Acoustic output equipment

Abstract

The embodiment of the invention provides acoustic output equipment. The acoustic output equipment comprises a shell; the bone conduction vibrator is used for generating bone conduction sound waves and transmitting the sound waves to the cochlea through the shell to generate sound; the air conduction oscillator is used for generating air conduction sound waves, and the air conduction sound waves are transmitted to the ear parts through sound conduction holes in the shell; the signal processing module is used for providing a first audio signal and a second audio signal for the bone conduction oscillator and the air conduction oscillator respectively, the first audio signal and the second audio signal are provided with frequency division points, and the first audio signal and the second audio signal respectively comprise components with frequencies above and below the frequency division points, the bone conduction oscillator has a first harmonic peak at a first resonant frequency, the air conduction oscillator has a second harmonic peak at a second resonant frequency, and the frequency division point is larger than the first resonant frequency and the second resonant frequency.

Description

Cross-references

[0001] This application claims priority to Chinese application No. 202311427342.7 filed on October 27, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present specification relates to the field of acoustic technology, and in particular to an acoustic output device. Background Art

[0003] The bone-air conduction combined acoustic output device uses the air conduction vibrator to mainly provide low frequencies, and the bone conduction vibrator to mainly provide high frequencies, which can reduce the vibration caused by the vibration of the bone conduction vibrator and improve the user experience. The bone-air conduction combined acoustic output device sets the crossover point of the bone and air conduction audio signals (i.e., electrical signals) so that the bone and air conduction vibrators each generate sound waves with different main working frequency ranges. In actual applications, there may be a certain frequency overlap between the bone and air conduction audio signals near the crossover point, resulting in overlap of the bone and air conduction sound waves generated by the bone and air conduction vibrators. At this time, the bone and air conduction sound waves may be anti-phased and canceled within the overlapping frequency range, thereby affecting the acoustic effect of the acoustic output device.

[0004] Therefore, it is necessary to propose an acoustic output device that can avoid the adverse effects caused by the interaction of bone- and air-conducted audio signals near the crossover point, so as to improve the acoustic effect of the acoustic output device. Summary of the invention

[0005] One of the embodiments of the present specification provides an acoustic output device, including: a shell; a bone conduction vibrator, which is used to generate bone conduction sound waves and transmit them to the cochlea through the shell to generate sound; an air conduction vibrator, which is used to generate air conduction sound waves, and the air conduction sound waves are transmitted to the ear through the sound guide holes on the shell; a signal processing module, which is used to provide a first audio signal and a second audio signal to the bone conduction vibrator and the air conduction vibrator respectively, the first audio signal and the second audio signal have a crossover point, and the first audio signal and the second audio signal respectively include components with frequencies above and below the crossover point, wherein the bone conduction vibrator has a first resonance peak at the first resonance frequency, the air conduction vibrator has a second resonance peak at the second resonance frequency, and the crossover point is greater than the first resonance frequency and the second resonance frequency. By making the crossover point greater than the first resonant frequency and the second resonant frequency, the crossover point can be located within a relatively stable phase range in the phase curves of the bone and air conduction oscillators, so as to ensure that the phases of the bone and air conduction sound waves near the crossover point tend to be stable, and it is easier to ensure that the phases of the bone conduction sound waves and the air conduction sound waves are the same, ensuring that the sound signal near the crossover point does not suddenly drop relative to the frequency bands before and after it, thereby achieving the "superposition" of the bone and air conduction sound waves near the crossover point, producing an effect of in-phase enhancement, and thus improving the acoustic effect of the acoustic output device.

[0006] In some embodiments, the first resonant frequency is between the second resonant frequency and the crossover point. By making the second resonant frequency lower than the first resonant frequency, it is possible to ensure that the air conduction vibrator can have a relatively large output in a lower frequency range, thereby ensuring that the low-frequency output of the air conduction vibrator can cover a wider low-frequency range, so that the acoustic output device can ensure a higher acoustic output in a wider frequency range.

[0007] In some embodiments, the difference between the first resonant frequency and the second resonant frequency and the crossover point is not less than 100 Hz. By making the difference between the first resonant frequency and the second resonant frequency and the crossover point meet a certain threshold range, it is helpful to ensure that the phase of the sound wave in the frequency band near the crossover point is in a stable range, and further avoid the different phases of the bone and air sound waves in the frequency band near the crossover point, thereby ensuring the output performance of the acoustic output device and improving the output stability of the prepared acoustic output device.

[0008] In some embodiments, at the crossover point, the phase difference between the first audio signal and the second audio signal does not exceed 30°, so that the phases of the first audio signal and the second audio signal are relatively close, thereby making the phase of the bone conduction sound wave output by the bone conduction vibrator close to the phase of the air conduction sound wave output by the air conduction vibrator, so as to achieve "superposition" of bone and air conduction sound waves and produce an effect of in-phase enhancement.

[0009] In some embodiments, the crossover frequency is not less than 300 Hz. By setting the crossover frequency to be not less than 300 Hz, the bone conduction vibrator is prevented from generating more low-frequency vibrations, thereby preventing the vibration from being too strong and giving the user a poor experience, thereby ensuring the low-frequency performance of the acoustic output device.

[0010] In some embodiments, the housing includes two sound guide holes, which are used to guide air-conducted sound waves. The difference in the sound amplitude radiated through the two sound guide holes is less than 6 dB, and the phase difference is 150°-210°. At this time, the two sound guide holes form a dipole output structure, and the air-conducted vibrator can radiate sounds of equal amplitude and opposite phase to the outside world through the two sound guide holes, thereby reducing the sound leakage of the air-conducted vibrator in the far field, thereby improving the user's listening and listening privacy.

[0011] In some embodiments, the difference in acoustic loads of the two sound guide holes is less than 0.15. By adjusting the difference range of the acoustic loads of the two sound guide holes, the acoustic impedances of the two sound guide holes are made closer, thereby reducing the near-field sound pressure level difference of the two sound guide holes, so that a dipole or a quasi-dipole can be constructed, thereby improving the effect of reducing far-field leakage sound.

[0012] In some embodiments, the ratio of the surface acoustic loads of the two sound guide holes is 0.5-3.5. By adjusting the surface acoustic load ratio of the two sound guide holes, the acoustic impedances of the two sound guide holes are made closer, thereby reducing the near-field sound pressure level difference of the two sound guide holes, so that a dipole or a quasi-dipole can be constructed, thereby improving the effect of reducing far-field leakage sound.

[0013] In some embodiments, the air conduction vibrator has a front cavity or a rear cavity, the front cavity or the rear cavity forms a third resonance peak with a third resonance frequency, and the crossover point is less than the third resonance frequency. By making the crossover point less than the third resonance frequency, the crossover point can be avoided from the frequency band where the air conduction vibrator has a complex vibration mode, so as to avoid the effect of the dipole formed by the air conduction vibrator through the two sound guide holes being deteriorated, and the sound leakage cannot be effectively reduced, and at the same time, the phase of the sound waves output by the air conduction vibrator and the bone conduction vibrator is not stable enough and it is difficult to keep the two in phase.

[0014] In some embodiments, the difference between the third resonant frequency and the crossover point is not less than 500 Hz. By limiting the difference between the third resonant frequency and the crossover point to not less than 500 Hz, it is helpful to ensure that the phase of the sound wave in the frequency band near the crossover point is in a relatively stable range, and further avoid the different phases of the bone and air sound waves in the frequency band near the crossover point, thereby ensuring the output performance of the acoustic output device and improving the output stability of the prepared acoustic output device.

[0015] In some embodiments, the crossover frequency point is not higher than 3000 Hz, so that the two sound guide holes can stably maintain a phase difference of 180° (or close to 180°) to ensure the sound leakage reduction effect of the air conduction oscillator.

[0016] In some embodiments, the signal processing module performs high-pass filtering and low-pass filtering on the electrical signal containing the sound information to obtain the first audio signal and the second audio signal respectively.

[0017] One of the embodiments of the present specification also provides an acoustic output device, including: a shell; a bone conduction vibrator, which is used to generate bone conduction sound waves and transmit them to the cochlea through the shell to generate sound; an air conduction vibrator, which is used to generate air conduction sound waves, which are transmitted to the ear through the sound guide hole on the shell; a signal processing module, which is used to provide a first audio signal and a second audio signal to the bone conduction vibrator and the air conduction vibrator respectively, the first audio signal and the second audio signal have a crossover point, and the first audio signal and the second audio signal respectively include components with frequencies above and below the crossover point, wherein the air conduction vibrator has a front cavity or a rear cavity, the front cavity or the rear cavity forms a third resonance peak with a third resonance frequency, and the crossover point is less than the third resonance frequency. By making the crossover point less than the third resonance frequency, the crossover point can be avoided from the frequency band where the air conduction vibrator has a complex vibration mode, so as to avoid the effect of the dipole formed by the air conduction vibrator through the two sound guide holes becoming worse, and the sound leakage cannot be effectively reduced, and at the same time, the sound wave phase output by the air conduction vibrator and the bone conduction vibrator is not stable enough and it is difficult to keep the two in phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0019] Figure 1 is a schematic diagram of an exemplary acoustic output device according to some embodiments of the present specification;

[0020] Figure 2 is a schematic diagram of the structure of the connection part between the core assembly and the ear hook assembly according to some embodiments of this specification;

[0021] Figure 3 yes Figure 2 Schematic diagram of the explosion of the structure of the middle movement assembly;

[0022] Figure 4 is a block diagram of an exemplary acoustic output device according to some embodiments of the present specification;

[0023] Figure 5 is a block diagram of another exemplary acoustic output device according to some embodiments of the present specification;

[0024] Figure 6 It is a schematic diagram of the frequency response curve and phase curve of the bone conduction vibrator and the air conduction vibrator according to some embodiments of this specification;

[0025] Figure 7 is a schematic diagram of frequency division points according to some embodiments of this specification;

[0026] Figure 8is a cross-sectional schematic diagram of a movement assembly in the BB section direction according to some embodiments of this specification;

[0027] Fig. 9 is an exemplary acoustic field diagram of a dipole according to some embodiments of this specification;

[0028] Fig.10 is a schematic diagram of an exemplary radiation directional sound field of an acoustic output device according to some embodiments of this specification;

[0029] Fig.11 It is a schematic diagram of a frequency response curve and a corresponding phase curve of an acoustic signal output from two sound-conducting holes coupled to the front and rear cavities of an air-conducting oscillator according to some embodiments of the present specification. DETAILED DESCRIPTION

[0030] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0031] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0032] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0033] In the description of this specification, it should be understood that the terms "first", "second", "third", "fourth", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first", "second", "third", "fourth" may explicitly or implicitly include at least one of the features. In the description of this specification, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0034] In this specification, unless otherwise clearly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense. For example, the term "connection" can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium, it can refer to the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this specification can be understood according to the specific circumstances.

[0035] Figure 1 is a schematic diagram of an exemplary acoustic output device according to some embodiments of the present specification.

[0036] Some embodiments of the present specification provide an acoustic output device 100. Figure 1 As shown, the acoustic output device 100 may include a core component 1, an ear hook component 2 and a back hook component 3. In some embodiments, the number of core components 1 is two. The two core components 1 are used to transmit vibration and / or sound to the left ear and the right ear of the user, respectively, wherein the two core components 1 may be the same or different. For example, a core component 1 may be provided with a microphone, while the other core component 1 may not be provided with a microphone. For another example, a core component 1 may be provided with a button and a corresponding circuit board, while the other core component 1 may not be provided with the button and the corresponding circuit board. The two core components 1 may be the same on the core module (such as a speaker module). This article will be described in detail later by taking one of the two core components 1 as an example. The number of ear hook components 2 may be two, and the two ear hook components 2 may be respectively hung on the left ear and the right ear of the user, so that the core component 1 can fit the user's face. Exemplarily, a battery may be provided at one ear hook component 2, and a control circuit may be provided at the other ear hook component 2. Among them, one end of the ear hook component 2 is connected to the core component 1, and the other end of the ear hook component 2 is connected to the back hook component 3. The back hook component 3 connects the two ear hook components 2, and the back hook component 3 is used to wrap around the back of the user's neck or the back of the head, and can provide a clamping force, so that the two core components 1 are clamped on both sides of the user's face and the ear hook components 2 are more firmly hung on the user's ears.

[0037] It should be noted that, in some embodiments, the acoustic output device 100 may not include a rear hanging component 3. In this case, the acoustic output device 100 may include a core component 1 and an ear hook component 2. One end of the ear hook component 2 may be connected to the core component 1, and the other end thereof extends along the junction of the user's ear and head. In some embodiments, the ear hook component 2 may be an arc-shaped structure adapted to the user's auricle so that the ear hook component 2 is suspended on the user's auricle. For example, the ear hook component 2 may have an arc-shaped structure adapted to the junction of the user's head and ear so that the ear hook component 2 may be hung between the user's auricle and the head. In some embodiments, the ear hook component 2 may also be a clamping structure adapted to the user's auricle so that the ear hook component 2 may be clamped at the user's auricle. Exemplarily, the ear hook component 2 may include a hook-shaped portion and a connecting portion connected in sequence. Among them, the connecting portion connects the hook-shaped portion and the core component 1 so that the acoustic output device 100 is curved in three-dimensional space when it is in a non-wearing state (that is, a natural state). In other words, in three-dimensional space, the hook portion, the connecting portion, and the movement assembly 1 are not coplanar. With such a configuration, when the acoustic output device 100 is in a worn state, the hook portion can be mainly used to hang between the back side of the user's ear and the head, and the movement assembly 1 can be mainly used to contact the front side of the user's ear or the user's head, thereby allowing the movement assembly 1 and the hook portion to cooperate to be clamped on the ear. As an example, the connecting portion can extend from the head to the outside of the head, and then cooperate with the hook portion to provide the movement assembly 1 with a pressing force on the front side of the ear. Among them, the movement assembly 1 can be pressed against the user's skin under the action of the pressing force, so that the acoustic output device 100 does not block the external auditory canal of the ear when it is in a worn state.

[0038] In some other embodiments, the acoustic output device 100 may not include the ear-hanging component 2 and the rear-hanging component 3, but include other fixed structures (not shown), and the core component 1 is fixed on the fixed structure, so that the core component 1 is fitted to the ear, head or other parts of the user through the fixed structure, and then the air-conducted sound waves and / or bone-conducted sound waves output by the core component 1 are transmitted to the user. For example, the fixed structure can be a head-mounted structure, and the head-mounted structure connects the left and right core components 1 to form a head-mounted acoustic output device. For another example, the fixed structure is a bracket for glasses, and the core component is fixed on the glasses bracket. For another example, the fixed structure is an ear clip structure, and the bone-conducted sound waves are transmitted by clamping the core component on the front or back of the auricle. For another example, the fixed structure can also be a helmet, a mask or other structure, which is not specifically limited here.

[0039] For ease of understanding, an exemplary structural schematic diagram of the core assembly 1 and the like of the acoustic output device 100 will be described below in conjunction with the accompanying drawings.

[0040] Figure 2It is a schematic diagram of the structure of the connection part between the movement component and the ear hook component shown in some embodiments of this specification. Figure 3 yes Figure 2 Schematic diagram of the structure explosion of the central movement assembly. Figure 2 and Figure 3 As shown, the movement assembly 1 includes a housing 10 , a bone conduction vibrator 11 and an air conduction vibrator 12 .

[0041] In some embodiments, the housing 10 is provided with a mutually isolated accommodation cavity 1001 and an accommodation cavity 1002. The bone conduction vibrator 11 is provided in the accommodation cavity 1001; the air conduction vibrator 12 is provided in the accommodation cavity 1002. The acoustic output device 100 works together through the bone conduction vibrator 11 and the air conduction vibrator 12. The air conduction vibrator 12 is used to generate air conduction sound waves, and transmits the air conduction sound waves to the housing 10 through the sound conduction holes (e.g., Figure 3 The first sound guide hole 1080 shown in the figure transmits air-conducted sound waves to the user's ear (or ear canal), so that the user receives air-conducted sound; the bone conduction vibrator 11 is used to generate bone-conducted sound waves, and transmits them to the user's cochlea through the shell 10 to generate bone-conducted sound. In some embodiments, the accommodating chamber 1001 is set as a completely enclosed accommodating chamber, and the accommodating chamber 1002 is set as a accommodating chamber with high sealing performance under the condition of ensuring the sound generation of the air conduction vibrator 12. In the above manner, the bone conduction vibrator 11 and the air conduction vibrator 12 are independently set, which can effectively improve the sealing effect of the bone conduction vibrator 11, thereby preventing the bone conduction vibrator 11 from being eroded and damaged by external environmental factors, while ensuring the sound quality effect of the air conduction vibrator 12. In addition, when the bone conduction vibrator 11 and the air conduction vibrator 12 of the acoustic output device 100 work simultaneously, the bone conduction vibrator 11 and the air conduction vibrator 12 are respectively arranged in the accommodating cavity 1001 and the accommodating cavity 1002, which can effectively prevent mutual interference between the bone conduction vibrator 11 and the air conduction vibrator 12 (for example, mutual interference between the vibrations generated by the bone conduction vibrator 11 and the air conduction vibrator 12), thereby effectively improving the sound quality of the acoustic output device 100.

[0042] Continue to see Figure 2 and Figure 3The housing 10 includes a first housing 101, a second housing 102 and a third housing 103. The housing 10 can be composed of the first housing 101, the second housing 102 and the third housing 103, wherein the first housing 101 and the second housing 102 cooperate to form a receiving cavity 1001, the first housing 101 can be provided with a part of the receiving cavity 1002, and the third housing 103 cooperates with the first housing 101 to form another part of the receiving cavity 1002. The housing 10 is composed of the first housing 101, the second housing 102 and the third housing 103 of the above structure, which can make the structure of the movement assembly 1 compact and facilitate the assembly of the movement assembly 1, so as to improve the assembly efficiency of the movement assembly 1. In some embodiments, a portion of the accommodating cavity 1002 may also be disposed in the second housing 102, and the third housing 103 and the second housing 102 cooperate to form another portion of the accommodating cavity 1002, or a portion of the accommodating cavity 1002 may be formed by the cooperation of the first housing 101 and the second housing 102, and the third housing 103 and the first housing 101 and the second housing 102 cooperate to form another portion of the accommodating cavity 1002. The housing 10 implemented in any of the above-mentioned ways can make the structure of the movement assembly 1 compact, and is also conducive to the assembly of the movement assembly 1, so as to improve the assembly efficiency of the movement assembly 1.

[0043] In some embodiments, a partition wall 1012 is provided in the housing 10 for isolating the accommodating cavity 1001 and the accommodating cavity 1002. The partition wall 1012 may be provided on the first housing 101 and / or the second housing 102. Providing the partition wall 1012 on the first housing 101 and / or the second housing 102 may be understood as the partition wall 1012 being a part of the first housing 101 and / or the second housing 102. Of course, the provision of the partition wall 1012 is not limited to being provided on the first housing 101 and / or the second housing 102. In other embodiments, the partition wall 1012 may also be a component that is independent of the first housing 101 and / or the second housing 102. In some embodiments, a partition wall 1012 is disposed on the first shell 101, and the first shell 101 is provided with a sub-accommodating chamber 1010 and a sub-accommodating chamber 1011 located on opposite sides of the partition wall 1012, the opening direction of the sub-accommodating chamber 1010 is arranged along the wall surface of the partition wall 1012, and the opening direction of the sub-accommodating chamber 1011 is arranged crosswise with the wall surface of the partition wall 1012, the second shell 102 is provided with a sub-accommodating chamber 1020, the second shell 102 is covered on the opening end of the sub-accommodating chamber 1010, and the sub-accommodating chamber 1020 cooperates with the sub-accommodating chamber 1010 to form the accommodating chamber 1001; the third shell 103 is provided with a sub-accommodating chamber 1030, the third shell 103 is covered on the opening end of the sub-accommodating chamber 1011, and the sub-accommodating chamber 1030 cooperates with the sub-accommodating chamber 1011 to form the accommodating chamber 1002.

[0044] Figure 4 is a block diagram of an exemplary acoustic output device according to some embodiments of the present specification. Figure 4 As shown, the acoustic output device 200 may include a signal processing module 210 and an output module 220. The signal processing module 210 is configured to process an original audio signal. The original audio signal refers to an electrical signal containing sound information. In some embodiments, the original audio signal may include an audio signal stored inside the acoustic output device 200 or in a device connected to the outside world for communication, etc. For example, the original audio signal may be an electrical signal obtained from a multimedia platform, a terminal device, a storage device, etc.

[0045] The signal processing module 210 can process the original audio signal (i.e., electrical signal) and transmit the processed signal to the output module 220. For example, the signal processing module 210 can process the original audio signal by performing various signal processing operations (e.g., sampling, digitization, amplification, compression, frequency allocation, frequency modulation, filtering, encoding, etc.). The signal processing module 210 can further generate a first audio signal and a second audio signal according to the processed original audio signal, and transmit them to the output module 220. As described herein, the first audio signal refers to an electrical signal related to bone conduction sound waves and / or an electrical signal that affects the generation and output of bone conduction sound waves. The second audio signal refers to an electrical signal related to air conduction sound waves and / or an electrical signal that affects the generation and output of air conduction sound waves. In some embodiments, the first audio signal and the second audio signal are both electrical signals that are finally input to the coil in the bone and air conduction vibrator after processing (e.g., amplification, equalization, filtering, etc.).

[0046] The output module 220 may generate and output bone conduction sound waves (also referred to as bone conduction sound) and / or air conduction sound waves (also referred to as air conduction sound). The output module 220 may receive an audio signal (e.g., the processed first audio signal and the second audio signal) from the signal processing module 210, and generate bone conduction sound waves and / or air conduction sound waves based on the audio signal. As described herein, bone conduction sound waves refer to sound waves conducted in the form of mechanical vibrations through a solid medium (e.g., bone, tissue, etc.). Air conduction sound waves refer to sound waves conducted through the air.

[0047] Specifically, the output module 220 may include a bone conduction vibrator (also referred to as a bone conduction speaker) 221 and an air conduction vibrator 222 (also referred to as an air conduction speaker). The bone conduction vibrator 221 and the air conduction vibrator 222 may be electrically coupled to the signal processing module 210. The bone conduction vibrator 221 may generate bone conduction sound waves within a specific frequency range (e.g., a low frequency range, a medium frequency range, a high frequency range, a medium-low frequency range, and a medium-high frequency range) according to the first audio signal generated by the signal processing module 210. The air conduction vibrator 222 may generate air conduction sound waves of the same or different frequency range as the bone conduction sound waves according to the second audio signal generated by the signal processing module 210. In some embodiments, the bone conduction vibrator 221 and the air conduction vibrator 222 may be two independent functional devices, or two independent components of a single device. As described herein, the air conduction vibrator is independent of the bone conduction vibrator because each of the two speakers is independently driven by an electrical signal to generate sound waves.

[0048] Different frequency ranges can be determined according to actual needs. For example, the low frequency range (also referred to as low frequency) can refer to a frequency range from 20Hz to 150Hz, the medium frequency range (also referred to as medium frequency) can refer to a frequency range from 150Hz to 5kHz, the high frequency range (also referred to as high frequency) can refer to a frequency range from 5kHz to 20kHz, the medium-low frequency range (also referred to as medium-low frequency) can refer to a frequency range from 150Hz to 500Hz, and the medium-high frequency range (also referred to as medium-high frequency) can refer to a frequency range from 500Hz to 5kHz. For another example, the low frequency range can refer to a frequency range from 20Hz to 200Hz, the medium frequency range can refer to a frequency range from 200Hz to 3kHz, the high frequency range can refer to a frequency range from 3kHz to 20kHz, the medium-low frequency range can refer to a frequency range from 100Hz to 1000Hz, and the medium-high frequency range can refer to a frequency range from 1000Hz to 10kHz. It should be noted that the values ​​of the frequency ranges are for illustration purposes only and are not intended to be limiting. The definitions of the above frequency ranges may vary according to different application scenarios and different classification standards. For example, in some other application scenarios, the low frequency range may refer to a frequency range from 20 Hz to 80 Hz, the medium frequency range may refer to a frequency range from 160 Hz to 1280 Hz, the high frequency range may refer to a frequency range from 2560 Hz to 20 kHz, the medium-low frequency range may refer to a frequency range of 80 Hz-160 Hz, and the medium-high frequency range may refer to a frequency range of 1280 Hz-2560 Hz. Optionally, different frequency ranges may have or may not have overlapping frequencies.

[0049] Figure 5 is a block diagram of another exemplary acoustic output device according to some embodiments of the present specification. Figure 5 The acoustic output device 300 shown can be used with Figure 4The present invention is similar to the acoustic output device 200 shown in the figure, except that the signal processing module 310 further includes a bone conduction signal processing circuit 311 and an air conduction signal processing circuit 312. The bone conduction signal processing circuit 311 can be configured to process and generate a first audio signal. The air conduction signal processing circuit 312 can be configured to process and generate a second audio signal.

[0050] In some embodiments, the bone conduction signal processing circuit 311 and the air conduction signal processing circuit 312 may respectively include an amplifier, an equalizer, a filter, etc. In some embodiments, the bone conduction signal processing circuit 311 and the air conduction signal processing circuit 312 may also share an amplifier, an equalizer, a filter, etc.

[0051] The output module 320 includes a bone conduction vibrator 321 and an air conduction vibrator 322. The bone conduction vibrator 321 and the air conduction vibrator 322 can be respectively Figure 4 The bone conduction vibrator 221 and the air conduction vibrator 222 of the output module 220 are the same or similar, and are not repeated here. The bone conduction vibrator 321 can be electrically coupled to the bone conduction signal processing circuit 311. The bone conduction vibrator 321 can generate and output bone conduction sound waves within a specific frequency range according to the first audio signal generated by the bone conduction signal processing circuit 311. The air conduction vibrator 322 can be electrically coupled to the air conduction signal processing circuit 312. The air conduction vibrator 322 can generate and output air conduction sound waves within the same or different frequency range as the bone conduction sound waves according to the second audio signal generated by the air conduction signal processing circuit 312.

[0052] In some embodiments, the bone conduction signal processing circuit 311 can be integrated with the bone conduction vibrator 321 or arranged in the same cavity (e.g., the accommodating cavity 1001). Similarly, the air conduction signal processing circuit 312 can be integrated with the air conduction vibrator 322 or arranged in the same cavity (e.g., the accommodating cavity 1002). In some embodiments, the bone conduction signal processing circuit 311 can be arranged in different cavities from the bone conduction vibrator 321. For example, the bone conduction signal processing circuit 311 can be arranged in the ear hook component 2, and the bone conduction vibrator 321 is arranged in the accommodating cavity 1001. Similarly, the air conduction signal processing circuit 312 can be arranged in different cavities from the air conduction vibrator 322. For example, the air conduction signal processing circuit 312 can be arranged in the ear hook component 2, and the air conduction vibrator 322 is arranged in the accommodating cavity 1002.

[0053] In some embodiments, the first audio signal and the second audio signal have a crossover point. In this specification, the crossover point refers to the intersection of the first audio signal and the second audio signal in the frequency domain that are processed by the signal processing module (e.g., signal processing modules 210, 310) and output to the bone conduction vibrator and the air conduction vibrator. Among them, the first audio signal includes a first frequency band (e.g., medium and high frequency), and the first frequency band includes frequency components with frequencies above the crossover point; the second audio signal includes a second frequency band (e.g., medium and low frequency), and the second frequency band includes frequency components with frequencies below the crossover point.

[0054] It should be noted that, in this manual, the crossover point can be measured in the following way: connect a lead in parallel with the input of the bone conduction vibrator and the air conduction vibrator from the output of the signal processing module, and use a sound card and Audition software to record the two sets of electrical signals and convert them to the frequency domain. The intersection of the curves corresponding to the two sets of electrical signals in the frequency domain is the crossover point.

[0055] In some embodiments, based on the frequency division point, the signal processing module 310 can determine the components of the original audio signal whose frequencies are within the first frequency band (i.e., the first audio signal) and the components whose frequencies are within the second frequency band (i.e., the second audio signal). The bone conduction vibrator 321 vibrates in response to the first audio signal to generate bone conduction sound waves within the first frequency band, and the air conduction vibrator 322 vibrates in response to the second audio signal to generate air conduction sound waves within the second frequency band.

[0056] It should be noted that, since the air load pushed by the air conduction vibrator is small, the sound in the second frequency band (for example, medium and low frequencies) is output in the form of air conduction sound waves, which is beneficial to reducing the power consumption of the acoustic output device 100, and the sound leakage of the acoustic output device 100 when the frequency is in the second frequency band is not easily received by the human ear, which has little impact on the user's listening and listening privacy; while the sound in the first frequency band (for example, medium and high frequencies) is output in the form of bone conduction sound waves, and the sound is transmitted to the user's cochlea through the user's bones, tissues, etc., and very little sound leakage occurs. On this basis, even if the acoustic output of the acoustic output device 100 is improved, no large sound leakage will occur; in addition, the sound output of medium and high frequencies provided by the bone conduction vibrator can reduce the vibration caused by the vibration of the bone conduction vibrator, thereby further improving the user experience.

[0057] Combination Figure 4 and Figure 5In order to adjust the output characteristics of the bone conduction vibrator and / or the air conduction vibrator (for example, the frequency, phase, amplitude, etc. of the output bone conduction sound waves and air conduction sound waves), the original audio signal can be processed in the signal processing module 210 or 310 to obtain the first audio signal and / or the second audio signal, so that the bone conduction vibrator and / or the air conduction vibrator can have different output characteristics. For example, the first audio signal and / or the second audio signal may include a signal in a specific frequency range. In some alternative embodiments, the structure in at least one component in the output module 220 or 320 can be modified or optimized so that the output characteristics of the bone conduction vibrator and / or the air conduction vibrator (for example, the frequency range of the output sound waves) can be adjusted.

[0058] In some embodiments, the signal processing module 210 or 310 can process the original audio signal through hardware, software (algorithm) or a combination thereof. For example, the signal processing module 210 may include an amplifier 211. The signal processing module 210 may amplify a certain signal (for example, the original audio signal) through the amplifier 211 (or an amplifying circuit) and / or an amplifying algorithm. For another example, the signal processing module 210 may include an equalizer 212. The equalizer 212 is used to perform equalization processing on the signal (for example, the original audio signal after filtering). For another example, the signal processing module 210 may include a filter 213. The filter 213 is used to filter the original audio signal to obtain the first audio signal and the second audio signal respectively. In some embodiments, the hardware may also include but is not limited to a dynamic range controller (DRC), a phase processor (GAIN), etc.

[0059] In some embodiments, the signal processing module 210 or 310 can process the original audio signal through one or more filters or filter groups to obtain the first audio signal and / or the second audio signal. Exemplary filters or filter groups may include but are not limited to analog filters, digital filters, passive filters, active filters, etc. or combinations thereof. For example, the signal processing module includes a high-pass filter and a low-pass filter. The signal processing module can perform high-pass filtering on the original audio signal to obtain the first audio signal, and perform low-pass filtering on the original audio signal to obtain the second audio signal.

[0060] In some embodiments, the cutoff frequency of the low-pass filter may be the same as the cutoff frequency of the high-pass filter. After the original audio signal is processed by the low-pass filter, the portion higher than the cutoff frequency (i.e., the crossover point) will be filtered out, thereby mainly retaining the low-frequency components below the cutoff frequency (i.e., the second audio signal); similarly, after the original audio signal is processed by the high-pass filter, the portion lower than the cutoff frequency (i.e., the crossover point) will be filtered out, thereby mainly retaining the high-frequency components above the cutoff frequency (i.e., the first audio signal). In some embodiments, the cutoff frequency of the low-pass filter may be different from the cutoff frequency of the high-pass filter. In this case, the crossover point is the intersection of the first audio signal output to the bone conduction vibrator and the second audio signal in the frequency domain.

[0061] It should be noted that, in actual applications, the first audio signal and the second audio signal processed by the signal processing module 210 or 310 may have a certain frequency overlap near the crossover point, and the frequency range of the bone conduction sound wave generated by the bone conduction vibrator in response to the first audio signal corresponds to the frequency range of the first audio signal, and the frequency range of the air conduction sound wave generated by the air conduction vibrator in response to the second audio signal corresponds to the frequency range of the second audio signal. Therefore, the bone and air conduction sound waves generated by the bone and air conduction vibrators may overlap within a certain frequency band, that is, in the overlapping frequency band, there are both air conduction sound waves and bone conduction sound waves.

[0062] Bone-conducted sound waves and air-conducted sound waves satisfy the acoustic characteristics of in-phase addition and anti-phase cancellation at the cochlea, that is, sounds with the same or substantially the same phase produce a superposition effect at the cochlea, which can improve the user's listening effect; conversely, sounds with opposite or substantially opposite phases produce a cancellation effect at the cochlea, which can reduce the user's listening effect. Therefore, in an embodiment of the present specification, in order to avoid the bone-conducted sound waves and air-conducted sound waves from producing a cancellation effect in the overlapping frequency band, thereby reducing the user's listening effect, the first audio signal and the second audio signal can be controlled to have the same or substantially the same phase in the frequency overlapping part, so that the generated bone-conducted sound waves and air-conducted sound waves at the user's cochlea are superimposed and enhanced, so that the acoustic output device can output a stronger sound in the frequency band sensitive to the human ear (for example, 20Hz-4000Hz), thereby improving the user's listening effect.

[0063] Figure 6 It is a schematic diagram of the frequency response curves of the bone conduction vibrator and the air conduction vibrator and their corresponding phase curves according to some embodiments of this specification.

[0064] See also Figure 6 , curve 61 is the frequency response curve of the air conduction vibrator, curve 63 is the phase curve of the air conduction sound wave; curve 62 is the frequency response curve of the bone conduction vibrator, and curve 64 is the phase curve of the bone conduction sound wave. Figure 6As shown, the bone conduction vibrator has a first resonance peak 621 at a first resonance frequency (e.g., 250 Hz), and its first high-frequency mode appears after 7000 Hz. For example, the first high-frequency mode of the bone conduction vibrator can be specifically manifested as a frequency response curve having a peak and a valley at about 9000 Hz, followed by a resonance peak at about 11 kHz, as shown in FIG. Figure 6 As shown. The air conduction vibrator has a second resonance peak 611 at a second resonance frequency (e.g., 300 Hz) (the resonance peak can be considered as the first resonance peak generated by the air conduction vibrator), and has a third resonance peak 612 at a third resonance frequency (e.g., 4200 Hz) (i.e., the first high-frequency resonance peak of the air conduction vibrator). In some embodiments, the first resonance peak 621 can be the first resonance peak generated by the bone conduction vibrator in the frequency domain, i.e., the resonance peak with the minimum resonance frequency; the second resonance peak 611 can be the first resonance peak generated by the air conduction vibrator in the frequency domain, i.e., the resonance peak with the minimum resonance frequency.

[0065] Combining the frequency response curve 62 and phase curve 64 of the bone conduction vibrator, it can be seen that the phase of the bone conduction signal is relatively stable between its first resonance peak 621 and the frequency band corresponding to before its first high-frequency mode appears; combining the frequency response curve 61 and phase curve 63 of the air conduction vibrator, it can be seen that the phase of the corresponding air-conducted sound wave between its second resonance peak 611 and the third resonance peak 612 (the first high-frequency resonance peak of the air conduction vibrator) is relatively stable.

[0066] In some embodiments, in order to make the bone-conducted sound waves and air-conducted sound waves generated by the acoustic output device in the overlapping frequency band of the bone-conducted sound waves and the air-conducted sound waves superimposed and enhanced on the user's cochlea, it is necessary to make the phases of the bone-conducted sound waves and the air-conducted sound waves in the overlapping frequency band the same or substantially the same. At this time, the crossover point of the first audio signal and the second audio signal can be located in the frequency band where the phases of the bone-conducted vibrator and the air-conducted vibrator are relatively stable, so that the first audio signal and the second audio signal can be stably maintained the same or substantially the same in the frequency band where the phases are relatively stable through hardware, software or a combination thereof, so that the effects of the bone-conducted sound waves and the air-conducted sound waves on the user's cochlea are in phase and enhanced, thereby improving the user's listening effect.

[0067] In some embodiments, in order to ensure that the acoustic output effect of the acoustic output device in a lower frequency band (for example, 300Hz-1000Hz) is better, it is necessary to make the phase of the bone and air-conducted sound waves more stable when the crossover point is in the lower frequency band. Since the phase of the bone and / or air-conducted sound waves fluctuates greatly before the frequency corresponding to their respective first resonance peaks (that is, the first resonance frequency and / or the second resonance frequency), the crossover point can be greater than the first resonance frequency and the second resonance frequency, that is, the crossover point can be greater than the larger of the first resonance frequency and the second resonance frequency. In some embodiments, in order to ensure that the acoustic output effect of the acoustic output device in a higher frequency band (for example, 2500Hz-5000Hz) is better, it is necessary to make the phase of the bone and air-conducted sound waves more stable when the crossover point is in the higher frequency band. However, since the first high-frequency resonant frequency of the bone conduction vibrator is greater than the first high-frequency resonant frequency of the air conduction vibrator, and the phase fluctuation of the air-conducted sound wave is large after the frequency corresponding to the first high-frequency resonant peak of the air conduction vibrator (i.e., the third resonant frequency), the crossover point can be smaller than the first high-frequency resonant frequency of the bone conduction vibrator and the first high-frequency resonant frequency of the air conduction vibrator (i.e., the third resonant frequency), that is, the crossover point can be smaller than the smaller of the first high-frequency resonant frequency of the bone conduction vibrator and the first high-frequency resonant frequency of the air conduction vibrator (i.e., the third resonant frequency).

[0068] In some embodiments, in order to ensure that the acoustic output effect of the acoustic output device is better within the frequency band that the human ear is sensitive to (for example, 300Hz-3500Hz), it is necessary to make the phase of the bone and air conduction sound waves relatively stable when the crossover point is within the frequency band that the human ear is sensitive to. Since the phase of the bone conduction sound wave is stable between the first resonant frequency and its first high-frequency resonant frequency, and the phase of the air conduction sound wave is stable between the second resonant frequency and the third resonant frequency, and the first high-frequency resonant frequency of the bone conduction vibrator is greater than the third resonant frequency of the air conduction vibrator, the crossover point is located within the frequency range between the second resonant frequency or the first resonant frequency and the third resonant frequency. For ease of understanding, combined with Figure 7 To explain, at this time, when the first resonant frequency F1 is higher than the second resonant frequency F2 (or the second resonant frequency F2 is higher than the first resonant frequency F1), since the first high-frequency resonant frequency of the bone conduction vibrator is higher than the first high-frequency resonant frequency of the air conduction vibrator (i.e., the third resonant frequency F3), the crossover point F4 is greater than the first resonant frequency F1 (or the second resonant frequency F2), and the crossover point F4 is less than the first high-frequency resonant frequency of the air conduction vibrator (i.e., the third resonant frequency F3). Therefore, in order to ensure that the acoustic output effect of the acoustic output device is better in the frequency band that the human ear is sensitive to (for example, 300Hz-3500Hz), the crossover point F4 is located in the frequency range between the first resonant frequency F1 (or the second resonant frequency F2) and the third resonant frequency F3. Among them, the description of the third resonant frequency can be found in Fig.11 and its description.

[0069] In some embodiments of the present specification, the crossover point is set within a relatively stable range of phases in the phase curves of the bone and air conduction oscillators to ensure that the phases of the bone and air conduction sound waves near the crossover point tend to be stable, which makes it easier to ensure that the phases of the bone conduction sound waves and the air conduction sound waves are the same, and ensure that the sound signal near the crossover point does not suddenly drop relative to its front and rear frequency bands (for example, its frequency response curve is "concave" near the crossover point), thereby achieving "superposition" of the bone and air conduction sound waves near the crossover point and producing an effect of in-phase enhancement.

[0070] In some embodiments, since the acoustic output device uses an air conduction vibrator to provide mid-low frequency output and a bone conduction vibrator to provide mid-high frequency output, continue to refer to Figure 6 and Figure 7 , in order to ensure the output effect of the acoustic output device at low frequency, the lower the second resonant frequency F2, the better. At the same time, in order to improve the bone conduction sound of the bone conduction vibrator in the medium and high frequency range, the first resonant frequency F1 should not be too small. At this time, the second resonant frequency F2 can be made smaller than the first resonant frequency F1, so that the air conduction sound output by the air conduction vibrator in the low frequency range has a larger sound pressure amplitude, and the bone conduction sound output by the bone conduction vibrator in the medium and high frequency range has a larger sound pressure amplitude. For example, the first resonant frequency F1 is in the range of 300Hz-500Hz, and the second resonant frequency F2 is in the range of 100Hz-300Hz. For another example, the first resonant frequency F1 is in the range of 300Hz-400Hz, and the second resonant frequency F2 is in the range of 150Hz-250Hz.

[0071] In some embodiments of the present specification, by making the second resonant frequency smaller than the first resonant frequency, it can be ensured that the air conduction vibrator can have a relatively large output within a lower frequency range, thereby ensuring that the low-frequency output of the air conduction vibrator can cover a wider low-frequency range, so that the acoustic output device can guarantee a higher acoustic output within a wider frequency range, so as to ensure that the acoustic output device has a better acoustic effect within the audible threshold (for example, 20Hz-5000Hz).

[0072] In some embodiments, in certain scenarios where vibration output is required, such as simulated gunshots in games, car vibrations, vibration feedback of prompt sounds, etc., in order to make the acoustic output device 100 output sound while being closer to the scene application, so that the user has a better experience, the second resonant frequency F2 can be made greater than the first resonant frequency F1. In some embodiments, by setting the second resonant frequency F2 to be greater than the first resonant frequency F1, the intermediate frequency sensitivity of the air conduction vibrator can be improved, the power consumption of the whole machine at high volume can be reduced, and the battery life of the acoustic output device 100 can be improved; in addition, the reliability against mechanical shocks such as falling can also be improved.

[0073] Figure 8 It is a cross-sectional schematic diagram of the movement assembly in the BB section direction according to some embodiments of the present specification.

[0074] In some embodiments, in combination Figure 3 and Figure 8 , the bone conduction vibrator 11 includes a vibrating plate 111. Driven by the first audio signal, the vibrating plate 111 generates mechanical vibrations along the first vibration direction X1 (i.e., the direction perpendicular to the paper surface). The vibration of the vibrating plate 111 transmits bone-conducted sound waves to the user through the contact between the shell 10 and the user's skin. The first resonant frequency F1 of the bone conduction vibrator 11 is related to the vibration system formed by the vibrating plate 111, the shell 10, the magnetic circuit system of the bone conduction vibrator 11 (for example, a magnetic cover, a magnet, a coil, etc.), and the vibration transmission structure between the vibrating plate 111 and the shell 10. The resonant frequency of the vibration system can be regarded as the first resonant frequency F1 of the bone conduction vibrator 11. It should be noted that, in practical applications, since the air conduction vibrator 12 and the bone conduction vibrator 11 are integrated to form the acoustic output device 100, when the bone conduction vibrator 11 vibrates, the air conduction vibrator 12 can serve as a load of the bone conduction vibrator 11, and therefore, the air conduction vibrator 12 (for example, its mass, the vibration direction of the diaphragm, etc.) may affect the first resonant frequency F1 of the bone conduction vibrator 11. At this time, the first resonant frequency F1 of the bone conduction vibrator 11 may be related to the above-mentioned vibration system and the air conduction vibrator 12, and the resonant frequency of the vibration system and the air conduction vibrator 12 can be regarded as the first resonant frequency F1 of the bone conduction vibrator 11.

[0075] In some embodiments, in combination Figure 3 and Figure 8 , the air conduction vibrator 12 includes a diaphragm 121. The diaphragm 121 divides the accommodating cavity 1002 into a rear cavity 1004 and a front cavity 1003 located on opposite sides of the diaphragm 121. The rear cavity 1004 is located on the side of the diaphragm 121 away from the partition wall 1012, and the front cavity 1003 is located between the diaphragm 121 and the partition wall 1012. The second audio signal drives the diaphragm 121 to generate mechanical vibration along the second vibration direction X2, and generates air-conducted sound waves through the propagation of a medium such as air. The second resonant frequency F2 of the air conduction vibrator 12 is related to the characteristics of the diaphragm 121 itself, and the resonant frequency of the diaphragm 121 can be regarded as the second resonant frequency F2 of the air conduction vibrator 12.

[0076] Under normal circumstances, in the low frequency range, the vibration of the bone conduction vibrator 11 in the frequency range near its first resonant frequency F1 will bring a strong sense of vibration to the user's face. As the frequency of the bone conduction sound wave output by the bone conduction vibrator 11 increases, the sense of vibration brought to the user's face by the bone conduction vibrator 11 gradually weakens. For example, the bone conduction vibrator will produce a strong sense of vibration (such as a slapping feeling) within 150Hz-300Hz, a weaker sense of vibration (such as a tingling feeling) at 300Hz-400Hz, and a relatively slight sense of vibration at 400Hz-600Hz. Therefore, in some embodiments, in order to avoid the output frequency of the bone conduction vibrator 11 being too low, resulting in the bone conduction vibrator 11 producing too strong a sense of vibration, thereby giving the user a poor user experience, the crossover point may be not less than 300Hz. In some embodiments, in order to further weaken the sense of vibration generated by the bone conduction vibrator 11, the crossover point may be not less than 350Hz. In some embodiments, the crossover point may be not less than 400Hz. In some embodiments, the crossover point may be not less than 500Hz.

[0077] In some embodiments of the present specification, by setting the crossover point to be no less than 300 Hz, the bone conduction vibrator is prevented from generating more low-frequency vibrations, thereby avoiding excessive vibration and resulting in a poor user experience, thereby ensuring the low-frequency performance of the acoustic output device.

[0078] Starting from the first resonant frequency F1 or the second resonant frequency F2, the phase of the bone-conducted sound wave or the phase of the air-conducted sound wave tends to be stable as the frequency increases. Figure 6 As shown, for the phase of the bone-conducted sound wave (corresponding to curve 64), within the frequency range of 250Hz-350Hz, the phase of the bone-conducted sound wave gradually decreases; starting from 350Hz, the phase of the bone-conducted sound wave tends to be stable. For the phase of the air-conducted sound wave (corresponding to curve 63), within the frequency range of 200Hz-300Hz, the phase of the air-conducted sound wave gradually decreases; starting from 300Hz, the phase of the air-conducted sound wave tends to be stable. It should be noted that the phase of the bone-conducted sound wave or the air-conducted sound wave tends to be stable, which may refer to the phase fluctuation of the bone-conducted sound wave or the air-conducted sound wave being less than a certain degree, for example, 30 degrees, 20 degrees, 10 degrees, etc.

[0079] In some embodiments, in order to further ensure that the bone-conducted sound waves and the air-conducted sound waves increase in phase in the frequency band near the crossover point, the crossover point can be avoided from the frequency band near the first resonant frequency F1 or the second resonant frequency F2 and the phase is still gradually increasing or gradually decreasing, so that it is located in the frequency band where the phase of the bone and air-conducted sound waves is stable. The crossover point can be located after the first resonant frequency F1 and the second resonant frequency F2 and at a certain distance from the first resonant frequency F1 and the second resonant frequency F2. For example, the difference between the first resonant frequency F1 and the second resonant frequency F2 and the crossover point is not less than 100Hz. In other words, the difference between the larger of the first resonant frequency F1 and the second resonant frequency F2 and the crossover point is not less than 100Hz. In some embodiments, in order to make the crossover point located in the frequency band where the phase of the bone-conducted sound waves and the air-conducted sound waves is more stable (for example, the phase difference between the bone and air-conducted sound waves is less than 20 degrees), the difference between the larger of the first resonant frequency F1 and the second resonant frequency F2 and the crossover point can be not less than 200Hz. In some embodiments, in order to make the crossover point located in the frequency band where the phases of bone-conducted sound waves and air-conducted sound waves are particularly stable (for example, the phase difference between bone-conducted sound waves and air-conducted sound waves is less than 10 degrees), the difference between the larger of the first resonant frequency F1 and the second resonant frequency F2 and the crossover point can be no less than 300 Hz.

[0080] In some embodiments of the present specification, by making the difference between the first resonant frequency and the second resonant frequency and the crossover point satisfy a certain threshold range, it is helpful to ensure that the phase of the sound wave in the frequency band near the crossover point is in a stable range. It can further avoid the fluctuation of the resonant frequency of the bone / air conduction vibrators in different batches of devices due to differences in the preparation process, resulting in different bone and air sound wave phases in the frequency band near the crossover point corresponding to different batches of devices, thereby ensuring the output performance of the acoustic output device and improving the output stability of the prepared acoustic output device.

[0081] In some embodiments, since the air load pushed by the air-conducted vibrator is small, the power consumption can be effectively reduced. In order to make the acoustic output of the acoustic output device output more in the form of air-conducted sound waves to reduce the power consumption of the acoustic output device, the crossover point can be set at a higher frequency band, for example, 1000Hz-2000Hz, 1500Hz-2500Hz, etc. However, at this time, the human ear is relatively sensitive to the air-conducted sound near the crossover point and at a frequency lower than the crossover point, resulting in the sound leakage of the acoustic output device being easily perceived by the surrounding people, which may affect the user's listening and listening privacy.

[0082] Therefore, in some embodiments, continue to see Figure 8In order to reduce the sound leakage of the acoustic output device, the shell 10 (for example, the first shell 101, the second shell 102 and / or the third shell 103) of the acoustic output device 100 may be provided with a first sound guide hole 1080 and a second sound guide hole 1081. The first sound guide hole 1080 connects the rear cavity 1004 with the external environment, and the second sound guide hole 1081 connects the front cavity 1003 with the external environment. The first sound guide hole 1080 is used to conduct the air-conducted sound waves generated by the output air-conducting vibrator 12, and the second sound guide hole 1081 is used to relieve the pressure of the air-conducting vibrator 12 to ensure the normal and stable operation of the air-conducting vibrator 12. In some embodiments, the air-conducting vibrator 12 can radiate sounds of equal amplitude and opposite phase to the outside through two sound guide holes (i.e., the first sound guide hole 1080 and the second sound guide hole 1081). At this time, the first sound guide hole 1080 and the second sound guide hole 1081 can form a dipole output structure to reduce the sound leakage of the air conduction vibrator 12 in the far field, thereby improving the user's listening experience and listening privacy.

[0083] Fig. 9 is an exemplary acoustic field diagram of a dipole according to some embodiments of this specification. Fig. 9 The air-conducted sound waves output by the acoustic output device are guided along the first sound guide hole 1080 and the second sound guide hole 1081. The first sound guide hole and the second sound guide hole can be regarded as the first sound source AS1 and the second sound source AS2 with equal amplitude (or substantially equal) and opposite phase (or substantially opposite). The first sound source AS1 and the second sound source AS2 form a dipole 2 or a quasi-dipole. The dipole 2 or the quasi-dipole can be formed as follows Fig. 9 The radiated sound field is similar to the shape of "8". In the straight line direction where the first sound guide hole 1080 and the second sound guide hole 1081 are connected, the sound radiated by the sound guide hole is the largest, and the sound radiated in other directions is significantly smaller. Therefore, the sound radiated by the acoustic output device to the surrounding environment (i.e., far-field sound leakage) can be reduced by providing at least two sound guide holes in the acoustic output device to construct a dipole or a dipole-like structure.

[0084] Therefore, in some embodiments, in order to enable the first sound guide hole 1080 and the second sound guide hole 1081 to form a dipole or a quasi-dipole to improve the sound leakage reduction capability of the acoustic output device, the amplitude difference of the sound radiated from the two sound guide holes can be less than 6dB (for example, the amplitude difference is 1dB, 3dB, 5dB, etc.), and the phase difference of the sound radiated through the two sound guide holes is within the range of 150°-210°. In some embodiments, in order to make the quasi-dipole formed by the first sound guide hole 1080 and the second sound guide hole 1081 more standard to further improve the sound leakage reduction capability of the acoustic output device, the amplitude difference of the sound emitted by the two sound guide holes is less than 5dB, and the phase difference of the sound emitted by the two sound guide holes is 160°-200°. In some embodiments, the amplitude difference of the sound emitted by the two sound guide holes is less than 3dB, and the phase difference of the sound emitted by the two sound guide holes is 170°-190°. In some embodiments, the difference in the amplitude of the sound emitted by the two sound guide holes is less than 3dB, and the phase difference of the sound emitted by the two sound guide holes is 175°-185°. In some embodiments, in order to make the difference in the amplitude of the sound radiated from the two sound guide holes less than 6dB, the difference in the near-field sound pressure level of the two sound guide holes can be made less than 6dB. It can be understood that the smaller the difference in the near-field sound pressure level, the more significant the sound waves with the same amplitude and opposite phase in the far field are to cancel each other out, and the better the effect of reducing sound leakage.

[0085] In this specification, the near-field sound pressure level difference refers to the difference in sound pressure level of the sound radiated to the near-field position by the two sound guide holes. The near-field position of the sound guide hole may refer to a position within 5 mm from the sound guide hole. For ease of understanding, the near-field sound pressure level difference may be expressed as the difference in sound pressure level at the two sound guide holes of the acoustic output device 100.

[0086] In some embodiments, the near-field sound pressure level test method can be to measure the sound pressure of the sound (the first sound and the second sound, respectively) radiated from the first sound guide hole and the second sound guide hole at a specific frequency point (for example, 1000Hz), and then calculate (for example, take the common logarithm of the ratio of the sound pressure to be measured to the reference sound pressure, and then multiply it by 20 to obtain the sound pressure level) to obtain the sound pressure level difference between the first sound and the second sound. In some embodiments, when testing the sound of the first sound guide hole (or the second sound guide hole), a baffle can be used to separate the first sound guide hole and the second sound guide hole to avoid interference with the test by the second sound guide hole (or the first sound guide hole). The sound pressure at the first sound guide hole can be understood as the sound pressure at a position close to the first sound guide hole, and the sound pressure at the second sound guide hole can be understood as the sound pressure at a position close to the second sound guide hole. For example, the sound collection device can be set at 4mm away from the first sound guide hole (or the second sound guide hole) to collect the first sound (or the second sound) as the sound pressure at the first sound guide hole (or the second sound guide hole).

[0087] In some embodiments, when testing the sound of the first sound guide hole and the second sound guide hole, the position 4 cm away from the first sound guide hole and the second sound guide hole (i.e., the collection position) can be respectively in a pair of opposite directions of the acoustic output device 100 (for example, the position 4 cm away from the first sound guide hole is in the direction from the second sound guide hole to the first sound guide hole, and the position 4 cm away from the second sound guide hole is in the direction from the first sound guide hole to the second sound guide hole). The sound collection device is respectively set at the two collection positions to collect the sound pressure level of the acoustic output device 100, and the difference between the two sound pressure levels is calculated, which is the near-field sound pressure level difference between the first sound guide hole and the second sound guide hole.

[0088] By controlling the near-field sound pressures of the sounds radiated from the first sound guide hole and the second sound guide hole to be similar, it can be ensured that the first sound and the second sound effectively interfere with each other in a specific direction of the far field, thereby effectively reducing sound leakage of the acoustic output device 100 in the far field.

[0089] In some embodiments of the present specification, by making the air conduction vibrator output mid-low frequency sound and the bone conduction vibrator output mid-high frequency sound, it is helpful to reduce the vibration sense caused by the acoustic output device. In addition, by setting a higher frequency crossover point, the acoustic output of the acoustic output device is more output in the form of air-conducted sound waves, which is helpful to reduce the power consumption of the acoustic output device. At the same time, by making the difference in the amplitude and phase difference of the sound emitted by the two sound-conducting holes meet certain conditions, the two sound-conducting holes can form a dipole or a quasi-dipole, thereby improving the ability of the acoustic output device to reduce sound leakage at mid-low frequencies.

[0090] In some embodiments, the near-field sound pressure level difference can be adjusted by adjusting the difference in the acoustic loads of the two sound guide holes. The acoustic load refers to the ratio of the sound pressure value P1 after passing through the sound guide hole to the sound pressure value P0 before passing through the sound guide hole, that is, the acoustic load is equal to P1 / P0. It should be noted that for the acoustic load of a certain sound guide hole, the larger the acoustic load (or, the closer it is to 1), the smaller its acoustic resistance.

[0091] In some embodiments, the acoustic load can be based on the sound pressure value when the sound guide hole is covered with a gauze (equivalent to P1) and the sound pressure value when it is not covered with a gauze (equivalent to P0) measured at a specific distance, and the acoustic load of the sound guide hole is determined by calculating the ratio of P1 to P0. Specifically, when testing the sound of the sound guide hole, the sound collection device can be set at a distance of 4-5mm from the sound guide hole, and then the sound pressure value when the sound guide hole is covered with a gauze (equivalent to P1) and the sound pressure value when it is not covered with a gauze (equivalent to P0) are collected respectively, and finally the acoustic load of the sound guide hole is calculated. It should be noted that the test signal of the acoustic load can select a single-frequency signal, in which one or more frequency points can be selected, including but not limited to 100Hz, 200Hz, 300Hz, 500Hz, 1000Hz, 2000Hz, 5000Hz and the resonant frequency of the acoustic output device; the test signal can also select white noise, pink noise, and swept frequency signal. It should be noted that in some embodiments, the measured sound pressure level needs to be converted into a sound pressure value first, and then the acoustic load is calculated. Alternatively, the sound pressure levels measured before and after the sound-conducting hole is covered with the gauze can be subtracted, and the sound load value of the sound-conducting hole can be inversely calculated using a logarithmic formula.

[0092] In some embodiments, the difference in acoustic loads of the two sound guide holes may include 0.1, 0.15, 0.2, etc. In some embodiments, the difference in acoustic loads of the two sound guide holes may be less than 0.15. It can be understood that the smaller the difference in acoustic loads of the two sound guide holes, the closer the acoustic impedances of the two sound guide holes are, and thus the smaller the difference in near-field sound pressure levels of the two sound guide holes, and thus the more significant the effect of reducing far-field sound leakage.

[0093] Furthermore, the difference in the acoustic load of the two sound-conducting holes may be less than 0.1. By further narrowing the difference range of the acoustic load of the two sound-conducting holes, the near-field sound pressure level difference of the two sound-conducting holes may be further reduced, thereby further improving the effect of reducing far-field sound leakage. In order to reduce the power consumption of the acoustic output device 100, the crossover point may be moved toward high frequency. When the crossover point moves toward high frequency, that is, the air-conducted sound waves output by the acoustic output device 100 contain more high-frequency components, at this time, the sound leakage of the acoustic output device 100 in the far field gradually increases. Therefore, when the crossover point moves toward high frequency, the difference in the acoustic load of the two sound-conducting holes may be reduced, thereby further improving the effect of reducing far-field sound leakage to ensure the output performance of the acoustic output device 100.

[0094] In some embodiments, in order to reduce the power consumption of the acoustic output device 100, the crossover point can be set at 300Hz-1kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 in the far field, the difference in the acoustic load of the two sound guide holes can be 0-0.12. In some embodiments, in order to further reduce the power consumption of the acoustic output device 100, the crossover point can be set at 1kHz-2kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 (or the air conduction vibrator 12) in the far field, the difference in the acoustic load of the two sound guide holes can be 0-0.1. In some embodiments, in order to further reduce the power consumption of the acoustic output device 100, the crossover point can be set at 1.5kHz-2.5kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 (or the air conduction vibrator 12) in the far field, the difference in the acoustic load of the two sound guide holes can be 0-0.07. In some embodiments, in order to reduce the power consumption of the acoustic output device 100, the crossover point can be set in the range of 2kHz-3kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 (or the air conduction vibrator 12) in the far field, the difference in the acoustic load of the two sound guide holes can be 0-0.05.

[0095] In some embodiments, the near-field sound pressure level difference can also be adjusted by adjusting the ratio of the surface acoustic loads of the two sound guide holes.

[0096] The surface acoustic load refers to the product of the ratio of the sound pressure value P1 after passing through the sound guide hole to the sound pressure value P0 without passing through the sound guide hole and the area S of the sound guide hole, that is, the surface acoustic load is equal to S×P1 / P0.

[0097] In some embodiments, the ratio of the surface acoustic loads of the two sound guide holes may be 0.5, 1, 2.5, etc. In some embodiments, the ratio of the surface acoustic loads of the two sound guide holes may range from 0.5 to 3.5. By adjusting the surface acoustic load ratio of the two sound guide holes to keep it within a suitable ratio range, the acoustic impedances of the two sound guide holes can be made closer, thereby reducing the near-field sound pressure level difference of the two sound guide holes, so as to improve the effect of reducing far-field sound leakage.

[0098] Furthermore, the ratio range of the surface acoustic loads of the two sound-conducting holes can be 0.8-2. It can be understood that by further reducing the ratio range of the surface acoustic loads of the two sound-conducting holes, the effect of reducing far-field sound leakage can be made more significant. In order to reduce the power consumption of the acoustic output device 100, the crossover point can be moved to high frequency. When the crossover point moves to high frequency, that is, the air-conducted sound waves output by the acoustic output device 100 contain more high-frequency components, at this time, the sound leakage of the acoustic output device 100 in the far field gradually increases. Therefore, when the crossover point moves to high frequency, the ratio of the surface acoustic loads of the two sound-conducting holes can be reduced, thereby further improving the effect of reducing far-field sound leakage to ensure the output performance of the acoustic output device 100.

[0099] In some embodiments, in order to reduce the power consumption of the acoustic output device 100, the crossover point can be set at 300Hz-1kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 in the far field, the ratio of the surface acoustic loads of the two sound guide holes can be in the range of 0.5-3.5. In some embodiments, in order to further reduce the power consumption of the acoustic output device 100, the crossover point can be set at 1kHz-2kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 (or the air conduction vibrator 12) in the far field, the ratio of the surface acoustic loads of the two sound guide holes can be in the range of 0.6-2.7. In some embodiments, in order to further reduce the power consumption of the acoustic output device 100, the crossover point can be set at 1.5kHz-2.5kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 (or the air conduction vibrator 12) in the far field, the ratio of the surface acoustic loads of the two sound guide holes can be in the range of 0.7-2. In some embodiments, in order to reduce the power consumption of the acoustic output device 100, the crossover point can be set in the range of 2kHz-3kHz. At this time, in order to reduce the sound leakage of the acoustic output device 100 (or the air conduction vibrator 12) in the far field, the ratio of the surface acoustic loads of the two sound guide holes can be in the range of 0.9-1.2.

[0100] In some embodiments of the present specification, by adjusting the acoustic load difference range and / or the surface acoustic load ratio of the two sound guide holes, the acoustic impedance of the two sound guide holes is made closer, thereby reducing the near-field sound pressure level difference of the two sound guide holes, so that a dipole or a quasi-dipole can be constructed, thereby improving the effect of reducing far-field leakage sound.

[0101] In some embodiments, in a higher frequency band (e.g., 500Hz-3000Hz), when the acoustic output of the acoustic output device is output as air-conducted sound waves, the sound leakage generated by the air-conducted sound waves will affect the user's listening and listening privacy. Therefore, in some embodiments, in order to further reduce the sound leakage of the acoustic output device, the first sound guide hole 1080 and the second sound guide hole 1081 can be made to radiate sounds with phase difference and / or amplitude difference to the outside world to adjust the sound field radiated by the dipole or quasi-dipole. Specifically, the degree of cancellation of the sound output by the acoustic output device in the far field can be changed by adjusting the amplitude difference and phase difference of the two sounds output by the acoustic output device, and when the phase difference meets certain conditions, the acoustic output device can be kept outputting a high volume in a certain direction (e.g., the direction of the user's ear canal opening R1) while suppressing the sound leakage output by the acoustic output device in the opposite direction. At this time, the sound field radiated by the first sound guide hole 1080 and the second sound guide hole 1081 is as follows: Fig.10 shown.

[0102] Fig.10 is a schematic diagram of an exemplary radiation directional sound field of an acoustic output device according to some embodiments of this specification. Fig.10, when the first sound source AS1 generates a first sound and the second sound source AS2 generates a second sound, and the first sound and the second sound have a specific amplitude difference and / or phase difference, the first sound source AS1 and the second sound source AS2 can form a strong directional radiation sound field. At this time, the directivity can be manifested as the sound radiated from the two sound guide holes having a far-field sound pressure level difference of not less than 3dB in at least one pair of opposite directions (for example, the direction of the ear canal and the opposite direction thereof), thereby making the volume in the direction of the user's ear canal larger, and the sound leakage in the opposite direction of the user's ear canal and in other directions smaller, thereby better balancing the openness of the ear canal and the privacy of listening. For example, from Fig.10 It can be seen that the strongly directional radiation sound field has only one main lobe, the sound field radiation in the main lobe and its vicinity is strong, and the sound field radiation in other directions is weak (the sound field intensity in the opposite direction of the main lobe is also relatively weak). When the user wears the acoustic output device, the main lobe can be directed to the user's ear canal opening R1. At this time, only the radiation directed to the ear canal opening R1 and its vicinity is strong, while other directions are weakly directional directions, thereby further reducing the sound leakage of the acoustic output device 100.

[0103] The far-field sound pressure level difference refers to the difference in the sound pressure amplitude of the sound radiated by the two sound guide holes in the far field. The far field of the sound guide hole can refer to a position 10 cm away from the sound guide hole. For ease of understanding, the far-field sound pressure level difference of the two sound guide holes can be expressed as the difference in the sound pressure amplitude at the same or approximately the same longer distance (or symmetrical position) from the two holes in the direction of the line connecting the two sound guide holes. When measuring the sound pressure amplitude of the sound guide hole, for example, when collecting the sound of the first sound guide hole (or the second sound guide hole), the sound collection device can be set at 30 cm away from the first sound guide hole (or the second sound guide hole) for collection.

[0104] In some embodiments, the far-field sound pressure level difference of the two sound guide holes can be adjusted by setting the amplitude difference and phase difference of the sound emitted by the two sound guide holes. It should be noted that the phase of the sound radiated from the sound guide holes (such as the first sound guide hole 1080 and the second sound guide hole 1081) described in the embodiments of this specification can refer to the phase of the sound radiated from the sound guide hole (or the geometric center of the sound guide hole) at a distance of 100°. 4mm (for example, 4mm in front of the sound guide hole) measured phase. In some embodiments, the method for testing the phase difference can be to measure the phase of the sounds radiated from the two sound guide holes (the first sound and the second sound, respectively), and then calculate the phase difference between the first sound and the second sound. When testing the sound of the first sound guide hole (or the second sound guide hole), a baffle can be used to separate the first sound guide hole and the second sound guide hole to avoid the first sound guide hole (or the second sound guide hole) from interfering with the test. Further, the sound collection device can be placed on the line connecting the first sound guide hole and the second sound guide hole and collect the first sound at 4mm from the first sound guide hole (or the second sound guide hole), further avoiding the first sound guide hole (or the second sound guide hole) from interfering with the test. For example, the size of the baffle can be a standard size. For example, the length, width and height of the baffle can be 1650mm, 1350mm and 30mm, respectively. It should be further explained that when the number of the first sound guide hole (or the second sound guide hole) is two or more, any one of them can be selected for testing. For example, a first sound guide hole and a second sound guide hole located at a specific relative position (e.g., the minimum or maximum relative distance) can be selected to test the phase of the sound emitted by each of them, and calculate the phase difference. In addition, the sound measurement in a specific frequency band (e.g., 0Hz-8000Hz) does not have to be achieved by exhaustive enumeration, but can be achieved by setting multiple (e.g., 20-30) frequency sampling points with equal step sizes and endpoints as the frequency band endpoints, and measuring the sound at each sampling point.

[0105] In some embodiments, the front cavity 1003 or the rear cavity 1004 of the air conduction oscillator 12 may form a third resonance peak having a third resonance frequency. Figure 8 , the first sound guide hole 1080 and the rear cavity 1004 can be approximately regarded as a Helmholtz resonance cavity model. The rear cavity 1004 is the cavity of the Helmholtz resonance cavity model, and the first sound guide hole 1080 is the neck of the Helmholtz resonance cavity model. At this time, the resonant frequency of the Helmholtz resonance cavity model is the resonant frequency of the rear cavity 1004. Similarly, the second sound guide hole 1081 and the front cavity 1003 can be approximately regarded as a Helmholtz resonance cavity model. The front cavity 1003 is the cavity of the Helmholtz resonance cavity model, and the second sound guide hole 1081 is the neck of the Helmholtz resonance cavity model. At this time, the resonant frequency of the Helmholtz resonance cavity model is the resonant frequency of the front cavity 1003. For the convenience of description, the smaller of the resonant frequencies of the front cavity 1003 and the rear cavity 1004 is defined as the third resonant frequency.

[0106] In this specification, the third resonance peak is measured by measuring the first high-frequency resonance peak of the frequency response curve of the air conduction vibrator 12 when the input signal of the bone conduction vibrator 11 is disconnected, and the corresponding resonance frequency is the third resonance frequency. Specifically, when the first sound guide hole 1080 is separated from the second sound guide hole 1081 by the baffle, the third resonance peak of the sound generated by the front cavity 1003 or the rear cavity 1004 is measured.

[0107] Fig.11 It is a schematic diagram of a frequency response curve and a corresponding phase curve of an acoustic signal output from two sound-conducting holes coupled to the front and rear cavities of an air-conducting oscillator according to some embodiments of the present specification.

[0108] See also Fig.11 , curve 71 is the frequency response curve of the first sound guide hole, curve 73 is the phase curve corresponding to the first sound guide hole, curve 72 is the frequency response curve of the second sound guide hole, and curve 74 is the phase curve corresponding to the second sound guide hole. Fig.11 It can be seen that the amplitudes of the frequency response curves of the two sound-conducting holes are basically the same (corresponding to curves 71 and 72), and the amplitude deviation is about ±6dB. The phase difference between the two sound-conducting holes is 180° (or close to 180°). After the third resonance peak 711 corresponding to the third resonant frequency, the vibration modes on the frequency response curve 71 or 72 increase, and correspondingly, the phase jumps frequently, and the two sound-conducting holes cannot stably maintain a phase difference of 180° (or close to 180°), resulting in the effect of the dipole formed by the air-conducting vibrator through the two sound-conducting holes becoming worse, and the sound leakage cannot be effectively reduced. In addition, if the crossover point is located near the third resonant frequency, due to the frequent phase jumps of the air-conducting sound waves, it is also difficult for the sound waves output by the air-conducting vibrator and the bone-conducting vibrator to keep the two in phase. Therefore, in some embodiments, whether from the perspective of reducing the sound leakage from air conduction or maintaining the phase stability of the bone-conducting sound waves and the air-conducting sound waves near the crossover point, the crossover point should be avoided from the frequency band where the air-conducting vibrator has a complex vibration mode, that is, the crossover point is less than the third resonant frequency.

[0109] In some embodiments of the present specification, by making the crossover point smaller than the third resonant frequency, the crossover point can be avoided from the frequency band in which the air conduction vibrator has a complex vibration mode, so as to avoid the effect of the dipole formed by the air conduction vibrator through the two sound conducting holes being deteriorated, and failing to effectively reduce sound leakage, and at the same time avoid the phase of the sound waves output by the air conduction vibrator and the bone conduction vibrator being unstable enough and difficult to keep the two in phase.

[0110] In some embodiments, in order to enable the two sound guide holes to stably maintain a phase difference of 180° (or close to 180°) to ensure the sound leakage reduction effect of the air conduction oscillator, the crossover point may be no higher than 3000Hz. In some embodiments, in order to ensure the sound leakage reduction effect of the air conduction oscillator, the crossover point may be no higher than 2500Hz. In some embodiments, in order to ensure the sound leakage reduction effect of the air conduction oscillator, the crossover point may be no higher than 2000Hz.

[0111] In some embodiments, in combination Figure 6 and Figure 7 , in a frequency band before the third resonant frequency F3, the phase of the air-conducted sound wave gradually increases with the increase of frequency, that is, the phase of the air-conducted sound wave before the third resonant frequency F3 tends to fluctuate from stability. Therefore, in order to more easily ensure that the bone-conducted sound waves and the air-conducted sound waves increase in phase in the frequency band near the crossover point, the crossover point F4 can be kept away from the third resonant frequency F3, so that the crossover point F4 is located in a frequency band where the phases of the bone and air-conducted sound waves are stable. For example, the difference between the third resonant frequency F3 and the crossover point F4 is not less than 500Hz. In some embodiments, in order to make the crossover point F4 located in a frequency band where the phases of the bone-conducted sound waves and the air-conducted sound waves are more stable (for example, the phase difference between the bone and air-conducted sound waves is less than 20 degrees), the difference between the third resonant frequency F3 and the crossover point F4 is not less than 550Hz. In some embodiments, in order to make the crossover point F4 located in a frequency band where the phases of the bone-conducted sound waves and the air-conducted sound waves are particularly stable (for example, the phase difference between the bone-conducted sound waves and the air-conducted sound waves is less than 10 degrees), the difference between the third resonant frequency F3 and the crossover point F4 is not less than 600 Hz. In some embodiments, in order to more easily maintain the phases of the bone-conducted sound waves and the air-conducted sound waves in phase, the difference between the third resonant frequency F3 and the crossover point F4 is not less than 650 Hz.

[0112] The phase of the air-conducted sound wave near the third resonant frequency has a certain stable frequency band. In some embodiments of the present specification, by limiting the difference between the third resonant frequency and the crossover point to be no less than 500 Hz, it is beneficial to ensure that the phase of the sound wave in the frequency band near the crossover point is in a relatively stable range. It can further avoid the fluctuation of the resonant frequency of the bone / air-conducted vibrators in different batches of equipment due to differences in the preparation process, resulting in different phases of bone and air sound waves in the frequency band near the crossover point corresponding to different batches of equipment, thereby ensuring the output performance of the acoustic output device and improving the output stability of the prepared acoustic output device.

[0113] like Figure 6As shown, due to the frequency range before the third resonant frequency F3, the phase of the air-conducted sound wave gradually increases with the increase of frequency, and there is a relatively obvious difference between the phase of the air-conducted sound wave in the phase stable interval and the phase at the third resonant frequency F3. In some embodiments, when the crossover point F4 is located in the frequency band where the phase of the air-conducted sound wave is stable, the difference between the phase of the air-conducted sound wave at the crossover point F4 and the phase of the air-conducted sound wave at the third resonant frequency F3 can be greater than 20°. In some embodiments, in order to make the crossover point F4 located in the frequency band where the phase of the bone and air-conducted sound waves is more stable, the difference between the phase of the air-conducted sound wave at the crossover point F4 and the phase of the air-conducted sound wave at the third resonant frequency F3 can be greater than 30°. In some embodiments, in order to make the crossover point F4 located in the frequency band where the phase of the bone and air-conducted sound waves is more stable, the difference between the phase of the air-conducted sound wave at the crossover point F4 and the phase of the air-conducted sound wave at the third resonant frequency F3 can be greater than 50°.

[0114] In some embodiments, Figure 8 As shown, when the first audio signal and the second audio signal are close in phase, the phase of the bone conduction sound wave output by the bone conduction vibrator 11 is close to the phase of the air conduction sound wave output by the air conduction vibrator 12. At this time, in order to achieve the "superposition" of the bone and air conduction sound waves to produce the effect of in-phase addition, at the crossover point, the difference between the phase of the first audio signal and the phase of the second audio signal may not exceed 30°. In some embodiments, in order to better achieve the "superposition" of the bone and air conduction sound waves, at the crossover point, the difference between the phase of the first audio signal and the phase of the second audio signal may not exceed 20°, or not exceed 10°.

[0115] In some embodiments, Figure 8 As shown, when the phases of the first audio signal and the second audio signal are close, the difference between the phase of the bone conduction sound wave output by the bone conduction vibrator 11 and the phase of the air conduction sound wave output by the air conduction vibrator 12 can be close to 180°. At this time, in order to achieve the "superposition" of the bone and air conduction sound waves to produce the effect of in-phase addition, at the crossover point, the difference between the phase of the first audio signal and the phase of the second audio signal can be in the range of 150°-210°, for example, the difference between the phase of the first audio signal and the phase of the second audio signal can be 210°, 200°, 190°, 180°, 170°, 160°, 150°, etc.

[0116] It is understandable that the frequency magnitudes of the crossover point, the first resonant frequency, and the second resonant frequency involved in multiple embodiments of this specification can be determined to be applied alone or in combination based on the purpose and scenario of the setting without violating the principle. The embodiments that are applied alone or in combination are all within the scope disclosed in this specification. For example, since the phase fluctuation of the bone-conducted sound wave is large before the first resonant frequency, and / or the phase fluctuation of the air-conducted sound wave is large before the second resonant frequency, therefore, in order to make the phase of the bone and air-conducted sound waves more stable when the crossover point is in a lower frequency band (for example, 300Hz-1000Hz), thereby ensuring that the acoustic output effect of the acoustic output device in the lower frequency band is better, the crossover point can be greater than the first resonant frequency and the second resonant frequency, that is, the crossover point can be greater than the larger of the first resonant frequency and the second resonant frequency. For another example, since the first high-frequency resonant frequency of the bone conduction vibrator is greater than the first high-frequency resonant frequency of the air conduction vibrator (i.e., the third resonant frequency), and after the third resonant frequency, the phase fluctuation of the air-conducted sound wave is relatively large, in order to make the phase of the bone and air-conducted sound waves relatively stable when the crossover point is in a higher frequency band (e.g., 2500Hz-5000Hz), thereby ensuring that the acoustic output effect of the acoustic output device in this higher frequency band is better, the crossover point can be less than the third resonant frequency. For another example, since the phase of the bone conduction sound wave is stable between the first resonant frequency and its first high-frequency resonant frequency, the phase of the air conduction sound wave is stable between the second resonant frequency and the third resonant frequency, and the first high-frequency resonant frequency of the bone conduction vibrator is greater than the third resonant frequency of the air conduction vibrator, in order to ensure that the phases of the bone and air conduction sound waves are relatively stable when the crossover point is within the frequency band to which the human ear is sensitive (for example, 300Hz-3500Hz), thereby ensuring that the acoustic output effect of the acoustic output device within the frequency band to which the human ear is sensitive is better, the crossover point can be set within the frequency range between the second resonant frequency or the first resonant frequency and the third resonant frequency.

[0117] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

Claims

1. An acoustic output device, comprising: case; A bone conduction vibrator, used for generating bone conduction sound waves and transmitting them to the cochlea through the shell to generate sound; An air conduction vibrator, used for generating air conduction sound waves, which are transmitted to the ear through the sound conduction holes on the shell; A signal processing module is used to provide a first audio signal and a second audio signal to the bone conduction vibrator and the air conduction vibrator respectively, the first audio signal and the second audio signal have a crossover point, the first audio signal and the second audio signal respectively include components with frequencies above and below the crossover point, wherein: The bone conduction vibrator has a first resonance peak at a first resonance frequency. The air conduction vibrator has a second resonance peak at a second resonance frequency, The crossover frequency point is greater than the first resonant frequency and the second resonant frequency.

2. The acoustic output device according to claim 1, wherein: The first resonant frequency is located between the second resonant frequency and the crossover point.

3. The acoustic output device according to claim 1, wherein: The differences between the first resonant frequency and the second resonant frequency and the frequency division point are no less than 100 Hz.

4. The acoustic output device according to claim 1, wherein: At the crossover point, a phase difference between the first audio signal and the second audio signal does not exceed 30°.

5. The acoustic output device according to claim 1, wherein: The crossover frequency point is not less than 300 Hz.

6. The acoustic output device according to claim 5, wherein: The shell includes two sound guide holes, which are used to guide the air-conducted sound waves. The difference in amplitude of the sound radiated through the two sound guide holes is less than 6 dB, and the phase difference is 150°-210°.

7. The acoustic output device according to claim 1, wherein: The air conduction vibrator has a front cavity or a rear cavity, the front cavity or the rear cavity forms a third resonance peak with a third resonance frequency, and the crossover point is less than the third resonance frequency.

8. The acoustic output device according to claim 7, wherein: The difference between the third resonant frequency and the crossover point is not less than 500 Hz.

9. The acoustic output device according to claim 7, wherein: The crossover frequency point is not higher than 3000 Hz.

10. The acoustic output device according to claim 1, wherein The signal processing module performs high-pass filtering and low-pass filtering on the electrical signal containing sound information to obtain the first audio signal and the second audio signal respectively.

11. An acoustic output device, comprising: case; A bone conduction vibrator, used for generating bone conduction sound waves and transmitting them to the cochlea through the shell to generate sound; An air conduction vibrator, used for generating air conduction sound waves, which are transmitted to the ear through the sound conduction holes on the shell; A signal processing module is used to provide a first audio signal and a second audio signal to the bone conduction vibrator and the air conduction vibrator respectively, the first audio signal and the second audio signal have a crossover point, the first audio signal and the second audio signal respectively include components with frequencies above and below the crossover point, wherein: The air conduction vibrator has a front cavity or a rear cavity, the front cavity or the rear cavity forms a third resonance peak with a third resonance frequency, and the crossover point is less than the third resonance frequency.

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