set forth herein. Those skilled in the art may use alternative configurations in accordance with the embodiment in this application to implement the invention in this invention. Accordingly, embodiments of the present application are not limited to what is specifically stated and described.

Claims (47)

1. An audio output device containing: a signal processing circuit for generating, in operation, a first electrical signal and a second electrical signal based on the target audio information; a first speaker electrically coupled to the signal processing circuit for operatively receiving a first electrical signal from the signal processing circuit and converting the first electrical signal into a first sound wave; And a second speaker electrically coupled to the signal processing circuitry for operatively receiving a second electrical signal from the signal processing circuitry and converting the second electrical signal into a second sound wave, wherein operatively the audio output device is configured to convert the target audio information into a first audio wave during the first duration and input the first audio to one ear of the user, the audio output device is configured to convert the target audio information into a second audio wave for a second duration and output the second audio to the user's other ear, Moreover, the first duration is shorter than the second duration by the time difference. 2. The audio output device according to claim 1, wherein the volume of the sound wave output by the first speaker is less than the volume of the sound wave output by the second speaker when the input electrical signals are of the same amplitude and frequency. 3. The audio output device according to claim 2, in which, for input electrical signals with the same amplitude and frequency, the difference between the volume of the first sound wave and the volume of the second sound wave does not exceed 3 dB, or The time difference does not exceed 3 ms. 4. The audio output device according to claim 2, in which the first speaker is configured to generate a first sound wave by energizing the first mechanical structure; A the second speaker is configured to generate a second sound wave by energizing the second mechanical structure, wherein the mass of the first mechanical structure is greater than the mass of the second mechanical structure, such that when input electrical signals are of the same amplitude and frequency, the volume of the sound wave output by the first speaker is less than the volume of the sound wave output by the second speaker. 5. The audio output device according to claim 2, in which the first speaker includes at least one of a first bone conduction speaker and a first air conduction speaker; A the second speaker includes at least one of a second bone conduction speaker and a second air conduction speaker. 6. The audio output device according to claim 1, wherein the time difference occurs during the process of the audio output device converting the target audio information into the first electrical signal and the second electrical signal. 7. The audio output device of claim 1, wherein the time difference occurs in the process of the first speaker converting the first electrical signal into a first sound wave and the second speaker converting the second electrical signal into a second sound wave. 8. Audio output device containing: a signal processing circuit for generating, in operation, a first electrical signal and a second electrical signal based on the target audio information; a first speaker electrically coupled to the signal processing circuit for operatively receiving a first electrical signal from the signal processing circuit and converting the first electrical signal into a first drive driving the first mechanical structure to generate a first sound wave; And a second speaker electrically coupled to the signal processing circuitry for operatively receiving a second electrical signal from the signal processing circuitry and converting the second electrical signal into a second drive driving the second mechanical structure to generate a second sound wave, wherein the volume of the first sound wave is identical to the volume of the second sound wave; And under the same excitation, the sound volume generated by the first mechanical structure is less than the sound volume generated by the second mechanical structure. 9. The audio output device of claim 8, wherein the mass of the first mechanical structure is greater than the mass of the second mechanical structure such that the volume of sound generated by the first mechanical structure is less than the volume of sound generated by the second mechanical structure. 10. The audio output device of claim 9, wherein the first speaker includes at least one of a first bone conduction speaker and a first air conduction speaker; A the second speaker includes at least one of a second bone conduction speaker and a second air conduction speaker. 11. The audio output device according to claim 9, in which the first speaker further includes a first electromagnetic drive device for generating a first drive that vibrates the first mechanical structure to generate a first sound wave; A the second speaker further includes a second electromagnetic drive device for generating a second drive that vibrates the second mechanical structure to generate a second sound wave. 12. The audio output device according to claim 11, in which the first electromagnetic excitation device includes a first coil; A the second electromagnetic excitation device includes a second coil, wherein the winding diameter of the first coil is greater than the winding diameter of the second coil, or the electrical resistivity of the first coil is less than the electrical resistivity of the second coil, or at the same input current, the first excitation generated by the first electromagnetic excitation device is greater than the second excitation generated by the second electromagnetic excitation device. 13. The audio output device according to claim 11, in which the first speaker includes a first resistance; A the second speaker includes a second resistance, wherein the first resistance is less than the second resistance. 14. The audio output device of claim 11, further comprising a power amplification circuit connected to the first speaker and a signal processing circuit, wherein the power amplification circuit is configured to amplify the first electrical signal, and the first speaker is configured to receive the amplified first electrical signal. 15. The audio output device of claim 11, further comprising a power attenuation circuit connected to the second speaker and a signal processing circuit, wherein the power attenuation circuit is configured to attenuate the second electrical signal, and the second speaker is configured to receive the attenuated second electrical signal.