CN113596647A

CN113596647A - Sound output device and method for regulating sound image

Info

Publication number: CN113596647A
Application number: CN202010366969.6A
Authority: CN
Inventors: 付峻江; 张磊; 廖风云; 齐心
Original assignee: Shenzhen Voxtech Co Ltd
Current assignee: Shenzhen Voxtech Co Ltd
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2021-11-02

Abstract

The application provides a sound output apparatus and a method of adjusting sound image. The method for adjusting sound image includes: acquiring a volume difference between the first sound wave and the second sound wave; and adjusting a time difference between the first sound wave and the second sound wave. The sound output apparatus and the method of adjusting sound images according to the present application can correct the deviation of sound images perceived by a user due to the difference in quality of the first mechanical structure and the second mechanical structure.

Description

Sound output device and method for regulating sound image

Technical Field

The present invention relates to the field of acoustics, and more particularly, to a sound output apparatus and a method of adjusting sound images.

Background

When the bone conduction earphone works, the vibration amplitude of the bone conduction loudspeaker is positively correlated with the volume generated by the bone conduction loudspeaker. The shell quality of the bone conduction loudspeaker has obvious influence on the vibration amplitude of the bone conduction loudspeaker, and further influences the volume generated by the loudspeaker. In the product design of the bone conduction earphone, it is sometimes necessary to arrange additional functional modules, such as a headset microphone (a microphone with an extension rod added), a button, and the like, on the bone conduction speaker on one side. The keys arranged on the bone conduction speaker change the mass distribution on the bone conduction speaker and thus affect the volume produced by the speaker. Meanwhile, since functional modules such as the headset microphone or the keys are only required to be arranged on one side, and the other side is not arranged, the volumes of the speakers on the two sides are not consistent (the volume of the speaker on one ear is larger than that of the speaker on the other ear), and sound image deviation is caused. If the volume difference between the left and right speakers is large, the hearing of the user may be damaged by long-term use. Therefore, the sound image needs to be adjusted to be centered, and/or the volumes of the speakers at the two sides of the earphone need to be adjusted to be consistent.

Disclosure of Invention

The following presents a simplified summary of the application in order to provide a basic understanding of some aspects of the application. It should be understood that this section is not intended to identify key or critical elements of the application, nor is it intended to be limiting as to the scope of the application. Its sole purpose is to present some concepts of the disclosure in a simplified form. More details will be explained in more detail in the rest of the application.

As described above, for the bone conduction earphone, the functional module attached to the bone conduction speaker on one side increases the mass of the bone conduction speaker housing, which causes the volume of the speaker on the side to decrease, and the volumes of the left and right bone conduction earphones are different. When the volume difference between the left and right earphones is large, the sound image of the earphones is obviously deviated, and even hearing loss is caused after long-term use.

For solving the technical problem of volume difference and acoustic image skew that the uneven quality of speaker brought in bone conduction earphone both sides, this application discloses a sound output device includes: a signal processing circuit operable to generate a first electrical signal and a second electrical signal based on target sound information; the first loudspeaker is electrically connected with the signal processing circuit, and is used for receiving a first electric signal from the signal processing circuit during operation and converting the first electric signal into a first sound wave; and a second speaker electrically connected to the signal processing circuit, and operable to receive a second electrical signal from the signal processing circuit and convert the second electrical signal into a second sound wave, wherein the sound output device requires a first time period for converting the target sound information into the first sound wave and a second time period for converting the target sound information into the second sound wave, and the first time period is shorter than the second time period by a time difference.

In some embodiments, 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 at the same magnitude and frequency of the electrical signal input.

In some embodiments, the volume of the first sound wave differs from the volume of the second sound wave by no more than 3dB for the same magnitude and frequency of electrical signal input.

In some embodiments, the first speaker generates the first sound wave by exciting a first mechanical structure; and the second loudspeaker generates a second sound wave by exciting a second mechanical structure, wherein the mass of the first mechanical structure is greater than the mass of the second mechanical structure, resulting in a volume of sound wave output by the first loudspeaker being less than a volume of sound wave output by the second loudspeaker under input of electrical signals of the same amplitude and frequency.

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

In some embodiments, the time difference occurs during the process in which the sound output device converts the target sound information into the first electrical signal and the second electrical signal.

In some embodiments, the time difference occurs during the conversion of the first electrical signal into the first sound wave by the first speaker and the conversion of the second electrical signal into the second sound wave by the second speaker.

In some embodiments, the time difference is no greater than 3 ms.

The application also discloses a method for adjusting sound image. The method of adjusting sound images configured to adjust sound images of first and second speakers of a sound output device includes: acquiring a volume difference between the first sound wave and the second sound wave; and adjusting the time difference.

In some embodiments, the difference in volume of the first sound wave and the second sound wave is no greater than 3 dB.

In some embodiments, said adjusting the time difference of the first sound wave and the second sound wave comprises: adjusting a phase difference of the first sound wave and the second sound wave.

In summary, the present application provides a sound output apparatus and a method for adjusting sound image, which correct the sound image offset perceived by a user due to the quality difference between a first mechanical structure and a second mechanical structure by setting the time difference between a first sound wave and a second sound wave, in view of the technical problems of volume difference and sound image offset caused by the non-uniform quality of speakers at both sides of a bone conduction headset.

Drawings

The following drawings describe in detail exemplary embodiments disclosed in the present application. Wherein like reference numerals represent similar structures throughout the several views of the drawings. Those of ordinary skill in the art will understand that the present embodiments are non-limiting, exemplary embodiments and that the accompanying drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of the present disclosure, as other embodiments may equally fulfill the inventive intent of the present application. It should be understood that the drawings are not to scale. Wherein:

fig. 1 illustrates an external view of a sound output device provided according to some embodiments of the present application;

FIG. 2 illustrates a schematic structural diagram of an audio output device provided in accordance with some embodiments of the present application;

FIG. 3 illustrates a schematic structural diagram of an electromagnetic excitation device provided in accordance with some embodiments of the present application;

fig. 4 illustrates a schematic structural diagram of a bone conduction speaker provided in accordance with some embodiments of the present application;

FIG. 5 illustrates a vibration model schematic of a bone conduction speaker provided in accordance with some embodiments of the present application;

FIG. 6 illustrates vibration test results of a housing in operation provided in accordance with some embodiments of the present application;

fig. 7 illustrates a schematic structural diagram of a moving coil speaker provided in accordance with some embodiments of the present application;

fig. 8 is a flowchart illustrating a method of adjusting volume according to an embodiment of the present application; and

fig. 9 is a flowchart illustrating a method of adjusting sound images according to an embodiment of the present application.

Detailed Description

The following description is presented to enable any person skilled in the art to make and use the present disclosure, and is provided in the context of a particular application and its requirements. These and other features of the present disclosure, as well as the operation and function of the related elements of the structure, and the combination of parts and economies of manufacture, may be particularly improved upon in view of the following description. All of which form a part of the present disclosure, with reference to the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the disclosure. Various local modifications to the disclosed embodiments will be readily 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 disclosure. Thus, the present disclosure is not to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the claims.

In this application, bone conduction sound wave refers to sound wave in which mechanical vibration is conducted into the ear through the bone (also referred to as bone conduction sound), and air conduction sound wave refers to sound wave in which mechanical vibration is conducted into the ear through the air (also referred to as air conduction sound).

The application provides a volume adjusting method. The volume adjusting method may be used to adjust the volume of sound waves output by the sound output device. The sound waves may include bone-conducted sound waves and/or air-conducted sound waves. The sound output device may include, but is not limited to, an earphone, a hearing aid, a helmet, and the like. The headset may include, but is not limited to, a wired headset, a wireless headset, a bluetooth headset, and the like. The earphones may include, but are not limited to, bone conduction speakers, air conduction speakers.

Fig. 1 shows an external view of an audio output device 300 according to an embodiment of the application. Fig. 2 shows a schematic structural diagram of an audio output device 300 according to an embodiment of the present application. Referring to fig. 2, the sound output apparatus 300 may include a first speaker 310, a second speaker 320, and a signal processing circuit 330.

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

The target sound information 10 may include a video having a specific data format, an audio file, or data or a file that can be converted into sound through a specific way. The target audio information 10 may be from a storage component of the audio output device 300 itself, or may be from an information generation, storage, or transmission system other than the audio output device 300. The target sound information 10 may include one or a combination of more of an electrical signal, an optical signal, a magnetic signal, a mechanical signal, and the like. The target sound information 10 may be from one signal source or a plurality of signal sources. The multiple signal sources may or may not be correlated. In some embodiments, the signal processing circuit 330 may acquire the target sound information 10 in a variety of different ways. The acquisition of the target sound information 10 may be wired or wireless, and may be real-time or delayed. For example, the audio output device 300 may receive the target audio information 10 in a wired or wireless manner, or may directly obtain data from a storage medium to generate the target audio signal 10. For another example, the sound output device 300 may include a component having a sound collection function, and the sound collection function is configured to obtain an electrical signal meeting a specific requirement by picking up sound in the environment and converting mechanical vibration of the sound into an electrical signal and amplifying the electrical signal by a processor. In some embodiments, the wired connection may include a metal cable, an optical cable, or a hybrid cable of metal and optical, such as a coaxial cable, a communication cable, a flexible cable, a spiral cable, a non-metal sheath cable, a multi-core cable, a twisted pair cable, a ribbon cable, a shielded cable, a cell cable, a twinax cable, a parallel twin-core wire, a twisted pair cable, or a combination of one or more thereof. The above-described examples are merely used for convenience of illustration, and the medium for wired connection may be other types of transmission medium, such as other transmission medium of electrical or optical signals. The wireless connection may include radio communication, free space optical communication, acoustic communication, electromagnetic induction, and the like. Wherein the radio communications may include the IEEE802.11 family of standards, the IEEE802.15 family of standards (e.g., Bluetooth and cellular technologies, etc.), first generation mobile communication technologies, second generation mobile communication technologies (e.g., FDMA, TDMA, SDMA, CDMA, and SSMA, etc.), general packet radio service technologies, third generation mobile communication technologies (e.g., CDMA2000, WCDMA, TD-SCDMA, and WiMAX, etc.), fourth generation mobile communication technologies (e.g., TD-day E and FDD-LTE, etc.), satellite communications (e.g., GPS technologies, etc.), Near Field Communications (NFC), and other technologies operating in the ISM band (e.g., 2.4GHz, etc.); free space optical communication may include visible light, infrared signals, and the like; the acoustic communication may include acoustic waves, ultrasonic signals, etc.; electromagnetic induction may include near field communication techniques and the like. The above examples are for convenience of illustration only, and the medium for the wireless connection may be of other types, such as Z-wave technology, other premium civilian radio bands, and military radio bands, among others. For example, as some application scenarios of the present application, the sound output apparatus 300 may acquire the target sound information 10 from other devices through bluetooth technology.

In some embodiments, in order to make the first sound wave 21 and the second sound wave 22 have specific output characteristics (e.g., frequency, phase, amplitude, etc.), the signal processing circuit 330 may process the target sound information 10 such that the first electrical signal 11 and the second electrical signal 12 output by the signal processing circuit 330 respectively contain specific frequency components.

Several filter/filter banks 331 may be provided in the signal processing circuit 330 in some embodiments. The several filter/filter banks 331 may process the received electrical signals and output electrical signals containing different frequencies. The filter/filter bank 331 includes, but is not limited to, analog filters, digital filters, passive filters, active filters, and the like. In some embodiments, a dynamic range controller 332 may be disposed in the signal processing circuit 330. The dynamic range controller 332 may be configured to compress and amplify the input signal to make the sound softer or louder. In some embodiments, an active leakage reduction circuit 333 may be disposed in the signal processing circuit 330 to reduce the leakage of the sound output device 300. In some embodiments, a feedback circuit 334 may be disposed in the signal processing circuit 330. The feedback circuit 334 may feed back sound field information to the signal processing circuit 330. In some embodiments, a power conditioning circuit 335 may be disposed in the signal processing circuit 330 to condition the amplitude of the received electrical signal. The power conditioning circuit 335 may include a power amplification circuit to amplify the signal to the first electrical signal 11 and/or the second electrical signal 12. The power conditioning circuit 335 may also include a power attenuation circuit to attenuate the signal amplitude of the first electrical signal 11 and/or the second electrical signal 12. In some embodiments, an equalizer 338 may be disposed in the signal processing circuit 330. The equalizer 338 may be configured to individually gain or attenuate the received signal according to a particular frequency band. In some embodiments, a divider circuit 339 may be included in the signal processing circuit 330. The frequency dividing circuit may decompose the received electrical signal into a high frequency signal component and a low frequency signal component.

The first speaker 310 is electrically connected 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 the first sound wave 21. The first speaker 310 may be a transducing device. In some embodiments, the first speaker 310 may convert the received first electrical signal 11 into mechanical vibrations. Further, the first acoustic wave 21 is generated by the mechanical vibration. For example, the first loudspeaker 310 may comprise a first mechanical structure 311 and a first excitation means 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 combination of a bone conduction speaker and an air conduction speaker.

The first excitation device 312 may be an input of the energy charging device. The first excitation device 312 receives the first electrical signal 11 from the signal processing circuit 330 and converts the first electrical signal 11 into a first excitation. The first excitation excites the first mechanical structure 311 to vibrate. That is, the first loudspeaker 310 converts the electrical energy of the received first electrical signal 11 into mechanical energy for vibrating the first mechanical structure 311 via the first excitation means 312 and the first mechanical structure 311.

The first excitation means 412 generates said first excitation to excite the first mechanical structure 411 to vibrate. In some embodiments, the first excitation device 412 may be an electromagnetic excitation device. The first excitation may be a magnetic force, an electromagnetic force and/or an ampere force generated by the electromagnetic excitation means. Of course, the first excitation device 412 may also be other types of excitation devices, and the application is not particularly limited. The excitation device receives the first electrical signal 11 from the signal processing circuit 430 and generates a first excitation. The manner in which the excitation device generates the first excitation may include, but is not limited to, moving coil, electrostatic, piezoelectric, moving iron, pneumatic, electromagnetic, and the like.

By way of example, fig. 3 illustrates a schematic structural diagram of a first excitation device 412 provided in accordance with an embodiment of the present application. The first excitation means 412 shown in fig. 3 may be an electromagnetic excitation means. In particular, the first excitation means 412 may comprise a magnetic element 610 and a coil 620.

The magnetic member 610 may generate a magnetic field. For example, the magnetic member 610 may have magnetism. In some embodiments, the magnetic properties may be constant. The magnetic member 610 may include or be made of a permanent magnet. The permanent magnet may be a natural magnet or an artificial magnet. By way of example, the permanent magnets may include, but are not limited to, neodymium iron boron magnets, samarium cobalt magnets, alnico magnets, and the like. The permanent magnet should have as high a coercivity, remanence and maximum magnetic energy product as possible to ensure that the permanent magnet has stable magnetic properties and is capable of storing maximum magnetic energy.

The coils 620 may be wound in groups in a certain direction. The coil 620 may be disposed within the magnetic field generated by the magnetic member 610. The coil 620 may include a first end 621 and a second end 622. The electrical signal may enter the coil 620 from the first end 621, flow through the coil 620, and exit the coil 620 from the second end 622 in the form of an electrical current.

From electromagnetic knowledge, the energized coil 620 experiences an ampere force in the magnetic field. And, the magnitude of the ampere force may be determined by F ═ B · I · L. Where F represents the magnitude of the ampere force to which coil 620 is subjected; the direction of F may be determined according to ampere's rule. F drive coil 620 to vibrate. The coil 620 may be coupled to a mechanical structure 630, and further, the coil 620 drives the mechanical structure 630 to vibrate. As an example, the mechanical structure 630 may be a first mechanical structure 311 generating a first acoustic wave 21. That is, F may excite the first mechanical structure 311 as an external excitation signal to generate vibration.

B is the magnetic field strength of the magnetic field generated by the magnetic member 610. The magnitude of the magnetic field strength of the magnetic field generated by the magnetic element 610 is related to the material of the magnetic element 610. In some embodiments, the strength B of the magnetic field generated by the magnetic element 610 has a positive correlation with the coercivity, remanence, and maximum energy product of the magnetic element 610.

I is the magnitude of the current passing in coil 620. I is related to the electrical signal received by the first excitation means 412. Typically, the electrical signal will be input to the coil 620 in the form of a pulsed voltage. The magnitude of the pulse voltage between the first end 621 and the second end 622 of the coil 620 (i.e. the electrical signal input to the electromagnetic excitation means 600) is denoted by Ut. The current I flowing through the coil 620 may be expressed as I ═ U_tand/R. Where R represents the magnitude of the resistance between the first end 621 and the second end 622. According to the physics, the resistance between the first end 621 and the second end 622 can be determined according to the physical knowledge

And (4) calculating. Where ρ represents the resistivity of the windings of coil 620; l represents the length of coil 620; s denotes the diameter of the winding of the coil 620.

In summary, the magnitude of the excitation F (i.e. the ampere force to which the coil is subjected) generated in the first excitation means 412 can be found to be:

with continued reference to fig. 2, the first mechanical structure 311 may be an output of the energy conversion device. The first mechanical structure 311 vibrates to generate a first acoustic wave 21. The first mechanical structure 311 may generate mechanical vibrations under the action of a first excitation; further, the first acoustic wave 21 is generated based on the mechanical vibration. In some embodiments, the first mechanical structure 311 may be a component that emits sound directly by vibration after being excited. For example, when the first speaker is a bone conduction speaker, the first mechanical structure 311 may be a housing of the bone conduction speaker. And when the first speaker is a moving coil air conduction speaker, the first mechanical structure 311 may comprise a wool or paper cone of said moving coil air conduction speaker.

Since the first acoustic wave 21 is generated by the vibration of the first mechanical structure 311, in order to analyze the characteristics of the first acoustic wave 21, it is necessary to analyze the vibration process of the first mechanical structure 311. Next, the present application takes the first speaker 310 as a bone conduction speaker as an example to analyze the vibration process of the first mechanical structure 311.

Fig. 4 shows a schematic structural diagram of a bone conduction speaker 100 provided in accordance with some embodiments of the present application. Bone conduction speaker 100 may include a housing 120 and a magnetic circuit 130.

The magnetic circuit 130 may act as an excitation means to generate an excitation f. The magnetic circuit 130 and the case 120 are connected by a vibration transmission plate 140.

The housing 120 may be attached to the ear hook 110. The point P at the top of the ear hook 110 is well attached to the head. Thus, the top point P may be considered a fixed point. When the bone conduction speaker 100 operates, the housing 120 may vibrate by the excitation f and generate sound waves. Based on the force interaction, the magnetic circuit 130 is also subjected to a force (i.e., "f" in the figure) with the same magnitude and opposite direction as f during the vibration of the housing 120. To facilitate the analysis of the relationship between the sound waves generated by the bone conduction speaker 100 and the housing 120 and the magnetic circuit 130, the housing 120 and the magnetic circuit 130 can be simplified to a two-degree-of-freedom vibration system.

Fig. 5 shows a model of a two-degree-of-freedom vibration system provided according to an embodiment of the present application. In the model shown in fig. 5: mass block m₁May represent the housing 120; mass block m₂May represent a magnetic circuit 130; elastic connecting piece k₁May represent the vibration plate 140; elastic connecting piece k₂May represent an ear hook 110. Elastic connecting piece k₁And k₂Respectively is c₁And c₂. The housing 120 and the magnetic circuit 130 are subjected to a force f and a force-f, respectively, to generate vibrations. f is the magnitude of the system excitation; the direction of f is as shown in fig. 5. The composite vibration system composed of the housing 120, the magnetic circuit 130, the vibration transmission plate 140 and the ear hook 110 is fixed at the point P on the top end of the ear hook 110.

The kinetic analysis is performed on the casing 120 and the magnetic circuit 130, respectively, to obtain the kinetic 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 be expressed in the frequency domain as a series of simple harmonic vibration sums, thus assuming that

Wherein F₀Is the excitation amplitude; the steady state response of the system can be expressed as

Wherein

Is the response amplitude.

Substituting F and X into equation (2) yields equation (3).

Introducing a mechanical impedance matrix Z (ω):

substituting the mechanical impedance matrix Z (omega) into the formula (3), solving to obtain the response amplitude of the vibration system as follows:

wherein the content of the first and second substances,

from this, it can be obtained that the response amplitude of the vibration system is:

the housing 120 vibrates to generate sound waves. Thus, the shell 120 (i.e., the mass m)₁) And (6) carrying out analysis. Substituting the mechanical impedance matrix Z (ω) into equation (4) yields the magnitude of the response of the housing 120 as:

as can be seen from equation (6), the amplitude X of the vibration of the housing 120 under forced vibration₁Simultaneously influenced by the following parameters: frequency of excitation F (magnitude equal to 1/ω), amplitude of excitation F₀Mass m of the housing 120₁Mass m of magnetic circuit 130₂Stiffness k of vibration transmission plate 140₁And damping c₁And the stiffness k of the earhook 110₂And damping c₂. For example, the amplitude F of the excitation F is such that the other parameters remain unchanged₀Amplitude of vibration X with the housing 120₁In a proportional relationship. Amplitude F of excitation F₀The larger the amplitude X of the housing 120₁The larger. As another example, the mass m of the housing 120 of the bone conduction speaker 100 may be maintained constant while maintaining other parameters₁The larger the amplitude X of the housing 120₁The smaller; mass m of magnetic circuit 130₂The larger the amplitude X of the housing 120₁The larger. Thus, when the above parameters are changed, the amplitude X of the housing 120 is changed₁And consequently also changes. Amplitude X of the housing 120 without taking into account differences in transmission media and transmission distances₁Which is positively correlated with the volume of the sound wave generated by the vibration of the housing 120. Amplitude X₁The larger the sound wave, the greater the volume of the sound wave; amplitude X₁The smaller the sound volume of the sound wave.

Fig. 6 illustrates vibration test results of the housing 120 when the bone conduction speaker 100 provided according to some embodiments of the present application is in operation. In vibration testing, physical quantities used to evaluate the magnitude of vibration or volume may include, but are not limited to, the velocity of the vibration source, displacement, sound pressure level, and the like. As an example, the acceleration level (unit: dB) of the vibration source is taken as the physical quantity evaluating the vibration in the vibration test shown in fig. 6. In fig. 6, the solid line represents the mass m of the case 120₁A curve of the vibration acceleration level of the bone conduction speaker 100 as a function of the frequency of the excitation f in the case of (1); the dashed line represents the mass m of the housing 120₁The vibration acceleration level of bone conduction speaker 100 after an increase of 50% is plotted as a function of the frequency of excitation f.

As can be seen in fig. 6, the acceleration level of the housing 120 vibration is frequency and mass related. Relative initial shell mass m₁When the housing 120 has a mass m₁Becomes 1.5m₁The acceleration level of the shell vibration is not obviously reduced only in the low frequency band below 160Hz, and is reduced by about 3-4dB in both the middle frequency band and the high frequency band. That is, when the mass of the housing 120 is increased by 0.5 times at the middle and high frequency bands, the amplitude of the vibration of the housing 120 is decreased by 3-4 dB.

The above conclusions are based on the results obtained from speaker modeling. Within the hearing range of the human ear, low frequencies may refer to a frequency band of substantially 20Hz to 150Hz, medium frequencies may refer to a frequency band of substantially 150Hz to 5KHz, high frequencies may refer to a frequency band of substantially 5KHz to 20KHz, medium and low frequencies may refer to a frequency band of substantially 150Hz to 500Hz, and medium and high frequencies may refer to a frequency band of 500Hz to 5 KHz. It will be appreciated by those skilled in the art that the above frequency band division is only given roughly as an example. The definition of the frequency bands can be changed with different industries, different application scenes and different classification standards. For example, in some other application scenarios, the low frequency refers to a frequency band of substantially 20Hz to 80Hz, the medium-low frequency may refer to a frequency band between substantially 80Hz and 160Hz, the medium frequency may refer to a frequency band of substantially 160Hz to 1280Hz, the medium-high frequency may refer to a frequency band of substantially 1280Hz to 2560Hz, and the high frequency band may refer to a frequency band of substantially 2560Hz to 20 KHz.

It should be noted that although the foregoing description only describes the relationship between the volume generated by the bone conduction speaker and the mass of the housing, the first speaker 310 described in the present application is not limited to the bone conduction speaker. For example, in the case of an air conduction speaker, the first speaker 310 still performs well in the above analysis.

As an example, fig. 7 shows a schematic structural diagram of a moving-coil speaker 500 provided according to an embodiment of the present application. The moving coil loudspeaker shown in figure 7 may be an air conduction loudspeaker. Specifically, the moving-coil speaker 500 may include a magnetic circuit component 520, a vibration component 530, and a support auxiliary component 510.

The support auxiliary assembly 510 may provide support for the vibration assembly 530 and the magnetic circuit assembly 520. The support auxiliary member 510 may include an elastic member 511. The vibration member 530 may be fixed on the support auxiliary member 510 by the elastic member 511.

The magnetic circuit assembly 520 may convert the electrical signal to an excitation F. The excitation F may act on the vibration assembly 530.

The vibration assembly 530 may vibrate and generate sound waves under the excitation F.

By kinetic analysis, it can be concluded that: similar to the bone conduction speaker 100, the amplitude of vibration of the vibration member 530 in the moving-coil speaker 500 under the excitation F is related to the equivalent mass m, the excitation F, the damping c, and the stiffness k of the vibration member 530. Wherein, the larger the equivalent mass of the vibration component 530, the smaller the amplitude of the vibration, with other parameters being unchanged. With other parameters being constant, the larger the excitation F, the larger the amplitude of the vibration. For brevity, the process of kinetic analysis is not described in detail.

In summary, the volume of the first acoustic wave 21 generated by the vibration of the first mechanical structure 311 is related to the frequency of the first electrical signal 11 and the mass of the first mechanical structure 311. Wherein the larger the mass of the first mechanical structure 311, the smaller the volume of the first sound wave 21.

With continued reference to fig. 2, the second speaker 320 is electrically connected to the signal processing circuit 330. The second speaker 320 may receive the second electrical signal 12 from the signal processing circuit 330 and convert the second electrical signal 12 into the second sound waves 22. The second speaker 320 may be a transducing device. In some embodiments, the second speaker 320 may convert the received electrical signals into mechanical vibrations. Further, the second acoustic wave 22 is generated by the mechanical vibration. In some embodiments, the second speaker 320 may include a second mechanical structure 321 and a second excitation device 322. The second mechanical structure 321 may be identical or similar in structure and function to the first mechanical structure 311; the second activation device 322 may be identical or similar in structure and function to the first activation device 312. For brevity, the structure and function of the second mechanical structure 321 and the second actuation device 322 will not be described in detail.

As with the first speaker 310, the volume of the second sound wave 22 generated by the second mechanical structure 321 in the second speaker 320 vibrating is related to the frequency of the second electrical signal 21 and the mass of the second mechanical structure 321. Wherein the larger the mass of the second mechanical structure 321, the smaller the sound volume of the second acoustic wave 22.

With continued reference to fig. 1, in some embodiments, an additional device 940 is disposed on one end of the first speaker 310. By way of example, the add-on device 940 may include function keys disposed on a side housing of the bone conduction headset. By way of example, the additional device 940 may comprise a headset microphone arranged on a side housing of the bone conduction headset. The headset microphone may include, but is not limited to, components such as a base, a microphone link, and a microphone. The arrangement of the headset microphone can improve the conversation quality of the bone conduction headset. The quality of the additional device 940 may not be negligible compared to the quality of the sound output apparatus 300. Since the additional device 940 is arranged on a single side of the sound output apparatus 300 (i.e. on the side of the first loudspeaker 310), this may result in a mass of the first mechanical structure 311 in the first loudspeaker 310 being larger than a mass of the second mechanical structure 311 in the second loudspeaker 310. For example, the mass of the housing of the bone conduction speaker provided with the headset microphone on one side is greater than the mass of the housing of the bone conduction speaker not provided with the headset microphone on the other side.

As can be seen from the foregoing description, if the mass of the first mechanical structure 311 is larger than the mass of the second mechanical structure 321 under the same electrical signal input without considering the differences of damping and stiffness, etc., the amplitude of the vibration of the first mechanical structure 311 is smaller than the amplitude of the vibration of the second mechanical structure 321. Regardless of the difference between the transmission medium and the transmission distance, the volume of the first sound wave emitted from the first speaker 310 heard by the user is smaller than the volume of the second sound wave emitted from the second speaker 320.

If a difference (hereinafter, referred to as a volume difference) between the volume of the first sound wave and the volume of the second sound wave heard by the user exists for a long time, the user's hearing may be impaired. (e.g., sounds heard by both ears of the user may be damaged by a volume difference greater than 3dB for a long period of time.) furthermore, the presence of a volume difference between the first sound wave and the second sound wave heard by the user may cause a shift between the sound image perceived by the user and the actual sound image. Therefore, the volumes of the first sound wave and the second sound wave need to be adjusted so that the volumes of the first sound wave and the second sound wave are as consistent as possible to avoid hearing impairment and sound image deviation caused by the volume difference.

Fig. 8 shows a flowchart of a method S200 for adjusting volume according to an embodiment of the present application. The process S200 may be used to adjust the volume of the sound output by the first speaker 310 and the second speaker 320 of the sound output device 300. The process S200 may also be used to adjust the sound image perceived by the user of the sound output device 300. Specifically, the process S200 may include: s210, acquiring a volume difference between the first sound wave and the second sound wave; and S220, adjusting the amplitude difference of the first excitation and the second excitation.

S210, acquiring the volume difference of the first sound wave and the second sound wave. In some embodiments, the volume difference is greater than 3 dB.

S220, adjusting the amplitude difference of the first excitation and the second excitation. From the foregoing description, it can be seen that the mass of the first mechanical structure is greater than the mass of the second mechanical structure, resulting in the amplitude of the vibration of the first mechanical structure being less than the amplitude of the vibration of the second mechanical structure, further resulting in the volume of the first sound wave being less than the volume of the second sound wave. Thus, the amplitude of the first mechanical structure may be adjusted by adjusting the amplitude of the first excitation; the amplitude of the second mechanical structure may be adjusted by adjusting the amplitude of the second excitation; thereby correcting the difference in sound volume caused by the difference in mass between the first mechanical structure and the second mechanical structure.

For ease of understanding, in the following description of the present application, reference is made to F₁Representing the magnitude of the first excitation by F₂Indicating the magnitude of the second excitation by M₁Representing the mass of the first mechanical structure, in M₂Mass of the second mechanical structure, denoted by S₁The cross-sectional area of the first coil winding is represented by S₂The cross-sectional area of the winding of the second coil is expressed by rho₁Representing the resistivity of the first coil winding in p₂The resistivity of the second coil winding is shown as B₁Indicates the magnetic field strength of the first magnetic member by B₂Indicates the magnetic field strength of the second magnetic member by R₁The resistance of the first coil winding (hereinafter referred to as the first resistance) is represented by R₂The resistance of the second coil wire (hereinafter referred to as the second resistance) is shown.

Referring to equations (1) and (6), the first excitation F can be adjusted₁And/or a second excitation F₂So as to make the first mechanical structure 311 vibrate with an amplitude X₁As well as the secondAmplitude X of vibration of mechanical structure 321₂The volume of the first sound wave 21 is made to coincide with the volume of the second sound wave 22.

In some embodiments, the first excitation F of different magnitudes may be obtained by adjusting the diameter of the first coil wire and/or the diameter of the second coil wire₁And a second excitation F₂Further, the volume of the first sound wave 21 is made to coincide with the volume of the second sound wave 22. Due to M₁＞M₂S may be increased by increasing the diameter of the first coil wire and/or decreasing the diameter of the second coil wire₁＞S₂. The first excitation F generated by the first excitation means 312 is according to equation (1)₁Greater than the second excitation F generated by the second excitation means 422₂. In combination with equation (6), the first excitation F₁Greater than the second excitation F₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave 21 is the same as the power of the second sound wave 22, and the volume of the first sound wave 21 heard by the user is the same as the volume of the second sound wave 22. This corrects for the mass difference (M) between the first 311 and second 321 mechanical structures₁＞M₂) Resulting in a volume difference. Further, the sound image shift due to the volume difference is also avoided.

Further, the method of adjusting the volume by adjusting the diameter of the coil keeps the overall size of the coil constant while the output volume is made uniform. Thus, the structure and size of each component in the sound output device can be maintained unchanged.

As an example, when the maximum volume required for the earphone is relatively large, the bone conduction speaker on the side with the additional device uses a coil with a wire diameter thicker than that of the speaker on the side without the additional device. For example, the ratio of the wire diameter of the thick wire used for the speaker coil on the side with the additional device to the wire used for the speaker coil on the side without the additional device is not less than any of the following values or a range between any two values: 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09 and 2.0.

As an example, when the headset requires relatively small power consumption, the bone conduction speaker on the side without the additional device uses a coil having a wire diameter thinner than that of the speaker wire on the side with the additional device. As an example, the ratio of the wire diameter of the thin wire used by the no-attachment-device-side speaker coil to the wire used by the no-attachment-device-side speaker coil is not more than any of the following values or a range between any two values: 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99.

Furthermore, the resistivity of the first coil and/or the resistivity of the second coil can be adjusted to obtain different magnitudes of the first excitation F₁And a second excitation F₂Further, the volume of the first sound wave 21 is made to coincide with the volume of the second sound wave 22. Due to M₁＞M₂The resistivity p of the first coil may be reduced₁And/or increasing the resistivity p of the second coil₂Let ρ be₁＜ρ₂. As an example, a particular winding material may be selected such that ρ is₁＜ρ₂. The first excitation F generated by the first excitation means 312 is, according to equation (1), constant with other independent variables₁Greater than the second excitation F generated by the second excitation means 422₂. In combination with equation (6), the first excitation F₁Greater than the second excitation F₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave 21 is the same as the power of the second sound wave 22, and the volume of the first sound wave 21 heard by the user is the same as the volume of the second sound wave 22. This corrects for the mass difference (M) between the first 311 and second 321 mechanical structures₁＞M₂) Resulting in a volume difference. Further, the sound image shift due to the sound volume difference is also corrected.

Furthermore, the magnetic field intensity B of the first magnetic member can be adjusted₁And/or the magnetic field strength B of the second magnetic member₂To obtain first excitations F of different magnitudes₁And a second excitation F₂Further, the volume of the first sound wave 21 is made to coincide with the volume of the second sound wave 22. Due to M₁＞M₂The magnetic field intensity B of the first magnetic member can be increased₁And/or reducing the magnetic field strength B of the second magnetic member₂Let B be₁＞B₂. The situation where other independent variables are not changedIn this case, the first excitation F generated by the first excitation device 312 is according to the formula (1)₁Greater than the second excitation F generated by the second excitation means 422₂. In combination with equation (6), the first excitation F₁Greater than the second excitation F₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave 21 is the same as the power of the second sound wave 22, and the volume of the first sound wave 21 heard by the user is the same as the volume of the second sound wave 22. This corrects for the mass difference (M) between the first 311 and second 321 mechanical structures₁＞M₂) Resulting in a volume difference. Further, the sound image shift due to the sound volume difference is also corrected.

It is also possible to increase the size of the first magnetic member and/or decrease the size of the second magnetic member such that B₁＞B₂。

For example, magnetic members made of materials having different magnetic properties may be selected for use as B₁＞B₂. For example, the first magnetic member is made of a material with stronger magnetism; the second magnetic part is made of a material with weaker magnetism. In some embodiments, the remanence of the first magnetic member is greater than the remanence of the second magnetic member such that the first electromagnetic excitation device generates a magnetic field strength B₁Is greater than the magnetic field intensity B generated by the second electromagnetic excitation device₂. In some embodiments, the coercivity of the first magnetic member is greater than the coercivity of the second magnetic member such that the magnetic field strength B generated by the first electromagnetic excitation device is greater₁Is greater than the magnetic field intensity B generated by the second electromagnetic excitation device₂. In some embodiments, the magnetic energy product of the first magnetic member is greater than the magnetic energy product of the second magnetic member, so that the magnetic field intensity B generated by the first electromagnetic excitation device is larger than the magnetic energy product of the second magnetic member₁Is greater than the magnetic field intensity B generated by the second electromagnetic excitation device₂。

In some embodiments, the first resistance R may be adjusted₁And/or a second resistance R₂To obtain first excitations F of different magnitudes₁And a second excitation F₂Further, the volume of the first sound wave 21 is made to coincide with the volume of the second sound wave 22. In the present application, the first electrodeResistance R₁Refers to the overall resistance of the first loudspeaker, including the internal resistance and possible additional resistance of the first loudspeaker; a second resistor R₂Refers to the overall resistance of the second loudspeaker, including the internal resistance and possible additional resistance of the second loudspeaker. Due to M₁＞M₂By reducing the first resistance R₁And/or increasing the second resistance R₂Let R be₁＜R₂. The first excitation F generated by the first excitation means 312 is, according to equation (1), constant with other independent variables₁Greater than the second excitation F generated by the second excitation means 422₂. In combination with equation (6), the first excitation F₁Greater than the second excitation F₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave 21 is the same as the power of the second sound wave 22, and the volume of the first sound wave 21 heard by the user is the same as the volume of the second sound wave 22. This corrects for the mass difference (M) between the first 311 and second 321 mechanical structures₁＞M₂) Resulting in a volume difference. As an example, when the headset has no particularly stringent requirements for maximum volume and power consumption, the bone conduction speaker on the side without the additional device (such as a headset microphone) is connected in series with a resistor. As an example, the resistance of the resistor in series with the bone conduction speaker on the side without the additional device is not less than 1 Ω. It should be noted that the series resistor is not necessarily a single resistor device, and the same effect can be achieved by the resistance of the wire (e.g., a rear-hanging wire) used in the control circuit.

In addition, the first resistor R can be connected with the second coil in series to form a resistor₁Is less than the second resistance R₂(i.e., R)₁＜R₂) And further corrects the difference in volume due to the difference in mass between the first mechanical structure 311 and the second mechanical structure 321. Furthermore, by adopting the method of connecting the external resistor in series, materials do not need to be added in the production and design processes, and the influence on the production and design is small.

Furthermore, it is also possible to reduce the resistance R of the first coil directly₁And/or increasing the resistance R of the second coil₂So that the first resistor R₁Is less than the second resistance R₂(i.e., R)₁＜R₂) And further corrects the difference in volume due to the difference in mass between the first mechanical structure 311 and the second mechanical structure 321. According to the formula R ═ pl/S, in some embodiments, the resistance of the first coil can be made smaller than the resistance of the second coil by decreasing the resistivity of the first coil and/or increasing the resistivity of the second coil. In some embodiments, the resistance of the first coil may be made smaller than the resistance of the second coil by increasing the length of the wire of the first coil and/or decreasing the length of the wire of the second coil. In some embodiments, the resistance of the first coil may be made smaller than the resistance of the second coil by reducing the diameter of the wire of the first coil and/or increasing the diameter of the wire of the second coil. It should be noted that the mass of the first coil and/or the second coil may also change when the resistivity, the winding length and/or the winding diameter of the first coil and/or the second coil are increased and/or decreased. The mass of the first and second coils will also have an influence on the vibrations of the first and second mechanical structure. Therefore, when adjusting parameters such as resistivity, winding length and/or winding diameter, the influence of other parameters needs to be considered, so that the amplitude of the vibration of the final first mechanical structure 311 is consistent with the amplitude of the vibration of the second mechanical structure 321.

Referring to equation (6), in some embodiments, the amplitudes of the first electrical signal 11 and/or the second electrical signal 12 may also be adjusted to obtain the first excitations F with different amplitudes₁And a second excitation F₂Further, the volume of the first sound wave 21 is made to coincide with the volume of the second sound wave 22.

As an example, since M₁＞M₂We can provide a power amplification circuit in the signal processing circuit 330. For example, the power conditioning circuit 335 may be the 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 first electrical signal 11 and the second electrical signal 12 have the same amplitude without passing through the power conditioning circuit 335, the amplitude of the first electrical signal 11 is greater than the amplitude of the second electrical signal 12 after passing through the power conditioning circuit 335. First of allThe loudspeaker 310 receives the amplified first electrical signal such that the first excitation F generated by the first loudspeaker 310₁Will be larger than the second excitation F generated by the second loudspeaker 320₂Size of (i.e. F)₁＞F₂)。

As an example, since M₁＞M₂We can provide a power attenuation circuit in the signal processing circuit 330. For example, the power conditioning circuit 335 may be the power attenuation circuit. The power attenuation circuit may attenuate 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 attenuated second electrical signal 12. Thus, if the first electrical signal 11 and the second electrical signal 12 have the same amplitude without passing through the power conditioning circuit 335, the second excitation F generated by the second loudspeaker 320 based on the attenuated second electrical signal 12 after passing through the power conditioning circuit 335₂Will be smaller than the first excitation F₁(i.e. F)₁＞F₂). In the case of other independent variables being unchanged, in combination with equation (6), the first excitation F₁Greater than the second excitation F₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave 21 is the same as the power of the second sound wave 22, and the volume of the first sound wave 21 heard by the user is the same as the volume of the second sound wave 22. This corrects for the mass difference (M) between the first 311 and second 321 mechanical structures₁＞M₂) Resulting in a volume difference. As an example, the gain of the audio signal of the bone conduction speaker on both sides of the bone conduction earphone can be adjusted through chip control software in the bone conduction earphone, so that the volumes on both sides of the bone conduction earphone are the same.

Furthermore, in some embodiments, the difference in the sound volume of the first sound wave 21 and the second sound wave 22 caused by the difference in the mass may also be corrected by directly adjusting the mass of the first mechanical structure 311 and/or the second mechanical structure 321 so that the mass of the first mechanical structure 311 is consistent with the mass of the second mechanical structure 321. For example, a headset microphone, function keys, etc. are arranged on one side of the first loudspeaker 310, resulting in a larger mass of the first mechanical structure 311 than the second mechanical structure 321, and we can increase the mass of the second mechanical structure 321 to be the same as the mass of the first mechanical structure 311 by adding additional weight on one side of the second loudspeaker 320. Thus, the first mechanical structure 311 and the second mechanical structure 321 have the same mass, and finally, the volume of the first sound wave 21 is the same as the volume of the second sound wave 22.

It should be noted that, the volume and the power mentioned in the above-mentioned solutions and/or embodiments for adjusting the volume are all in terms of the volume and the power of the sound emitted by the speaker on the headset, not the power consumption of the headset. The above described schemes and/or embodiments for adjusting the volume are not isolated. The above-described schemes and/or embodiments of adjusting the volume may be used alone to adjust the volume across the sound output device 300. The above-described schemes and/or embodiments for adjusting the volume may also be used in combination to adjust the volume at both ends of the sound output device 300. For example, mass adjustment and excitation adjustment may be performed simultaneously. For example, when M₁＞M₂In this case, the combination of the schemes "increase the mass of the second mechanical structure 311", "increase the first excitation", "increase the diameter of the first coil", etc. can be used simultaneously to make the sound volumes of the first speaker 310 and the second speaker 320 consistent.

The above-described solutions and/or embodiments produce good technical results in practical production. As an example, the results of testing three earphone samples are listed below. Sample 1: the bone conduction loudspeaker at one side with low volume uses a coil with thicker wire diameter, and the other side uses a normal coil; sample 2: the bone conduction loudspeaker on one side with large volume uses a coil with a thinner wire diameter, and the other side uses a normal coil; sample 3: the bone conduction loudspeaker on the side with large volume is connected in series with a resistor with certain resistance. The three samples are all added with the same functional module on the bone conduction loudspeaker on one side, and the other side is not provided with the functional module. And playing a white noise signal by using a mobile phone, connecting the earphone samples to be tested through the Bluetooth, and testing the total current of each earphone battery terminal under the same volume. The test results are shown in table 1. During the test, the output voltage of the battery end is basically unchanged (4.0-4.2V).

Table 1 total current on battery side for earphone samples at the same volume

From the test results in table 1, the total current at the battery terminals of the three earphone samples (sample 1, sample 2, and sample 3) with additional functional modules is increased compared to the normal earphone at the same listening volume. Of the three samples, sample 2 (the speaker on the side with large volume uses a coil with a thinner wire diameter, and the speaker on the other side uses a normal coil) has the smallest total current; sample 1 (speaker with small volume side using coil with thicker wire diameter and normal coil on the other side) has the largest total current. Wherein, sample 3 (the bone conduction speaker of the big side of volume connects in series the resistance of certain resistance) only need connect in series a resistance on the circuit board or reach the effect of series resistance through other modes, need not increase the material in production and the design process, and is less to production and design influence.

In addition, different samples were tested for battery life. The test is carried out under the same listening volume (85dB), a white noise signal is played by using a mobile phone, earphone samples needing to be tested are connected through Bluetooth, batteries with the same capacity are used for different earphone samples, the batteries are all in a fully charged state when the test is started, and the actual use time of different samples is shown in a table 2.

TABLE 2 earphone sample Battery usage time

From the test results in table 2, it can be seen that the battery life of the three samples is significantly reduced compared to the normal sample at the same listening volume, the use time of sample 1 is the shortest, and the use time of sample 3 is slightly shorter than that of sample 2, but the difference is not great. The above results are consistent with the previous battery current test results.

As can be seen from the foregoing description, if the volume of the first sound wave 21 heard by the user is smaller than the volume of the second sound wave 22 heard by the user, the difference in the volumes of the two earphones can be compensated by adjusting the earphone design structure. Furthermore, the sound image formed by the headphones can be adjusted for the difference in the volume of the headphones.

The sound image refers to a sound production location point of a sound source in a sound field, that is, the sound image is the orientation of the sound. For the user, the brain of the user determines that the sound emission position of the target sound information (i.e., the sound image perceived by the user) is biased toward the side of the second sound wave 22, which is the side of the second speaker 320, which is louder. And in practice, the distances of the first speaker 310 and the second speaker 320 from the user may be considered to be the same, that is, the actual sound image of the target sound information 10 is centered (i.e., from directly in front of or directly behind the user). That is, a deviation is generated between the sound image perceived by the user and the actual sound image. The application provides a sound image adjusting method, which can make the sound image perceived by a user close to the actual sound image as much as possible, thereby reducing the deviation of the sound image perceived by the user compared with the actual sound image. The pan method can be applied to the headphones described in this application independently, or in combination with the above-described volume compensation scheme and/or embodiment.

Fig. 9 shows a flowchart of a method S100 for adjusting sound image according to an embodiment of the present application. The process S100 may be used to adjust the sound images output by the first and

second speakers

310 and 320 of the sound output device 300. Specifically, the process S100 may include: s110, acquiring a volume difference between the first sound wave and the second sound wave; and S120, adjusting the time difference between the first sound wave and the second sound wave.

The "binaural effect" is an effect in which a person discriminates the sound bearing by the volume difference, time difference, phase difference, and timbre difference between ears. Because there is a certain distance between the left and right ears, except the sounds from the front and back, the volume, time, phase and timbre of the same sound coming from other directions reach the two ears successively, thereby causing volume difference, time difference, phase difference and timbre difference. As an example, if the sound source is to the right, the sound must reach the right ear first and then the left ear. The more the sound is biased to one side, the larger the time difference is. As an example, if the sound source is more to the right, the sound source is closer to the right ear than to the left ear, and the volume reaching the right ear is greater than to the left ear. The more the sound is biased to one side, the larger the sound volume difference. As an example, sound is propagated in the form of waves, while the phases of the sound waves are different at different locations in space. Due to the spatial distance between the ears, there may be a difference in the phase of the sound waves arriving at the ears. The tympanic membrane within the ear membrane vibrates with the sound waves. The phase difference of the vibrations also becomes a factor in the discrimination of the sound source orientation by the brain of the user.

The human brain relies on the "binaural effect" to determine the location of sound sources (i.e., sound images).

If the left ear hears a sound first, the listener's brain perceives the sound as coming from the left (the side from which the sound was heard first), i.e., the sound image perceived by the listener's brain is shifted to the left. And vice versa. This phenomenon is called the "time difference effect" between the left and right ears.

If the left ear hears a sound that is larger than the right ear, then the listener's brain may perceive the sound as coming from the left direction and vice versa. This phenomenon is called "volume difference effect" between the left and right ears. The aforementioned sound image deviation due to the difference between the first mechanical structure mass and the second mechanical structure mass may also be understood as "volume difference effect" per se.

Thus, we can use the "time difference" and/or the "phase difference" to adjust the offset of the sound image perceived by the user due to the "volume difference".

And S110, acquiring the volume difference of the first sound wave and the second sound wave. First, we obtain the volume difference of the first sound wave 21 and the second sound wave 22. From the volume difference, a value of the sound image deviation due to the volume difference can be obtained. For example, if the volume of the first sound wave 21 is smaller than the volume of the second sound wave 22 by β, the sound image perceived by the user is shifted from the centered position by δ toward the second speaker 320.

And S120, adjusting the sound production time difference of the first sound wave and the second sound wave.

In some embodiments, the offset of the sound image perceived by the user due to the difference in the quality of the first mechanical structure 311 and the second mechanical structure may be adjusted by adjusting the time difference between the pronunciations of the first sound wave 21 and the second sound wave 22.

Take the case that the volume of the first sound wave 21 is smaller than the volume of the second sound wave 22. The first time length t is required for the sound output device 300 to convert the target sound information 10 into the first sound waves 21₁(ii) a The sound output device 300 requires the second time length t for converting the target sound information 10 into the second sound wave 22₂(ii) a And the first time length t₁Is shorter than the second time length t₂. Thus, the sound emission time of the first speaker 310 is earlier than the sound emission time of the second speaker 320 for the target sound information 10. In some embodiments, the articulation time of the first speaker 310 is advanced by a time difference from the articulation time of the second speaker 320. In some embodiments, the time difference is no greater than 3 ms. Specifically, the time difference may be any of the following values or any value between any two values: 0.1ms, 0.2ms, 0.3ms, 0.4ms, 0.5ms, 0.6ms, 0.7ms, 0.8ms, 0.9ms, 1.0ms, 1.1ms, 1.2ms, 1.3ms, 1.4ms, 1.5ms, 1.6ms, 1.7ms, 1.8ms, 1.9ms, 2.0ms, 2.1ms, 2.2ms, 2.3ms, 2.4ms, 2.5ms, 2.6ms, 2.7ms, 2.8ms, 2.9ms, 3.0 ms. It is assumed that the first sound wave 21 and the second sound wave 22 are the same except for the utterance time. In the case of the same transmission medium and transmission distance, the first sound wave 21 is heard by the left ear of the user earlier than the second sound wave 22 by the right ear. According to the binaural effect, the brain of the user judges that the source position of the target sound information 10 is biased toward the side of the first sound wave 21 uttered earlier, that is, the left side of the user. In this way, considering the right shift of the sound image caused by the volume of the first sound wave 21 being smaller than the volume of the second sound wave 22, the source position of the target sound information 10 heard by the end user (i.e., the sound image perceived by the user) is also adjusted to the middle position. This solves the problem of the sound image shifting to the right due to the mass of the first mechanical structure 311 being greater than the mass of the second mechanical structure 321.

In some embodiments, the sound image position of the headphones may be adjusted by controlling the time difference of the audio signals of the speakers on both sides (i.e., the time difference of the audio signals of the left and right channels). For example, the sound image position of the headphones can be adjusted by controlling the time difference of the sound waves output from the speakers on both sides. For example, a first sound wave output by the first speaker is advanced relative to a second sound wave output by the second speaker by the action of the first speaker and the action of the second speaker. In some embodiments, the first acoustic wave is advanced by a time difference relative to the second acoustic wave. In some embodiments, the time difference is no greater than 3 ms. Specifically, the time difference may be any of the following values or any value between any two values: 0.1ms, 0.2ms, 0.3ms, 0.4ms, 0.5ms, 0.6ms, 0.7ms, 0.8ms, 0.9ms, 1.0ms, 1.1ms, 1.2ms, 1.3ms, 1.4ms, 1.5ms, 1.6ms, 1.7ms, 1.8ms, 1.9ms, 2.0ms, 2.1ms, 2.2ms, 2.3ms, 2.4ms, 2.5ms, 2.6ms, 2.7ms, 2.8ms, 2.9ms, 3.0 ms. For example, the time difference may be 1.0ms, or a value slightly larger than 1.0 ms.

In some embodiments, the sound image position of the headphones may be adjusted by controlling the time difference of the audio signals input to the speakers on both sides (i.e., the time difference of the first electrical signal and the second electrical signal). For example, the first electrical signal input to the first speaker is advanced relative to the second electrical signal input to the second speaker by the action of the signal processing circuit. In some embodiments, the first electrical signal is advanced by a time difference relative to the second electrical signal. In some embodiments, the time difference is no greater than 3 ms. Specifically, the time difference may be any of the following values or any value between any two values: 0.1ms, 0.2ms, 0.3ms, 0.4ms, 0.5ms, 0.6ms, 0.7ms, 0.8ms, 0.9ms, 1.0ms, 1.1ms, 1.2ms, 1.3ms, 1.4ms, 1.5ms, 1.6ms, 1.7ms, 1.8ms, 1.9ms, 2.0ms, 2.1ms, 2.2ms, 2.3ms, 2.4ms, 2.5ms, 2.6ms, 2.7ms, 2.8ms, 2.9ms, 3.0 ms. For example, the time difference may be 1.0ms, or a value slightly larger than 1.0 ms.

Further, the offset value δ of the user-perceived sound image is obtained, and the user-perceived sound image can also be adjusted by adjusting the phase difference of the first sound wave 21 and the second sound wave 22 to center the user-perceived sound image. As an example, assume that the phase of the first acoustic wave 21 needs to be larger than the phase of the second acoustic wave 22 by δ w₂Can make the sound image orientedThe direction of the first sound wave 21 is shifted by δ.

In order to make the phase of the first sound wave 21 larger than that of the second sound wave 22 by δ w₂We can place a phase delay circuit in the signal processing circuit 330 and/or the first speaker 310 and/or the second speaker 320.

For example, the phase of the first sound wave 21 may be made larger than the phase of the second sound wave 22 by δ w by providing a phase delay circuit in the second speaker 320₂. For example, the signal processing circuit 330 processes the target sound information 10 so that the phases of the generated first electric signal 11 and the second electric signal 12 are the same. A phase delay circuit may be provided in the second speaker 320. The second speaker 320 may delay the phase of the second electrical signal 12 by δ w₂And generates the phase identity delay deltaw₂ Second sound wave 22. That is, the phase of the final first sound wave 21 is larger than the phase of the second sound wave 22 by δ w₂. According to the binaural effect, the sound image perceived by the user is shifted in the direction of the first sound wave 21 having a larger phase. In this way, the mass m due to the first mechanical structure 311 can be counteracted₁Mass m greater than the second mechanical structure 321₂The resulting shift of the sound image to the direction of the second sound wave 22. Eventually, the user perceives the sound image as centered.

For example, the phase delay circuit may be provided in the signal processing circuit 330 so that the phase of the first sound wave 21 is larger than the phase of the second sound wave 22 by δ w₂. For example, the signal processing circuit 330 may process the target sound information 10 to obtain the first electrical signal 11 and the second electrical signal 12. The phase of the first electrical signal 11 is larger than the phase of the second electrical signal 12 by δ w₁. And δ w₁＝δw₂. The first speaker 310 performs the same phase processing on the first electrical signal 11 and the second speaker 320 performs the same phase processing on the phase of the second electrical signal 12 (for example, the first speaker 310 does not perform the phase processing on the first electrical signal 11; and the second speaker 320 does not perform the phase processing on the second electrical signal 12). Thus, the phase of the first sound wave 21 generated by the first speaker 310 is finally larger than the phase of the second sound wave 22 generated by the second speaker 320 by δ w₂. From the binaural effect, the sound image perceived by the user isIt is shifted in the direction of the first sound wave 21 of greater phase. In this way, the mass m due to the first mechanical structure 311 can be counteracted₁Mass m greater than the second mechanical structure 321₂The resulting shift of the sound image to the direction of the second sound wave 22. Eventually, the user perceives the sound image as centered.

In some embodiments, the difference in volume of the first sound wave and the second sound wave is no greater than 3 dB. In this way, the "time difference" and/or the "phase difference" are used to adjust the offset of the sound image perceived by the user due to the "volume difference" and, on the one hand, adjust the sound image perceived by the user without affecting the hearing of the user. This is because the sound image is centered by adjusting the phase difference/time difference, only the sound image perceived by the user is adjusted, and the volumes of the first sound wave and the second sound wave actually heard by the left and right ears are not changed. If the sound volume difference of the sound waves heard by the left ear and the right ear is too large, the ears of a user can be damaged by long-term use.

In summary, the present application provides a sound image adjusting method S100 and a volume adjusting method S200. The sound image adjusting method S100 of the present application includes: s110, acquiring a volume difference between the first sound wave and the second sound wave; and S120, adjusting the sound production time difference of the first sound wave and the second sound wave. The volume adjustment method S200 of the present application includes: s210, acquiring a volume difference between the first sound wave and the second sound wave; and S220, adjusting the amplitude difference of the first excitation and the second excitation. The sound image adjustment method S100 corrects the deviation of the sound image perceived by the user due to the difference in quality between the first mechanical structure and the second mechanical structure by setting the time difference between the first sound wave and the second sound wave. According to the volume adjusting method S200, the volume difference between the first loudspeaker and the second loudspeaker caused by the quality difference of the first mechanical structure and the second mechanical structure is corrected by setting different coil resistivity, coil winding diameter, magnetic field intensity and/or resistance.

As can be seen from the foregoing description: and the sound volume of the sound wave generated by the loudspeaker is positively correlated with the amplitude of the mechanical structure in the loudspeaker when the difference between the transmission medium and the transmission distance is not considered. The greater the amplitude of the mechanical structure, the greater the sound volume of the sound wave. While the amplitude of the mechanical structure is positively correlated to the excitation to which the mechanical structure is subjected. For the same mechanical structure, the greater the excitation to which the mechanical structure is subjected, the greater the amplitude of the mechanical structure.

In some embodiments, the volume of a first sound wave generated by a first mechanical structure and the volume of a second sound wave generated by a second mechanical structure in the sound output device may be different under the same excitation. For example, in the sound output apparatus 300 shown in FIG. 1, the additional device 940 is arranged such that the mass of the first mechanical structure 311 is larger than the mass of the second mechanical structure 321 (i.e., M)₁＞M₂). With reference to equation (6), the amplitude of the vibration of the first mechanical structure is smaller than the amplitude of the vibration of the second mechanical structure at the same excitation f. The volume of the first sound wave perceived by the user is smaller than the volume of the second sound wave, regardless of the difference in the transmission medium and the transmission distance. Of course, in some embodiments, the reason for the difference in the sound volume of the sound waves output from the two ends of the sound output device may be other reasons, for example, the quality of the two ends of a common earphone without a headset microphone may be different due to water inflow or other reasons, and finally, the sound volume of the sound emitted from the two ends of the earphone may also be different. For ease of understanding, in the following description, we will describe a bone conduction speaker as an example.

In practice, in order not to affect the user experience, we need to make the volume of the sound heard by the ears of the user as consistent as possible. As can be seen from the foregoing description, the volume of sound waves generated by a speaker in an acoustic output device is related to the excitation generated based on an electrical signal, the mass M of the mechanical structure generating the vibration, the damping C and the stiffness K of the vibration system, and the like.

For example, taking the bone conduction speaker 100 as an example, according to the formula (6), the volume of the sound wave generated by the bone conduction speaker 100 is simultaneously influenced by the following parameters: frequency of excitation F (magnitude equal to 1/ω), amplitude of excitation F₀Mass m of the housing 120₁Mass m of magnetic circuit 130₂Stiffness k of vibration transmission plate 140₁And damping c₁And the stiffness k of the earhook 110₂And damping c₂. For example, the amplitude F of the excitation F is such that the other parameters remain unchanged₀Amplitude of vibration X with the housing 120₁In a proportional relationship. Amplitude F of excitation F₀The larger the amplitude X of the housing 120₁The larger. As another example, the mass m of the housing 120 of the bone conduction speaker 100 may be maintained constant while maintaining other parameters₁The larger the amplitude X of the housing 120₁The smaller. Thus, when the above parameters are changed, the amplitude X of the housing 120 is changed₁And consequently also changes. Amplitude X of the housing 120 without taking into account differences in transmission media and transmission distances₁Which is positively correlated with the volume of the sound wave generated by the vibration of the housing 120. Amplitude X₁The larger the sound wave, the greater the volume of the sound wave; amplitude X₁The smaller the sound volume of the sound wave.

Thus, if the excitation F and the mass M of the mechanical structure can be reasonably balanced, the desired vibration amplitude X can be obtained. Even if the mechanical structure quality of the two ends of the sound output device is different (for example, a headset is arranged on one side of the bone conduction earphone), the sound volume output by the two ends of the sound output device can be consistent.

Therefore, the application also provides a sound output device. The sound output device may include, but is not limited to, an earphone, a hearing aid, a helmet, and the like. The headset may include, but is not limited to, a wired headset, a wireless headset, a bluetooth headset, and the like. In particular, the sound output device may include a first speaker, a second speaker, and a signal processing circuit.

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

The first speaker is electrically connected with the signal processing circuit. The first speaker may receive a first electrical signal from the signal processing circuit and convert the first electrical signal into a first sound wave. In some embodiments, the first speaker comprises a first bone conduction speaker, and the first sound waves comprise first bone conduction sound waves. In some embodiments, the first speaker may convert the received first electrical signal into mechanical vibrations. Further, the first acoustic wave is generated by the mechanical vibration. In some embodiments, the first loudspeaker may comprise a first mechanical structure and a first excitation means. The first excitation means generates a first excitation based on the first electrical signal. The first excitation excites the first mechanical structure to vibrate as an external force, and further the first mechanical structure vibrates to generate a first sound wave.

The second speaker is electrically connected with the signal processing circuit. The second speaker may receive a second electrical signal from the signal processing circuit and convert the second electrical signal into a second sound wave. In some embodiments, the second speaker comprises a second bone conduction speaker, and the second sound wave comprises a second bone conduction sound wave. In some embodiments, the second speaker may convert the received second electrical signal into mechanical vibrations. Further, the second acoustic wave is generated by the mechanical vibration. In some embodiments, the second speaker may include a second mechanical structure and a second excitation device. The second excitation means generates a second excitation based on the second electrical signal. The second excitation is used as an external force to excite the second mechanical structure to vibrate, and further, the second mechanical structure vibrates to generate a second sound wave.

In some embodiments, the first and second excitation means may be electromagnetic excitation means. The magnitude of the first excitation and the magnitude of the second excitation can be calculated by formula (1); the vibration process of the first mechanical structure and the second mechanical structure can be expressed by formula (6).

For convenience of description, in the following description of the present application, reference will be made to F₁Representing the magnitude of the first excitation by F₂Indicating the magnitude of the second excitation by M₁Representing the mass of the first mechanical structure, in M₂Mass of the second mechanical structure, denoted by S₁The cross-sectional area of the first coil winding is represented by S₂The cross-sectional area of the winding of the second coil is expressed by rho₁Representing the resistivity of the first coil winding in p₂The resistivity of the second coil winding is shown as B₁Indicates the magnetic field strength of the first magnetic member by B₂Indicates the magnetic field strength of the second magnetic member by R₁The resistance of the first coil winding (hereinafter referred to as the first resistance) is represented by R₂The resistance of the second coil winding (hereinafter referred to as the second resistance) is represented by X₁Representing the amplitude of vibration of the first mechanical structure by X₂Representing the amplitude of the vibration of the second mechanical structure.

The volume of sound produced by the first mechanical structure is less than the volume of sound produced by the second mechanical structure for the same stimulus. By way of example, in some embodiments, the mass M of the first mechanical structure₁Mass M greater than the second mechanical structure₂The volume of a first sound wave generated by the vibration of the first mechanical structure under the same excitation is smaller than the volume of a second sound wave generated by the vibration of the second mechanical structure. Referring to equation (1) and equation (6), we assume that the first electrical signal and the second electrical signal are the same (U)₁＝U₂) And the first and second excitation means are the same (i.e. B)₁＝B₂，S₁＝S₂，ρ₁＝ρ₂，R₁＝R₂) Irrespective of differences in damping and stiffness (i.e. C)₁＝C₂，K₁＝K₂) Then, from equation (1) and equation (6), the first excitation F can be derived₁And a second excitation F₂Same (F)₁＝F₂). Based on the above assumptions, since M₁＞M₂According to the relation between the mass and the amplitude, the amplitude of the vibration of the first mechanical structure is smaller than that of the vibration of the second mechanical structure. In the case of the same propagation medium and propagation distance, the volume of the sound wave emitted by the first speaker heard by the user is smaller than the volume of the sound wave emitted by the second speaker.

The volume of the first sound wave is the same as the volume of the second sound wave.

For convenience of description, the left ear and the right ear of the user hear the first sound wave and the second sound wave, respectively. Generally, it is desirable that the volume of the first sound wave heard by the left ear of the user is as same as the volume of the second sound wave heard by the right ear as possible, so as to avoid the damage to both ears caused by the volume difference. That is, in the case where the transmission distance and the transmission medium are the same, it is desirable that the amplitude of the vibration of the first mechanical structure and the amplitude of the vibration of the second mechanical structure coincide as much as possible.

In some embodiments, the diameter of the first coil wire is greater than the diameter of the second coil wire, i.e., S₁＞S₂. The first excitation F generated by the first excitation means is according to the equations (1) and (6)₁Greater than a second excitation F produced by the second excitation means₂Thus, X can be made₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave is the same as the power of the second sound wave, and the volume of the first sound wave heard by the user is the same as the volume of the second sound wave. This corrects for differences in mass (M) due to the first and second mechanical structures₁＞M₂) Resulting in a volume difference.

In some embodiments, the resistivity of the first coil is less than the resistivity of the second coil, i.e., ρ₁＜ρ₂. The first excitation F generated by the first excitation means is according to the equations (1) and (6)₁Greater than a second excitation F produced by the second excitation means₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave is the same as the power of the second sound wave, and the volume of the first sound heard by the user is the same as the volume of the second sound wave. This corrects for differences in sound volume due to differences in mass of the first and second mechanical structures.

In some embodiments, the magnetic field strength B generated by the first electromagnetic excitation device is the same at the same input current₁Is greater than the magnetic field intensity B generated by the second electromagnetic excitation device₂. The second excitation F generated by the first excitation means is according to the equations (1) and (6)₁Greater than a second excitation F produced by the second excitation means₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave is the same as the power of the second sound wave, and the volume of the first sound wave heard by the user is the same as the volume of the second sound wave. This corrects for the sound due to the difference in mass between the first and second mechanical structureThe difference in amount. In some embodiments, the remanence of the first magnetic member is greater than the remanence of the second magnetic member such that the first electromagnetic excitation device generates a magnetic field strength B₁Is greater than the magnetic field intensity B generated by the second electromagnetic excitation device₂. In some embodiments, the coercivity of the first magnetic member is greater than the coercivity of the second magnetic member such that the magnetic field strength B generated by the first electromagnetic excitation device is greater₁Is greater than the magnetic field intensity B generated by the second electromagnetic excitation device₂. In some embodiments, the magnetic energy product of the first magnetic member is greater than the magnetic energy product of the second magnetic member, so that the magnetic field intensity B generated by the first electromagnetic excitation device is larger than the magnetic energy product of the second magnetic member₁Is greater than the magnetic field intensity B generated by the second electromagnetic excitation device₂。

In some embodiments, the first resistance R₁Is less than the second resistance R₂. The first excitation F generated by the first excitation means is according to the equations (1) and (6)₁Greater than a second excitation F produced by the second excitation means₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave is the same as the power of the second sound wave, and the volume of the first sound wave heard by the user is the same as the volume of the second sound wave. This corrects for differences in sound volume due to differences in mass of the first and second mechanical structures.

In some embodiments, the first resistance R may be achieved by connecting a resistor in series outside the second coil₁Is less than the second resistance R₂And further corrects the difference in volume due to the difference in mass between the first mechanical structure and the second mechanical structure.

In some embodiments, the resistance R of the first coil may be reduced₁And/or increasing the resistance R of the second coil₂So that the first resistor R₁Is less than the second resistance R₂And further corrects the difference in volume due to the difference in mass between the first mechanical structure and the second mechanical structure.

According to the formula R ═ pl/S, in some embodiments, the resistance of the first coil can be made smaller than the resistance of the second coil by increasing the resistivity of the first coil and/or decreasing the resistivity of the second coil.

According to the formula R ═ pl/S, in some embodiments, the resistance of the first coil may be made smaller than the resistance of the second coil by increasing the length of the wire of the first coil and/or decreasing the length of the wire of the second coil.

According to the formula R ═ pl/S, in some embodiments, the resistance of the first coil can be made smaller than the resistance of the second coil by decreasing the diameter of the wire of the first coil and/or increasing the diameter of the wire of the second coil.

It should be noted that the mass of the first coil and/or the second coil may also change when the resistivity, the winding length and/or the winding diameter of the first coil and/or the second coil are increased and/or decreased. The mass of the coil will also have an influence on the vibrations of the first mechanical structure. Therefore, when adjusting parameters such as resistivity, winding length and/or winding diameter, we need to consider the influence of other parameters to make the amplitude of the vibration of the final first mechanical structure consistent with the amplitude of the vibration of the second mechanical structure.

In some embodiments, a power amplification circuit may be provided in the sound output device. The power amplification circuit may be disposed between the first speaker and the signal processing circuit. The first electric signal output by the signal processing circuit passes through the power amplifying circuit. The power amplification circuit amplifies the first electric signal and outputs the first electric signal to the first loudspeaker. The first speaker receives the amplified first electrical signal. Thus, the first excitation F generated by the first loudspeaker₁Will be larger than the second excitation F generated by the second loudspeaker₂Size of (i.e. F)₁＞F₂). In combination with equation (6), the first excitation F₁Greater than the second excitation F₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave is the same as the power of the second sound wave, and the volume of the first sound wave heard by the user is the same as the volume of the second sound wave. This corrects for differences in sound volume due to differences in mass of the first and second mechanical structures.

In some embodiments of the present invention, the,the sound output device may be provided with a power attenuation circuit. The power attenuation circuit may be disposed between the second speaker and the signal processing circuit. The second electric signal output by the signal processing circuit passes through the power attenuation circuit. The power attenuation circuit attenuates the second electric signal and outputs the second electric signal to the second loudspeaker. The second speaker receives the attenuated second electrical signal. Thus, a second excitation F is generated by the second loudspeaker₂Will be smaller than the first excitation F generated by the first loudspeaker₁Size of (i.e. F)₁＞F₂). In combination with equation (6), the first excitation F₁Greater than the second excitation F₂Can make X₁Is the same as X₂And (5) the consistency is achieved. Then, the power of the first sound wave is the same as the power of the second sound wave, and the volume of the first sound wave heard by the user is the same as the volume of the second sound wave. This corrects for differences in sound volume due to differences in mass of the first and second mechanical structures.

According to the foregoing description, when a difference in sound volume occurs at both ends of the headphone, the sound image felt by the user may be offset. Therefore, it is necessary to design the sound output device so that the sound image output by the sound output device is not shifted as much as possible.

For convenience of description, in the following description of the present application, reference will be made to F₁Representing the magnitude of the first excitation by F₂Indicating the magnitude of the second excitation by M₁Representing the mass of the first mechanical structure, in M₂Mass of the second mechanical structure, denoted by S₁The cross-sectional area of the first coil winding is represented by S₂The cross-sectional area of the winding of the second coil is expressed by rho₁Represents the firstResistivity of coil windings in rho₂The resistivity of the second coil winding is shown as B₁Indicates the magnetic field strength of the first magnetic member by B₂Indicates the magnetic field strength of the second magnetic member by R₁The resistance of the first coil winding (hereinafter referred to as the first resistance) is represented by R₂The resistance of the second coil winding (hereinafter referred to as the second resistance) is represented by X₁Representing the amplitude of vibration of the first mechanical structure by X₂Representing the amplitude of the vibration of the second mechanical structure.

Under the condition of the input of electric signals with the same amplitude and frequency, the volume of the sound wave output by the first loudspeaker is smaller than that of the sound wave output by the second loudspeaker. By way of example, in some embodiments, the mass M of the first mechanical structure₁Mass M greater than the second mechanical structure₂Resulting in a volume of sound waves output by the first speaker being less than a volume of sound waves output by the second speaker at the same magnitude and frequency of electrical signal input. Referring to equations (1) and (6), we assume that the first and second electrical signals are the same in both amplitude and frequency (i.e., U)₁＝U₂) And the first and second excitation means are the same (i.e. B)₁＝B₂，S₁＝S₂，ρ₁＝ρ₂，R₁＝R₂) Irrespective of differences in damping and stiffness (i.e. C)₁＝C₂，K₁＝K₂) Then, according to equation 1) and equation (6), the first excitation F can be derived₁And a second excitation F₂Same (F)₁＝F₂). Based on the above assumptions, since M₁＞M₂According to the relation between the mass and the amplitude, the amplitude of the vibration of the first mechanical structure is smaller than that of the vibration of the second mechanical structure. In the case of the same propagation medium and propagation distance, the volume of the sound wave emitted by the first speaker heard by the user is smaller than the volume of the sound wave emitted by the second speaker. As an example, the difference between the volume of the first sound wave and the volume of the second sound wave is no more than 3dB under the input of electrical signals of the same magnitude and frequency.

For convenience of explanation, in the following description of the present application, the perception of the target sound information by the user is described by taking the example that the first sound wave is transmitted to the left ear of the user and the second sound wave is transmitted to the right ear of the user. Assuming that the first sound wave and the second sound wave are the same except for the sound volume, the sound volume of the first sound wave heard by the left ear of the user is smaller than the sound volume of the second sound wave heard by the right ear of the user according to the binaural effect, then the brain of the user may determine that the sound emission position of the target sound information (i.e., the sound image perceived by the user) is shifted to the right side, i.e., the side of the second sound wave with the larger sound volume.

According to the binaural effect, the sound image shift due to the "sound volume difference" can be solved using the "phase difference" and/or the "time difference".

In some embodiments, the first time length t is required for the sound output device 300 to convert the target sound information 10 into the first sound waves 21₁The second time length t is required for converting the target sound information 10 into the second sound wave 22₂A first time length t₁Is longer than the second time length t₂One time difference deltat shorter. Thus, the sound emission time of the first speaker 310 is advanced by the time difference δ t with respect to the target sound information 10 from the sound emission time of the second speaker 320. In some embodiments, the time difference δ t is not greater than 3 ms. Specifically, the time difference δ t may be any of the following values or any value between any two values: 0.1ms, 0.2ms, 0.3ms, 0.4ms, 0.5ms, 0.6ms, 0.7ms, 0.8ms, 0.9ms, 1.0ms, 1.1ms, 1.2ms, 1.3ms, 1.4ms, 1.5ms, 1.6ms, 1.7ms, 1.8ms, 1.9ms, 2.0ms, 2.1ms, 2.2ms, 2.3ms, 2.4ms, 2.5ms, 2.6ms, 2.7ms, 2.8ms, 2.9ms, 3.0 ms. For example, the time difference δ t may be 1.0ms, or a value slightly larger than 1.0 ms. It is assumed that the first sound wave 21 and the second sound wave 22 are the same except for the utterance time. In the case of the same transmission medium and transmission distance, the first sound wave 21 is heard by the left ear of the user earlier than the second sound wave 22 by the right ear. According to the binaural effect, the source position of the target sound information 10 heard by the user (i.e., the sound image perceived by the user) is corrected.

In some embodiments, the time difference occurs during the conversion of the first electrical signal into the first sound wave by the first speaker and the conversion of the second electrical signal into the second sound wave by the second speaker. For example, a time advance circuit may be provided in the first speaker and/or a time delay circuit may be provided in the second speaker such that the first sound wave output by the first speaker is advanced relative to the second sound wave output by the second speaker. In some embodiments, the first acoustic wave is advanced by a time difference δ t from the second acoustic wave.

In some embodiments, the time difference occurs during the process in which the sound output device converts the target sound information into the first electrical signal and the second electrical signal. For example, a time processing circuit may be provided in the signal processing circuit so that the first electric signal input to the first speaker is advanced in advance of the second electric signal input to the second speaker. In some embodiments, the first electrical signal is advanced by a time difference δ t relative to the second electrical signal.

In some embodiments, there is a first phase difference δ w between the second sound wave and the first sound wave₁. In some embodiments, the phase of the first sound wave is δ w greater than the phase of the second sound wave₁. Assuming that the first sound wave and the second sound wave are the same except for the phase, the brain of the user may determine that the position of the source of the target sound information (i.e., the sound image perceived by the user) is biased toward the side of the first sound wave with the larger phase, i.e., the left side of the user, according to the binaural effect. In this way, considering that the sound image is shifted to the right by the volume of the first sound wave being smaller than the volume of the second sound wave, eventually, the source position of the target sound information heard by the user is adjusted to the middle position. This solves the sound image shift caused by the mass of the first mechanical structure being greater than the mass of the second mechanical structure.

In some embodiments, the second electrical signal is in phase with the first electrical signal. As an example, the signal processing circuit may process the target sound information so that the generated first electrical signal and the second electrical signal have the same phase. Further, a phase delay circuit may be provided in the second speaker. The phase delay circuit may delay the phase of the second electrical signal by δ w₁And generates the phase identity delay deltaw₁The second acoustic wave of (1). Thus, the phase of the first sound wave can be made larger than the phase of the second sound wave by δ w₁. In this way, it is possible to solve the sound image shift caused by the mass of the first mechanical structure being larger than that of the second mechanical structure.

In some embodiments, the second electrical signal has a second phase difference δ w with the first electrical signal₂(ii) a And a second phase difference δ w₂Is out of phase with the first phase delta w₁The same is true. As an example, a phase delay circuit may be provided in the signal processing circuit. The signal processing circuit may process the target sound information to obtain a first electrical signal and a second electrical signal. And a second phase difference deltaw is provided between the first electric signal and the second electric signal₂. For example, the phase of the first electrical signal is δ w greater than the phase of the second electrical signal₂. The first and second speakers do not change the phase of the first electrical signal and the phase of the second electrical signal so that the first sound wave generated by the first speaker is greater in phase by δ w than the second sound wave generated by the second speaker₂. And δ w₂Same delta w₁Also, that is, finally, the phase of the first sound wave is larger than the phase of the second sound wave by δ w₁. This also makes it possible to solve the sound image shift caused by the mass of the first mechanical structure being greater than that of the second mechanical structure.

Thus, the sound emission time of the first speaker is earlier than the sound emission time of the second speaker with respect to the target sound information. It is assumed that the first sound wave and the second sound wave are the same except for the utterance time. In the case of the same transmission medium and transmission distance, the first sound wave is heard by the left ear of the user at a time earlier than the second sound wave is heard by the right ear. According to the binaural effect, the brain of the user judges that the source position of the target sound information is biased toward the side of the first sound wave uttered earlier, that is, the left side of the user. In this way, considering the right shift of the sound image caused by the volume of the first sound wave being smaller than the volume of the second sound wave, the source position of the target sound information heard by the end user (i.e., the sound image perceived by the user) is also adjusted to the middle position. This solves the problem of the sound image shifting to the right due to the mass of the first mechanical structure being greater than the mass of the second mechanical structure.

In summary, the present application provides a sound image adjusting method S100, a volume adjusting method S200 and two sound output devices. The sound image adjusting method S100 of the present application includes: s110, acquiring a volume difference between the first sound wave and the second sound wave; and S120, adjusting the sound production time difference of the first sound wave and the second sound wave. The volume adjustment method S200 of the present application includes: s210, acquiring a volume difference between the first sound wave and the second sound wave; and S220, adjusting the amplitude difference of the first excitation and the second excitation. The sound output apparatus and the sound image adjusting method S100 of the present application correct the deviation of the sound image perceived by the user due to the difference in the quality of the first mechanical structure and the second mechanical structure by setting the time difference between the first sound wave and the second sound wave. The sound output device and the sound volume adjusting method correct the sound volume difference between the first loudspeaker and the second loudspeaker caused by the quality difference of the first mechanical structure and the second mechanical structure by setting different coil resistivity, coil winding diameter, magnetic field intensity and/or resistance.

It should be noted that the propagation medium of the first acoustic wave and/or the second acoustic wave described in the present application does not limit the scope of the present application. The first and/or second acoustic waves may be propagated through a solid (e.g., bone) or through a gas (e.g., air). In some embodiments, the propagation medium may include one or a combination of air and bone.

It should be noted that, in actual design and production, the volume adjusting method, the sound image adjusting method, and the sound output device described in the present application may be used in combination to achieve a desired adjusting effect. For example, in some embodiments, the sound image adjustment method S100 may be used alone to adjust the sound image output by the sound output device. For example, in some embodiments, the sound image and the volume of the sound output by the sound output device may be adjusted using both the volume adjustment method S200 and the sound image adjustment method S100.

For example, mass adjustment and excitation adjustment may be performed simultaneously. For example, when M₁＞M₂When the first and

second speakers

310 and 320 are tuned to each other, the "mass of the second mechanical structure 311", "first excitation", "diameter of the first coil", and the like may be used.

For example, when M₁＞M₂When the first and

second speakers

310 and 320 are operated in the same manner, the "mass of the second mechanical structure 311" is increased "," first excitation is increased "," diameter of the second coil is decreased ", and the like, may be used simultaneously to keep the volume difference between the first and

second speakers

310 and 320 within the target volume difference range; thereafter, the method of setting the phase difference may be simultaneously employed to adjust the sound image.

It should be noted that the description of the present application of keeping the volume of the first speaker and the volume of the second speaker "consistent" or "the same" is only for the purpose of analysis and does not limit the scope of protection of the present application. The keeping of the volume of the first speaker and the volume of the second speaker to be the same or the same may be keeping the volume difference between the first speaker and the second speaker within a target volume difference range.

It should be noted that the "centering" of the sound image of the sound output device is described herein for the purpose of analysis only, and does not limit the scope of the present invention. The centering of the sound image may be maintaining the sound image within a target position range.

In conclusion, upon reading the present detailed disclosure, those skilled in the art will appreciate that the foregoing detailed disclosure can be presented by way of example only, and not limitation. Those skilled in the art will appreciate that the present application is intended to cover various reasonable variations, adaptations, and modifications of the embodiments described herein, although not explicitly described herein. Such alterations, improvements, and modifications are intended to be suggested by this disclosure, and are within the spirit and scope of the exemplary embodiments of this disclosure.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. For example, as used herein, the singular forms "a", "an", "the" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and/or "including," when used in this specification, mean that the associated integers, steps, operations, elements, and/or components are present, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "A on B" means that A is either directly adjacent (above or below) B or indirectly adjacent (i.e., separated by some material) to B; the term "A within B" means that A is either entirely within B or partially within B.

Furthermore, certain terminology has been used in this application to describe embodiments of the disclosure. For example, "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present disclosure. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined as suitable in one or more embodiments of the disclosure.

It should be appreciated that in the foregoing description of embodiments of the disclosure, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of the subject disclosure. This application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains. This is not to be taken as an admission that any of the features of the claims are essential, and it is fully possible for a person skilled in the art to extract some of them as separate embodiments when reading the present application. That is, embodiments in the present application may also be understood as an integration of multiple sub-embodiments. And each sub-embodiment described herein is equally applicable to less than all features of a single foregoing disclosed embodiment.

In some embodiments, numbers expressing quantities or properties useful for describing and claiming certain embodiments of the present application are to be understood as being modified in certain instances by the terms "about", "approximately" or "substantially". For example, "about", "approximately" or "substantially" may mean a ± 20% variation of the value it describes, unless otherwise specified. Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the embodiments of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as possible.

Each patent, patent application, publication of a patent application, and other material, such as articles, books, descriptions, publications, documents, articles, and the like, cited herein is hereby incorporated by reference. All matters hithertofore set forth herein except as related to any prosecution history, may be inconsistent or conflicting with this document or any prosecution history which may have a limiting effect on the broadest scope of the claims. Now or later associated with this document. For example, if there is any inconsistency or conflict in the description, definition, and/or use of terms associated with any of the contained materials with respect to the description, definition, and/or use of terms associated with this document, the terms in this document shall prevail.

Finally, it should be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the present application. Other modified embodiments are also within the scope of the present application. Accordingly, the disclosed embodiments are presented by way of example only, and not limitation. Those skilled in the art can implement the invention in the present application in alternative configurations according to the embodiments in the present application. Thus, embodiments of the present application are not limited to those embodiments described with precision in the application.

Claims

1. An audio output device, comprising:

a signal processing circuit operable to generate a first electrical signal and a second electrical signal based on target sound information;

the first loudspeaker is electrically connected with the signal processing circuit, and is used for receiving a first electric signal from the signal processing circuit during operation and converting the first electric signal into a first sound wave; and

a second speaker electrically connected to the signal processing circuit, for receiving a second electrical signal from the signal processing circuit and converting the second electrical signal into a second sound wave during operation, wherein

The sound output device requires a first length of time to convert the target sound information into the first sound wave, requires a second length of time to convert the target sound information into the second sound wave,

the first length of time is shorter than the second length of time by a time difference.

2. The sound output device of 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 at the same magnitude and frequency of the electrical signal input.

3. The sound output apparatus according to claim 2, wherein the difference between the volume of the first sound wave and the volume of the second sound wave is not more than 3dB under the input of electrical signals of the same magnitude and frequency.

4. The acoustic output apparatus of claim 2, wherein the first speaker generates the first acoustic wave by exciting a first mechanical structure; and

the second speaker generates a second acoustic wave by exciting a second mechanical structure, wherein

The mass of the first mechanical structure is greater than the mass of the second mechanical structure, resulting in a volume of sound waves output by the first speaker being less than a volume of sound waves output by the second speaker at the same magnitude and frequency of electrical signal input.

5. The sound output device of claim 2, wherein the first speaker comprises 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.

6. The sound output device according to claim 1, wherein the time difference occurs during a process in which the sound output device converts the target sound information into the first electric signal and the second electric signal.

7. The sound output apparatus according to claim 1, wherein the time difference occurs during a process in which the first speaker converts the first electric signal into the first sound wave and the second speaker converts the second electric signal into the second sound wave.

8. The sound output device of claim 1, wherein the time difference is not greater than 3 ms.

9. A method of adjusting sound images, configured to adjust sound images of the first speaker and the second speaker of the sound output apparatus according to any one of claims 1 to 8, comprising:

acquiring a volume difference between the first sound wave and the second sound wave; and

adjusting the time difference.

10. The method of adjusting sound image according to claim 9, wherein the difference in sound volume between the first sound wave and the second sound wave is not more than 3 dB.

11. The method of adjusting sound image according to claim 9, wherein the adjusting the time difference of the first sound wave and the second sound wave comprises:

adjusting a phase difference of the first sound wave and the second sound wave.