Acoustic output device

Abstract

Acoustic output device, comprehensive: a case; a bone conduction vibration element configured to generate bone conduction sound waves so that the bone conduction sound waves are transmitted through the housing to the cochlea to produce sound; an air conduction vibration element configured to generate air conduction sound waves so that the air conduction sound waves are transmitted to the ear through a sound conduction opening provided in the housing; and a signal processing module configured to provide a first audio signal to the bone conduction vibration element and a second audio signal to the air conduction vibration element, wherein the first audio signal and the second audio signal have a frequency cut-off point, and the first audio signal and the second audio signal each comprise a corresponding component with frequencies above the frequency cut-off point and a corresponding component with frequencies below the frequency cut-off point, where the bone conduction vibration element exhibits a first resonance peak at a first resonance frequency, wherein the first resonance peak is the resonance peak of the bone conduction vibration element with the lowest resonance frequency in the frequency range, the air conduction vibration element exhibits a second resonance peak at a second resonance frequency, wherein the second resonance peak is the resonance peak of the air conduction vibration element with the lowest resonance frequency in the frequency domain, and the frequency cutoff point is higher than the first resonant frequency and the frequency cutoff point is higher than the second resonant frequency.

Description

Cross-reference

[0001] The present application claims priority over the Chinese application filed on 27 October 2023 with application number 202311427342.7, the entire contents of which are incorporated into the present application by reference. Technical field

[0002] The present description concerns the technical field of acoustics, in particular an acoustic output device. State of the art

[0003] Acoustic output devices with combined bone and air conduction, where an air conduction vibrator is primarily responsible for low frequencies and a bone conduction vibrator primarily for high frequencies, can reduce the perceptible vibrations caused by the bone conduction vibrator's oscillation, thus improving the user experience. In acoustic output devices with combined bone and air conduction, a frequency crossover point for bone conduction and air conduction audio signals (i.e., electrical signals) is set so that the bone conduction vibrator and the air conduction vibrator each generate sound thresholds in different primary operating frequency ranges.In practical applications, bone conduction and air conduction audio signals can exhibit some frequency overlap near the frequency crossover point, causing the bone conduction and air conduction sound waves generated by the bone conduction and air conduction vibrating elements, respectively, to overlap. This can lead to the bone conduction and air conduction sound waves canceling each other out of phase in this overlapping frequency range, thus impairing the acoustic performance of the audio output device.

[0004] Therefore, it is necessary to provide an acoustic output device that can prevent the adverse effect caused by the mutual interaction of bone conduction and air conduction audio signals near the frequency crossover point, in order to improve the acoustic performance of the acoustic output device. Disclosure of the invention

[0005] One embodiment of the present description provides an acoustic output device comprising: a housing; a bone conduction vibration element for generating bone conduction sound waves and transmitting them through the housing to the cochlea to produce sound; an air conduction vibration element for generating air conduction sound waves that are transmitted to the ear through a sound conduction opening provided in the housing; and a signal processing module for transmitting a first audio signal or a second audio signal to the bone conduction vibration element or the air conduction vibration element, respectively.to provide to the air conduction vibration element, wherein the first audio signal and the second audio signal have a frequency cut-off point and each include components with frequencies above and below the frequency cut-off point, wherein the bone conduction vibration element has a first resonance peak at a first resonance frequency and the air conduction vibration element has a second resonance peak at a second resonance frequency, and wherein the frequency cut-off point is higher than the first resonance frequency and the second resonance frequency.

[0006] In some embodiments, the first resonant frequency is provided to lie between the second resonant frequency and the frequency cut-off point.

[0007] In some embodiments, it is provided that the difference between the first resonant frequency and the frequency cut-off point, as well as the difference between the second resonant frequency and the frequency cut-off point, is not less than 100 Hz.

[0008] In some embodiments, it is provided that the difference between the phases of the first audio signal and the second audio signal at the frequency crossover point does not exceed 30°.

[0009] In some embodiments, the frequency cutoff point is specified as not being lower than 300 Hz.

[0010] In some embodiments, the housing is provided with two sound guide openings for the purpose of conveying the air-conducting sound waves, wherein the sounds emitted through the two sound guide openings have an amplitude difference of less than 6 dB and a phase difference of 150° to 210°.

[0011] In some embodiments, the difference between the acoustic loads of the two sound-guiding openings is provided for to be less than 0.15.

[0012] In some embodiments, the ratio between the acoustic surface loads of the two sound-guiding openings is provided to be 0.5 to 3.5.

[0013] In some embodiments, the air conduit vibration element is provided to have a front or rear chamber through which a third resonance peak with a third resonance frequency is formed, wherein the frequency cutoff point is lower than the third resonance frequency.

[0014] In some embodiments, it is provided that the difference between the third resonant frequency and the frequency cut-off point is not less than 500 Hz.

[0015] In some embodiments, the frequency cutoff point is not higher than 3000 Hz.

[0016] In some embodiments, the signal processing module is designed to process electrical signals containing acoustic information by high-pass or low-pass filtering in order to obtain the first audio signal or the second audio signal accordingly.

[0017] One of the embodiments described in this document also provides an acoustic output device comprising: a housing; a bone conduction vibration element for generating bone conduction sound waves and transmitting them through the housing to the cochlea to produce sound; an air conduction vibration element for generating air conduction sound waves that are transmitted to the ear through a sound conduction opening provided in the housing; and a signal processing module for transmitting a first audio signal or a second audio signal to the bone conduction vibration element or the air conduction vibration element, respectively.to provide to the air conduction vibration element, wherein the first audio signal and the second audio signal have a frequency cut-off point and each include components with frequencies above and below the frequency cut-off point, wherein the air conduction vibration element has a front or rear chamber through which a third resonant peak with a third resonant frequency is formed, wherein the frequency cut-off point is lower than the third resonant frequency. Brief description of the characters

[0018] The present description is further illustrated by exemplary embodiments, which are described in detail by the accompanying drawings. Such embodiments are not limiting. In the embodiments, the same reference numerals denote the same structures. These show: Fig. Figure 1 shows a schematic representation of an exemplary acoustic output device according to some embodiments of the present description; Fig. 2 shows a schematic structural representation of a connecting section of a core assembly with an ear hook assembly according to some embodiments of the present description; Fig. Figure 3 shows a schematic structural exploded view of the core assembly according to Fig. 2; Fig. Figure 4 shows a block diagram of the exemplary acoustic output device according to some embodiments of the present description; Fig. Figure 5 shows a block diagram of another exemplary acoustic output device according to some embodiments of the present description; Fig. Figure 6 shows a schematic representation of frequency response curves or phase curves of a bone conduction vibration element and an air conduction vibration element according to some embodiments of the present description; Fig. Figure 7 shows a schematic representation of a frequency cutoff point according to some embodiments of the present description; Fig. Figure 8 shows a schematic sectional view of the core assembly according to some embodiments of the present description in a section direction BB; Fig. Figure 9 shows a schematic representation of an exemplary sound field of a dipole according to some embodiments of the present description; Fig. Figure 10 shows a schematic representation of an exemplary directed radiation sound field of the acoustic output device according to some embodiments of the present description; Fig. Figure 11 shows a schematic representation of frequency response curves or corresponding phase curves of acoustic signals according to some embodiments of the present description, which are emitted through two sound guide openings coupled to a front or rear chamber of the air guide vibration element. Detailed designs

[0019] To further explain the technical solutions of the embodiments described in this document, the drawings required for describing these embodiments are briefly summarized below. Naturally, the following drawings represent only some examples or embodiments of the present description, and a person skilled in the art can apply the present description to other similar scenarios based on these drawings without inventive step. Unless obvious from the context or otherwise indicated, identical reference numerals in the drawings represent identical structures or processes.

[0020] It is understood that the terms "system," "device," "unit," and / or "module," as used herein, are a method for distinguishing between different components, elements, parts, or assemblies at different levels. However, where other words can serve the same purpose, these terms may be substituted.

[0021] As shown in the present description and in the claims, the terms "a" and / or "the" need not necessarily refer to the singular form, but may also include the plural form unless clearly indicated otherwise in the context. Generally speaking, the terms "comprise" and "contain" merely serve to indicate the inclusion of expressly identified steps and elements, and these steps and elements do not constitute an exclusive list. Methods or devices may also contain other steps or elements.

[0022] In the explanation of this description, it should be understood that the terms "first," "second," "third," and "fourth," etc., serve only for descriptive purposes and do not indicate or suggest the relative importance or number of the technical features concerned. Thus, the features defined as "first," "second," "third," and "fourth" may explicitly or implicitly include at least one of these features. In the explanation of this description, the word "several" refers to at least two, such as two, three, etc., unless expressly defined otherwise.

[0023] In this description, the terms "connect" and "fasten" and the like are to be understood in a broad sense unless expressly stated or defined otherwise. For example, the term "connect" may refer to a permanent, detachable, or one-piece connection, which may be a mechanical or electrical connection; which may be a direct connection or an indirect connection via an intermediate medium, or internal communication between two elements, or an interaction between the two elements, unless expressly defined otherwise. A person competent in the field may understand the specific meaning of the above terms in the description according to the specific circumstances.

[0024] Fig. Figure 1 shows a schematic representation of an exemplary acoustic output device according to some embodiments of the present description.

[0025] Some embodiments of the present description provide an acoustic output device 100. As in Fig. As shown in Figure 1, the acoustic output device 100 can comprise a core assembly 1, an ear hook assembly 2, and a headband assembly 3. In some embodiments, there are two core assemblies 1. The two core assemblies 1 each serve to transmit vibrations and / or sound to the left and right ears of a user, respectively, and the two core assemblies 1 can be identical or different. For example, one core assembly 1 may be equipped with a microphone, while the other core assembly 1 does not. Another example is that one core assembly 1 may be provided with a button and a corresponding circuit board, while the other core assembly 1 may not have a button or a corresponding circuit board. The two core assemblies 1 can be identical with respect to their core modules (e.g., loudspeaker modules).The following description provides a detailed illustration using one of the two core assemblies 1 as an example. There can be two ear hook assemblies 2, which can be suspended on the user's left and right ears, respectively, so that the core assemblies 1 rest against the user's face. For example, one ear hook assembly 2 can be equipped with a battery, while the other ear hook assembly 2 can be equipped with a control circuit or similar device. One end of each ear hook assembly 2 is connected to its respective core assembly 1, and the other end is connected to the back-of-the-head support assembly 3. The back-of-the-head support assembly 3 connects the two ear hook assemblies 2. The back-of-the-head support assembly 3 is designed to be placed around the user's neck or the back of their head.It can provide a clamping force to clamp the two core assemblies 1 laterally to the user's face and to suspend the ear hook assemblies 2 more stably on the user's ears.

[0026] It should be noted that in some embodiments, the acoustic output device 100 may not include a back-headband assembly 3, wherein the acoustic output device 100 may comprise a core assembly 1 and an earband assembly 2. One end of the earband assembly 2 may be connected to the core assembly 1, while its other end extends along a connection area between the user's ear and head. In some embodiments, the earband assembly 2 may be configured as an arc-shaped structure to fit the user's ear, so that the earband assembly 2 hangs on the user's ear. For example, the earband assembly 2 may have an arc-shaped structure that conforms to the connection area between the user's head and ear. This allows the earband assembly 2 to hang between the ear and the user's head.In some embodiments, the ear hook assembly 2 can also be designed as a clamping structure that adapts to the user's ear, so that the ear hook assembly 2 can be clamped to the user's ear. For example, the ear hook assembly 2 can comprise a hook part and a connecting part, which are connected sequentially. The connecting part connects the hook part to the core assembly 1, so that the acoustic output device 100, in its unworn state (i.e., in its natural state), is arc-shaped in three-dimensional space. In other words, in three-dimensional space, the hook part, the connecting part, and the core assembly 1 are not coplanar.This means that when the acoustic output device 100 is worn, the hook part can primarily be used to hang between the back of the ear and the user's head, and the core assembly 1 can primarily be used to make contact with the front of the user's ear or with the user's head. This, in turn, allows the core assembly 1 to interact with the hook part to clamp the ear. For example, the connecting part can extend outwards from the head so that it interacts with the hook part to provide a clamping force to the front of the ear for the core assembly 1. Under the influence of this clamping force, the core assembly 1 can rest against the user's skin, so that the acoustic output device 100, when worn, does not obstruct the external auditory canal.

[0027] In some other embodiments, the acoustic output device 100 can comprise other mounting structures (not shown) instead of an ear hook assembly 2 or a headband assembly 3. The core assembly 1 is attached to a mounting structure so that it rests against the ear, head, or other parts of the user, thereby transmitting air conduction and / or bone conduction sound waves emitted by the core assembly 1 to the user. For example, the mounting structure can be a headset structure that connects the left and right core assemblies 1 to form an acoustic headset output device. Alternatively, the mounting structure can be, for example, a spectacle frame to which the core assembly is attached.For example, the mounting structure is currently designed as an ear clip, where the core assembly is clamped to the front or back of the ear to transmit bone conduction sound waves. Furthermore, it is also envisaged that the mounting structure could include a helmet, face shield, and similar structures, which are not specifically defined here.

[0028] For better understanding, the core assembly 1 and other exemplary structures of the acoustic output device 100 are described below in connection with the drawings.

[0029] Fig. Figure 2 shows a schematic structural representation of a connecting section of a core assembly with an ear hook assembly according to some embodiments of the present description. Fig. Figure 3 shows a schematic structural exploded view of the core assembly according to Fig. 2. As in Fig. 2 and Fig. As shown in Figure 3, the individual core assembly 1 comprises a housing 10, a bone conduction vibration element 11 and an air conduction vibration element 12.

[0030] In some embodiments, the housing 10 is provided with a receiving chamber 1001 and a receiving chamber 1002, which are separate from each other. The bone conduction vibration element 11 is arranged in the receiving chamber 1001. The air conduction vibration element 12 is arranged in the receiving chamber 1002. In this case, the bone conduction vibration element 11 and the air conduction vibration element 12 operate together in the acoustic output device 100. The air conduction vibration element 12 serves to generate the air conduction sound waves and transmit them through a sound conduction opening provided on the housing 10 (for example, a first sound conduction opening 1080, as shown in [reference]). Fig. 3) to transmit to the user's ear (or ear canal) so that the user receives air-conducted sound. The bone conduction vibration element 11 serves to generate the bone conduction sound waves and transmit them through the housing 10 to the user's cochlea to generate bone-conducted sound. In some embodiments, the receiving chamber 1001 is designed as a completely sealed receiving chamber, while the receiving chamber 1002 is designed as a receiving chamber with a relatively high degree of tightness, which ensures the conditions for sound generation by the air conduction vibration element 12.By arranging the bone conduction vibration element 11 and the air conduction vibration element 12 separately, the sealing effect of the bone conduction vibration element 11 can be effectively improved, thus protecting it from damage caused by external environmental influences and simultaneously ensuring the sound quality of the air conduction vibration element 12. When the bone conduction vibration element 11 and the air conduction vibration element 12 operate simultaneously in the acoustic output device 100, the separate arrangement of the bone conduction vibration element 11 and the air conduction vibration element 12 in the recording chamber 1001 and recording chamber 1002, respectively, further prevents mutual interference between the bone conduction vibration element 11 and the air conduction vibration element 12 (for example, mutual interference between the vibrations produced by the bone conduction vibration element 11 and the air conduction vibration element 12).The vibrations generated by the air conduction vibration element 12 are effectively reduced, thereby effectively improving the sound quality of the acoustic output device 100.

[0031] With further reference to Fig. 2 and Fig. The housing 10 comprises a first housing 101, a second housing 102, and a third housing 103. The housing 10 can be formed by the interaction of the first housing 101, the second housing 102, and the third housing 103. The first housing 101 and the second housing 102 interact to form the receiving chamber 1001. The first housing 101 can be provided with a portion of the receiving chamber 1002. The third housing 103 interacts with the first housing 101 to form the other portion of the receiving chamber 1002. By forming the housing 10 through the interaction of the first housing 101, the second housing 102 and the third housing 103, which are constructed as described above, a compact structure of the core assembly 1 can be achieved at the same time with simplified assembly of the core assembly 1, thus increasing the assembly efficiency of the core assembly 1.In some embodiments, part of the receiving chamber 1002 can also be arranged in the second housing 102, with the third housing 103 interacting with the second housing 102 to form the other part of the receiving chamber 1002. Alternatively, the first housing 101 and the second housing 102 can interact to form part of the receiving chamber 1002, and the third housing 103 interacts with the first housing 101 and the second housing 102 to jointly form the other part of the receiving chamber 1002. The housing 10 realized by one of the aforementioned embodiments enables a compact structure of the core assembly 1 and simultaneously facilitates the assembly of the core assembly 1, thereby increasing the assembly efficiency of the core assembly 1.

[0032] In some embodiments, the housing 10 is provided with a partition 1012, which serves to separate the receiving chamber 1001 from the receiving chamber 1002. The partition 1012 can be arranged on the first housing 101 and / or the second housing 102. The arrangement of the partition 1012 on the first housing 101 and / or the second housing 102 can mean that the partition 1012 is an integral part of the first housing 101 and / or the second housing 102. Of course, the partition 1012 does not have to be arranged on the first housing 101 and / or the second housing 102. In another embodiment, the partition 1012 can be a separate component that is independent of the first housing 101 and / or the second housing 102.In some embodiments, the partition 1012 is arranged on the first housing 101, the first housing 101 being provided with a partial receiving chamber 1010 and a partial receiving chamber 1011 located on opposite sides of the partition 1012. The opening direction of the partial receiving chamber 1010 runs along the wall surface of the partition 1012. The opening direction of the partial receiving chamber 1011, on the other hand, is oriented in an intersection with the wall surface of the partition 1012. The second housing 102 is provided with a partial receiving chamber 1020. The second housing 102 covers an open end of the partial receiving chamber 1010, the partial receiving chamber 1020 cooperating with the partial receiving chamber 1010 to form the receiving chamber 1001. The third housing 103 is provided with a partial receiving chamber 1030.The third housing 103 covers an open end of the partial recording chamber 1011, with the partial recording chamber 1030 cooperating with the partial recording chamber 1011 to form the recording chamber 1002.

[0033] Fig. Figure 4 shows a block diagram of the exemplary acoustic output device according to some embodiments described in this document. As in Fig. As shown in Figure 4, an acoustic output device 200 can comprise a signal processing module 210 and an output module 220. The signal processing module 210 is configured to process original audio signals. The original audio signals are electrical signals that contain acoustic information. In some embodiments, the original audio signals in the acoustic output device 200 can include audio signals stored in the device or audio signals in a specific device that is in communication with the external environment. For example, the original audio signals can be electrical signals received from the multimedia platform, the terminal device, the storage device, or the like.

[0034] The signal processing module 210 can process the original audio signals (i.e., the electrical signals) and then transmit the processed signals to the output module 220. For example, the signal processing module 210 can process the original audio signals by performing various signal processing operations (such as sampling, digitization, amplification, compression, frequency distribution, frequency modulation, filtering, encoding, or the like). The signal processing module 210 can further generate a first audio signal and a second audio signal based on the processed original audio signals and then transmit these to the output module 220. As described herein, the first audio signal refers to an electrical signal relevant to bone conduction sound waves and / or an electrical signal influencing the generation and output of bone conduction sound waves.The second audio signal refers to an electrical signal relevant to the air conduction sound waves and / or an electrical signal influencing the generation and output of the air conduction sound waves. In some embodiments, the first and second audio signals refer to electrical signals that, after processing (such as amplification, equalization, filtering, etc.), are ultimately fed into the coils of the bone conduction and air conduction vibration elements.

[0035] Output Module 220 can generate and output bone conduction sound waves (also known as bone-conducted sound) and / or air conduction sound waves (also known as air-conducted sound). Output Module 220 can receive audio signals (such as processed first and second audio signals) from Signal Processing Module 210 and generate bone conduction sound waves and / or air conduction sound waves based on these audio signals. As described herein, bone conduction sound waves refer to sound waves that are transmitted through solid media (such as bone, tissue, etc.) in the form of mechanical vibration. Air conduction sound waves refer to sound waves that are transmitted through the air.

[0036] In particular, the output module 220 can include a bone conduction vibrator 221 (also referred to as a bone conduction loudspeaker) and an air conduction vibrator 222 (also referred to as an air conduction loudspeaker). The bone conduction vibrator 221 and the air conduction vibrator 222 can be electrically coupled to the signal processing module 210. The bone conduction vibrator 221 can generate bone conduction sound waves in a specific frequency range (such as a low-frequency range, a mid-frequency range, a high-frequency range, a low- and mid-frequency range, or a mid- and high-frequency range) based on the initial audio signal generated by the signal processing module 210.The air conduction vibration element 222 can generate air conduction sound waves in the same or a different frequency range as the bone conduction sound waves, based on the second audio signal generated by the signal processing module 210. In some embodiments, the bone conduction vibration element 221 and the air conduction vibration element 222 can be configured as two independent functional units or as two independent assemblies of a single device. As described herein, the air conduction vibration element is independent of the bone conduction vibration element because each of the two loudspeakers is driven independently by an electrical signal to generate sound waves.

[0037] It is possible to define different frequency ranges according to actual needs. For example, the low-frequency range (also referred to as low frequencies) can refer to a frequency range from 20 Hz to 150 Hz. The medium-frequency range (also referred to as mid frequencies) can refer to a frequency range from 150 Hz to 5 kHz. The high-frequency range (also referred to as high frequencies) can refer to a frequency range from 5 kHz to 20 kHz. The low / medium frequency range (also referred to as low and mid frequencies) can refer to a frequency range from 150 Hz to 500 Hz. The medium / high frequency range (also referred to as mid and high frequencies) can refer to a frequency range from 500 Hz to 5 kHz. The low-frequency range can also, for example, refer to a frequency range from 20 Hz to 200 Hz.The medium frequency range can refer to a frequency range of 200 Hz to 3 kHz. The high frequency range can refer to a frequency range of 3 kHz to 20 kHz. The low / medium frequency range can refer to a frequency range of 100 Hz to 1000 Hz. The medium / high frequency range can refer to a frequency range of 1000 Hz to 10 kHz. It should be noted that the specified frequency range is for descriptive purposes only and is not a limiting factor. The definitions for the above frequency range can vary depending on different application scenarios and classification criteria. In some other application scenarios, for example, the low frequency range may refer to a frequency range of 20 Hz to 80 Hz. The medium frequency range may refer to a frequency range of 160 Hz to 1280 Hz.The high-frequency range can refer to a frequency range from 2560 Hz to 20 kHz. The low- or medium-frequency range can refer to a frequency range from 80 Hz to 160 Hz. The medium- or high-frequency range can refer to a frequency range from 1280 Hz to 2560 Hz. Optionally, different frequency ranges can have either one or no overlapping frequency.

[0038] Fig. Figure 5 shows a block diagram of another exemplary acoustic output device according to some embodiments described in this document. In some embodiments, a Fig. 5 acoustic output device 300 shown, similar to the one in Fig. The acoustic output device 200 shown in Figure 4 is configured as follows. The difference is that a signal processing module 310 further comprises 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 or generate a first audio signal. The air conduction signal processing circuit 312 can be configured to process or generate a second audio signal.

[0039] In some embodiments, the bone conduction signal processing circuit 311 and the air conduction signal processing circuit 312 may each 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 jointly use an amplifier, an equalizer, a filter, etc.

[0040] An output module 320 comprises a bone conduction vibration element 321 and an air conduction vibration element 322. The bone conduction vibration element 321 and the air conduction vibration element 322 can each be configured in the same or a similar way to the bone conduction vibration element 221 and the air conduction vibration element 222 of the output module 220 according to Fig. 4. This is why it is not described again here. The bone conduction vibration element 321 can be electrically coupled to the bone conduction signal processing circuit 311. The bone conduction vibration element 321 can generate and output bone conduction sound waves in a specific frequency range based on the first audio signal generated by the bone conduction signal processing circuit 311. The air conduction vibration element 322 can be electrically coupled to the air conduction signal processing circuit 312. Based on the second audio signal generated by the air conduction signal processing circuit 312, the air conduction vibration element 322 can generate and output air conduction sound waves in the same or a different frequency range as the bone conduction sound waves.

[0041] In some embodiments, the bone conduction signal processing circuit 311 can be integrated or arranged together with the bone conduction vibration element 321 in the same chamber (e.g., the receiving chamber 1001). Similarly, the air conduction signal processing circuit 312 can be integrated or arranged together with the air conduction vibration element 322 in the same chamber (e.g., the receiving chamber 1002). In some embodiments, the bone conduction signal processing circuit 311 can be arranged in a different chamber than the bone conduction vibration element 321. For example, the bone conduction signal processing circuit 311 can be arranged in the ear hook assembly 2, while the bone conduction vibration element 321 is arranged in the receiving chamber 1001. Similarly, the air conduction signal processing circuit 312 can be arranged in a different chamber than the air conduction vibration element 322.For example, the air conduction signal processing circuit 312 can be arranged in the ear hook assembly 2, while the air conduction vibration element 322 is arranged in the receiving chamber 1002.

[0042] In some embodiments, the first and second audio signals have a frequency cutoff point. In this description, the frequency cutoff point refers to an intersection between the first and second audio signals in the frequency domain, wherein the two audio signals are processed by the signal processing module (e.g., signal processing module 210 or 310) and output to the bone conduction vibration element and the air conduction vibration element. The first audio signal comprises a first frequency band (e.g., in the mid- or high-frequency range) containing frequency components with frequencies above the frequency cutoff point. The second audio signal comprises a second frequency band (e.g., in the low- or mid-frequency range) containing frequency components with frequencies below the frequency cutoff point.

[0043] It should be noted that the frequency cutoff point in this description can be measured using the following method: Lines are inserted from an output end of the signal processing module and connected in parallel to the input ends of the bone conduction vibration element and the air conduction vibration element. Using a sound card and the Audition software, electrical signals from two groups can be recorded and converted into the frequency domain. The electrical signals from each group correspond to a frequency-domain curve, the intersection of which is the frequency cutoff point.

[0044] In some embodiments, the signal processing module 310 is designed to determine, based on the frequency cutoff point, the components with frequencies in the first frequency band (i.e., the first audio signal) and the components with frequencies in the second frequency band (i.e., the second audio signal) in the original audio signals. The bone conduction vibrating element 321 vibrates in response to the first audio signal to generate the bone conduction sound waves in the first frequency band. Conversely, the air conduction vibrating element 322 vibrates in response to the second audio signal to generate the air conduction sound waves in the second frequency band.

[0045] It should be noted that sound in the second frequency band (e.g., low and mid frequencies) is emitted as air conduction sound waves because the air load driven by the air conduction vibration element is smaller, which contributes to reducing the power consumption of the acoustic output device 100. Furthermore, this ensures that sound loss from the acoustic output device 100 below a certain frequency in the second frequency band is less perceptible to the human ear. This minimizes the impact on the listening experience and the user's privacy. In contrast, sound in the first frequency band (e.g., mid and high frequencies) is emitted as bone conduction sound waves. Here, the sound is transmitted via the user's bones, tissues, etc., to the user's cochlea, so sound loss occurs only very rarely.Even with an increase in the acoustic output of the acoustic output device 100, no significant sound loss occurs on this basis. Furthermore, the perceptible vibrations generated by the oscillation of the bone conduction vibration element can be reduced, and the user experience improved, by providing acoustic output in the mid- and high-frequency ranges through the bone conduction vibration element.

[0046] See Fig. 4 and Fig. 5. To adjust the output characteristics (such as the frequency, phase, amplitude, etc. of the emitted bone conduction or air conduction sound waves) of the bone conduction vibration element and / or the air conduction vibration element, the original audio signals can be processed in the signal processing module 210 or 310, so that the first audio signal and / or the second audio signal are obtained, allowing the bone conduction vibration element and / or the air conduction vibration element to have different output characteristics. For example, the first audio signal and / or the second audio signal can be a signal within a specific frequency range.In some alternative embodiments, the structure of at least one assembly of the output module 220 or 320 can be modified or optimized, thereby allowing the output characteristics (for example, the frequency range of the emitted sound waves) of the bone conduction vibration element and / or the air conduction vibration element to be adjusted.

[0047] In some embodiments, the signal processing module 210 or 310 can process the original audio signals using hardware, software (algorithms), or a combination of both. For example, the signal processing module 210 can include an amplifier 211. The signal processing module 210 can amplify a specific signal (for example, the original audio signals) via the amplifier 211 (or an amplifier circuit) and / or an amplification algorithm. Furthermore, the signal processing module 210 can, for example, include an equalizer 212. The equalizer 212 serves to equalize a signal (for example, the filtered original audio signals). Additionally, the signal processing module 210 can, for example, include a filter 213. The filter 213 serves to filter the original audio signals 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), and the like.

[0048] In some embodiments, the signal processing module 210 or 310 can process the original audio signals using 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, or the like, or a combination thereof. For example, the signal processing module includes a high-pass filter and a low-pass filter. Thus, the signal processing module can process the original audio signals through the high-pass filter to obtain the first audio signal. It can also process the original audio signals through the low-pass filter to obtain the second audio signal.

[0049] In some embodiments, the cutoff frequency of the low-pass filter can be identical to that of the high-pass filter. After processing by the low-pass filter, a portion of the original audio signals above the cutoff frequency (i.e., the frequency separation point) is filtered out, thus preserving primarily the low-frequency components below the cutoff frequency (i.e., the second audio signal). Similarly, after processing by the high-pass filter, a portion of the original audio signals below the cutoff frequency (i.e., the frequency separation point) is filtered out, thus preserving primarily 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 can differ from that of the high-pass filter.In this case, the frequency cutoff point refers to an intersection in the frequency range between the first audio signal and the second audio signal, with the two audio signals being output to the bone conduction vibration element and the air conduction vibration element, respectively.

[0050] It should be noted that in practical application, the first and second audio signals processed and received by the signal processing module 210 or 310 may exhibit some frequency overlap near the frequency crossover point. Furthermore, the frequency range of the bone conduction sound waves generated by the bone conduction vibration element in response to the first audio signal corresponds to the frequency range of the first audio signal. Similarly, the frequency range of the air conduction sound waves generated by the air conduction vibration element in response to the second audio signal corresponds to the frequency range of the second audio signal. This could therefore lead to an overlap of the bone conduction and air conduction sound waves generated by the bone conduction and air conduction vibration elements, respectively, within a certain frequency band.This means that both air conduction and bone conduction sound waves are present in this overlapping frequency band.

[0051] For bone conduction and air conduction sound waves, the acoustic properties such as in-phase reinforcement and out-of-phase cancellation are fulfilled at the cochlea. This means that sound with the same or essentially the same phase superimposes at the cochlea, thus increasing the audibility for the user. Conversely, sound with opposite or essentially opposite phase cancels out at the cochlea, which could reduce the audibility for the user.To prevent the cancellation effect in the overlapping frequency band for bone conduction and air conduction sound waves, and thus the reduction in audibility for the user, the phases of the first and second audio signals can be controlled with respect to their overlapping frequency components in the embodiments described above so that they are equal or substantially equal. This allows for a stronger superposition of the effects of generated bone conduction and air conduction sound waves at the user's cochlea, ensuring that the acoustic output device can consistently produce robust sound in the frequency band sensitive to the human ear (e.g., 20 Hz to 4000 Hz), resulting in enhanced audibility for the user.

[0052] Fig. Figure 6 shows a schematic representation of frequency response curves or corresponding phase curves of a bone conduction vibration element and an air conduction vibration element according to some embodiments of the present description.

[0053] With reference to Fig. Figure 61 represents the frequency response curve of the air conduction vibration element, and curve 63 represents the phase curve of the air conduction sound waves. Curve 62 represents the frequency response curve of the bone conduction vibration element, while curve 64 represents the phase curve of the bone conduction sound waves. As in Fig. As shown in Figure 6, the bone conduction vibration element exhibits a first resonance peak 621 at a first resonance frequency (e.g., 250 Hz), with its first high-frequency mode occurring only above 7000 Hz. In particular, the first high-frequency mode of the bone conduction vibration element can be exemplified by its frequency response curve exhibiting a trough at approximately 9000 Hz and subsequently a resonance peak at approximately 11 kHz, as shown in Figure 6. Fig. Figure 6 illustrates this. The air conduction vibration element exhibits a second resonance peak 611 at a second resonance frequency (e.g., 300 Hz), which can be considered the first resonance peak generated by the air conduction vibration element, and a third resonance peak 612 (i.e., a first high-frequency resonance peak of the air conduction vibration element) at a third resonance frequency (e.g., 4200 Hz). In some embodiments, the first resonance peak 621 may be a first resonance peak generated by the bone conduction vibration element in the frequency domain, i.e., a resonance peak with a lowest resonance frequency. The second resonance peak 611 may be a first resonance peak generated by the air conduction vibration element in the frequency domain, i.e., a resonance peak with a lowest resonance frequency.

[0054] In conjunction with the frequency response curve 62 and the phase curve 64 of the bone conduction vibration element, it can be seen that a bone conduction signal exhibits a relatively stable phase between the frequency bands that correspond to the bone conduction vibration element before the occurrence of the first resonance peak 621 and the first high-frequency mode. In conjunction with the frequency response curve 61 and the phase curve 63 of the air conduction vibration element, it can be seen that the corresponding air conduction sound waves exhibit a relatively stable phase between the second resonance peak 611 and the third resonance peak 612 (i.e., the first high-frequency resonance peak) of the air conduction vibration element.

[0055] In some embodiments, the phases of the bone conduction and air conduction sound waves must be kept equal or substantially equal in an overlapping frequency band to allow for a stronger superposition of the effects of the bone conduction and air conduction sound waves generated by the acoustic output device in this overlapping frequency band at the user's cochlea. In this case, the frequency crossover point of the first audio signal and the second audio signal can be kept in a frequency band in which the phases of the bone conduction vibration element and the air conduction vibration element are relatively stable.This helps ensure that the first and second audio signals, processed by hardware, software, or a combination thereof, remain stably equal or substantially equal within this frequency band, where a relatively stable phase is guaranteed. This achieves phase-matched amplification through the effects of bone conduction and air conduction sound waves at the user's cochlea, thereby improving the audibility for the user.

[0056] To ensure better acoustic output from the acoustic output device in the low frequency band (e.g., 300 Hz to 1000 Hz), the phases of the bone conduction and air conduction sound waves must be kept relatively stable in some embodiments when the frequency cutoff point lies in this low frequency band. Since the bone conduction and / or air conduction sound waves exhibit significant phase fluctuations before reaching the frequencies corresponding to their respective first resonance peaks (i.e., the first resonance frequency and / or the second resonance frequency), the frequency cutoff point can therefore be higher than the first or second resonance frequency, i.e., it can be higher than the higher of the first and second resonance frequencies. To achieve better acoustic output from the acoustic output device in the higher frequency band (e.g.,To ensure stability within the 2500 Hz to 5000 Hz range, in some embodiments the phases of the bone conduction and air conduction sound waves must be kept relatively stable when the frequency cutoff point lies in this higher frequency band. 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, and the air conduction sound waves exhibit significant phase fluctuations after reaching the frequency corresponding to the first high-frequency resonant peak of the air conduction vibrator (i.e., the third resonant frequency), the frequency cutoff point can therefore be lower than the first high-frequency resonant frequency of the bone conduction vibrator or the first high-frequency resonant frequency (i.e., the third resonant frequency) of the air conduction vibrator., it can be lower than the lower of the first high-frequency resonant frequency of the bone conduction vibration element and the first high-frequency resonant frequency (i.e., the third resonant frequency) of the air conduction vibration element.

[0057] To ensure better acoustic output from the acoustic output device in the frequency band sensitive to the human ear (e.g., 300 Hz to 3500 Hz), the phases of the bone conduction and air conduction sound waves must be kept relatively stable in some embodiments when the frequency cutoff point lies within this frequency band sensitive to the human ear. Since the phase of the bone conduction sound waves is stable between the first resonant frequency and its first high-frequency resonant frequency, and the phase of the air conduction sound waves is stable between the second and third resonant frequencies, and since the first high-frequency resonant frequency of the bone conduction vibrating element is higher than the third resonant frequency of the air conduction vibrating element, the frequency cutoff point therefore lies in the frequency range between the second resonant frequency or between the first and third resonant frequencies.For better understanding, this will be discussed in conjunction with . Fig. 7 described. Since, at the higher first resonance frequency F1 compared to the second resonance frequency F2 (or at the higher second resonance frequency F2 compared to the first resonance frequency F1), the first high-frequency resonance frequency of the bone conduction vibration element is higher than the first high-frequency resonance frequency (i.e., the third resonance frequency F3) of the air conduction vibration element, the frequency cutoff point F4 is higher than the first resonance frequency F1 (or the second resonance frequency F2) and the frequency cutoff point F4 is lower than the first high-frequency resonance frequency (i.e., the third resonance frequency F3) of the air conduction vibration element. To achieve a better acoustic output effect of the acoustic output device in the frequency band sensitive to the human ear (e.g.,To ensure accuracy (300 Hz to 3500 Hz), the frequency cutoff point F4 lies in the frequency range between the first resonant frequency F1 (or the second resonant frequency F2) and the third resonant frequency F3. For a description of the third resonant frequency, reference can be made to... Fig. 11 and their description are referenced.

[0058] In some embodiments of this description, the frequency cutoff point is set in the phase curves of the bone conduction and air conduction vibration elements within a region where the phases remain relatively stable. This ensures that the phases of the bone conduction and air conduction sound waves tend to remain stable near the frequency cutoff point. Thus, it is easily ensured that the bone conduction and air conduction sound waves have the same phase. Furthermore, this guarantees that sound signals near the frequency cutoff point do not exhibit abrupt drops (e.g., no "concave" shape of the frequency response curve near the frequency cutoff point) compared to the preceding or subsequent frequency bands.Consequently, a “superposition” of bone conduction and air conduction sound waves is achieved near the frequency cut-off point, resulting in an effect of phase-in-phase amplification.

[0059] Since the acoustic output device in some embodiments uses the air conduction vibration element for low- or medium-frequency output and the bone conduction vibration element for medium- or high-frequency output, the second resonance frequency F2 should be determined with further reference to Fig. 6 and Fig. 7. The first resonant frequency, F1, should be as low as possible to ensure effective output from the acoustic output device at low frequencies. Simultaneously, the first resonant frequency, F1, should not be too low in order to improve the transmission of bone-conducted sound via the bone conduction vibration element in the mid- to high-frequency range. At this point, the second resonant frequency, F2, can be set lower than the first resonant frequency, F1. This allows the air conduction vibration element to output air-conducted sound with a larger sound pressure amplitude in the low-frequency range, while simultaneously the bone conduction vibration element outputs bone-conducted sound with a larger sound pressure amplitude in the mid- to high-frequency range. For example, the first resonant frequency, F1, is intended to be in the range of 300 Hz to 500 Hz, and the second resonant frequency, F2, in the range of 100 Hz to 300 Hz.For example, it is also planned that the first resonant frequency F1 is in the range of 300 Hz to 400 Hz and the second resonant frequency F2 is in the range of 150 Hz to 250 Hz.

[0060] In some embodiments described above, the second resonant frequency is set lower than the first resonant frequency to ensure that the air conduction vibration element can produce a relatively stronger output even in a lower frequency range. This ensures that the low-frequency output of the air conduction vibration element can cover a wider low-frequency range. Thus, the acoustic output device can provide a high acoustic output across a broad frequency range, thereby ensuring improved acoustic effectiveness within the hearing threshold (e.g., 20 Hz to 5000 Hz).

[0061] For certain scenarios where vibration output is required, such as simulating gunshots in games, vehicle vibrations, or vibration feedback for alarm tones, the second resonant frequency F2 can be set higher than the first resonant frequency F1 in some embodiments. This allows the acoustic output device to emit sound while simultaneously adapting better to the application scenarios, thus improving the user experience. Setting the second resonant frequency F2 higher than the first resonant frequency F1 in some embodiments also improves the sensitivity of the air-conducting vibration element to mid-frequencies, thereby reducing overall power consumption at high volumes and increasing the operating time of the acoustic output device. Furthermore, it can also improve reliability against mechanical shocks such as drops.

[0062] Fig. Figure 8 shows a schematic sectional view of the core assembly according to some embodiments of the present description in a section direction BB.

[0063] Combined with Fig. 3 and Fig. Figure 8 shows that in some embodiments, the bone conduction vibration element 11 comprises a vibration plate 111. The vibration plate 111 generates mechanical vibrations in a first vibration direction X1, i.e., in a direction perpendicular to the plane of the drawing, when driven by the first audio signal. The vibrations of the vibration plate 111 come into contact with the user's skin via the housing 10, thereby transmitting bone conduction sound waves to the user. The first resonant frequency F1 of the bone conduction vibration element 11 is related to the vibration plate 111, the housing 10, a magnetic circuit system (e.g., a magnetically conductive cover, a magnet, a coil, etc.) of the bone conduction vibration element 11, and a vibration system formed by a vibration transmission structure between the vibration plate 111 and the housing 10.The resonant frequency of the aforementioned vibration system can be considered the first resonant frequency F1 of the bone conduction vibration element 11. In practical application, it should be noted that the acoustic output device 100 is formed by integrating the air conduction vibration element 12 with the bone conduction vibration element 11, so that when the bone conduction vibration element 11 vibrates, the air conduction vibration element 12 can act as a load on the bone conduction vibration element 11. Therefore, the air conduction vibration element 12 could influence the first resonant frequency F1 of the bone conduction vibration element 11 (for example, through its mass, the direction of vibration of the membrane, etc.).In this case, the first resonance frequency F1 of the bone conduction vibration element 11 can be related to the above-mentioned vibration system and the air conduction vibration element 12, whereby the resonance frequency of the vibration system or of the air conduction vibration element 12 can be considered as the first resonance frequency F1 of the bone conduction vibration element 11.

[0064] Combined with Fig. 3 and Fig. In some embodiments, the air conduction vibration element 12 comprises a diaphragm 121. The diaphragm 121 divides the receiving chamber 1002 into a rear chamber 1004 and a front chamber 1003, located on opposite sides of the diaphragm 121. The rear chamber 1004 is located on the side of the diaphragm 121 facing away from the partition 1012, and the front chamber 1003 is located between the diaphragm 121 and the partition 1012. The second audio signal drives the diaphragm 121 to generate mechanical vibrations in a second direction of vibration X2, thereby generating air conduction sound waves through propagation via media such as air. The second resonance frequency F2 of the air conduction vibration element 12 is related to the properties of the membrane 121, whereby the resonance frequency of the membrane 121 can be considered as the second resonance frequency F2 of the air conduction vibration element 12.

[0065] In the low-frequency range, the vibration of the bone conduction vibrator 11 in the frequency range near its first resonant frequency F1 generally results in a strong vibration sensation in the user's face. As the frequency of the bone conduction sound waves emitted by the bone conduction vibrator 11 increases, the vibration sensation in the user's face caused by the bone conduction vibrator 11 gradually decreases. For example, the bone conduction vibrator produces a pronounced vibration sensation (e.g., like a slap in the face) in the range of 150 Hz to 300 Hz, a relatively weaker vibration sensation (e.g., a tingling sensation) in the range of 300 Hz to 400 Hz, and a relatively quiet vibration sensation in the range of 400 Hz to 600 Hz.Therefore, in some embodiments, the frequency cutoff point can be set to no lower than 300 Hz to prevent the bone conduction vibration element 11 from generating excessively strong vibrations due to an output frequency that is too low, thus preventing an adverse user experience. In some embodiments, the frequency cutoff point can be set to no lower than 350 Hz to further dampen the vibration sensation generated by the bone conduction vibration element 11. In some embodiments, the frequency cutoff point can be set to no lower than 400 Hz. In some embodiments, the frequency cutoff point can be set to no lower than 500 Hz.

[0066] In some embodiments described above, setting the frequency crossover point to no lower than 300 Hz prevents the bone conduction vibration element from generating excessive low-frequency vibrations. This avoids an adverse user experience due to an excessively strong vibration sensation and ensures the low-frequency performance of the acoustic output device.

[0067] Starting from the first resonant frequency F1 or the second resonant frequency F2, the phase of bone conduction sound waves or the phase of air conduction sound waves tends to remain stable with increasing frequency. As in Fig. As shown in Figure 6, for example, the phase of bone conduction sound waves (corresponding to curve 64) is designed to gradually decrease in the frequency range from 250 Hz to 350 Hz. Starting from a frequency of 350 Hz, the phase of bone conduction sound waves tends to remain stable. Similarly, the phase of air conduction sound waves (corresponding to curve 63) is designed to gradually decrease in the frequency range from 200 Hz to 300 Hz. Starting from a frequency of 300 Hz, the phase of air conduction sound waves tends to remain stable. It should be noted that the stabilization of the phase of bone conduction or air conduction sound waves may refer to phase fluctuations of bone conduction or air conduction sound waves that are below a certain degree, for example 30 degrees, 20 degrees, 10 degrees, etc.

[0068] To further ensure that the bone conduction and air conduction sound waves exhibit phase-coherent amplification within the frequency band near the crossover point, the crossover point can, in some embodiments, be positioned outside the frequency band near the first resonant frequency F1 or the second resonant frequency F2, where the phase continues to gradually increase or decrease. This allows the crossover point to lie within a frequency band in which the phase of both the bone conduction and air conduction sound waves remains stable. The crossover point can be located behind the first resonant frequency F1 and the second resonant frequency F2, and at a distance from both.For example, the difference between the first resonant frequency F1 and the frequency cutoff point, as well as the difference between the second resonant frequency F2 and the frequency cutoff point, is each not less than 100 Hz. In other words, the difference between the higher of the first resonant frequency F1 and the second resonant frequency F2 and the frequency cutoff point is not less than 100 Hz. In some embodiments, the difference between the higher of the first resonant frequency F1 and the second resonant frequency F2 and the frequency cutoff point can be set to not less than 200 Hz to allow the frequency cutoff point to lie within a frequency band in which the phases of the bone conduction and air conduction sound waves remain more stable (for example, the bone conduction and air conduction sound waves have a phase difference of less than 20 degrees).In some embodiments, the difference between the higher of the first resonant frequency F1 and the second resonant frequency F2 and the frequency cut-off point can be set to no less than 300 Hz to allow the frequency cut-off point to lie within a frequency band in which the phases of the bone conduction and air conduction sound waves remain particularly stable (for example, the bone conduction and air conduction sound waves have a phase difference of less than 10 degrees).

[0069] In some embodiments described above, the difference between the first or second resonant frequency and the frequency cutoff point is kept within a certain threshold range. This advantageously ensures that the sound wave phase within the frequency band near the frequency cutoff point lies within a stable interval. Furthermore, this can prevent fluctuations in the resonant frequencies of bone conduction / air conduction vibration elements in manufactured devices from different batches, which arise from differences in the manufacturing process. This avoids phase deviations between the bone conduction and air conduction sound waves within the frequency bands near the respective frequency cutoff points in devices from different batches.This ensures the output power of the acoustic output device and improves the output stability of the manufactured acoustic output device.

[0070] Since the air load driven by the air-conducting vibration element is smaller, and thus power consumption can be effectively reduced, the frequency crossover point in some embodiments can be set in the higher frequency band, for example, between 1000 Hz and 2000 Hz, between 1500 Hz and 2500 Hz, etc., so that the acoustic output of the acoustic output device is more in the form of air-conducted sound waves, thereby reducing the acoustic output device's power consumption. However, in this case, air-conducted sound near the frequency crossover point with a frequency below the crossover point is relatively sensitive to the human ear. This means that sound leakage from the acoustic output device is easily perceived by people in the vicinity. This can impair the listening experience and the user's listening privacy.

[0071] Thus, in some exemplary embodiments, with further reference to Fig. It is provided that, to reduce the sound loss of the acoustic output device, the housing 10 (such as the first housing 101, the second housing 102, and / or the third housing 103) of the acoustic output device 100 may be provided with a first sound guide opening 1080 and a second sound guide opening 1081. The first sound guide opening 1080 connects the rear chamber 1004 to the outside environment, while the second sound guide opening 1081 connects the front chamber 1003 to the outside environment. The first sound guide opening 1080 serves to guide and output the air-conducting sound waves generated by the air-conducting vibration element 12, while the second sound guide opening 1081 serves to relieve pressure on the air-conducting vibration element 12, thereby ensuring stable normal operation of the air-conducting vibration element 12.In some embodiments, the air conduction vibration element 12 can radiate sound with the same amplitude and opposite phase into the external environment via the two sound conduction openings (i.e., the first sound conduction opening 1080 and the second sound conduction opening 1081). In this case, a dipole output structure can be formed by the first sound conduction opening 1080 and the second sound conduction opening 1081, thus reducing the sound loss of the air conduction vibration element 12 in the far field and thereby improving the listening experience and the user's listening privacy.

[0072] Fig. Figure 9 shows a schematic representation of an exemplary sound field of a dipole according to some embodiments described in the present text. It refers to Fig. 9. The air-conduction sound waves emitted by the acoustic output device are directed along the first sound guide opening 1080 and the second sound guide opening 1081. The first sound guide opening and the second sound guide opening can be considered as the first sound source AS1 and the second sound source AS2 with the same (or substantially the same) amplitude and opposite (or substantially opposite) phase. A dipole 2 or a dipole-like structure consists of the first sound source AS1 and the second sound source AS2. As in Fig. As shown in Figure 9, a roughly figure-eight-shaped radiation sound field can be formed by the dipole 2 or the dipole-like structure. The intensity of the sound radiated by the sound guide openings is greatest in a straight line along the direction of the connecting line between the first sound guide opening 1080 and the second sound guide opening 1081. In all other directions, the sound radiation is significantly reduced. Thus, the intensity of the sound radiated into the environment by the acoustic output device (i.e., the sound loss in the far field) can be reduced by providing at least two sound guide openings in the acoustic output device to create a dipole or dipole-like structure.

[0073] In some embodiments, it is thus provided that the amplitude difference between the sound radiated through the two sound guide openings is set to less than 6 dB (e.g. to 1 dB, 3 dB or 5 dB etc.) and the phase difference between the sound radiated through the two sound guide openings can be set in the range of 150° to 210° so that the first sound guide opening 1080 and the second sound guide opening 1081 can form a dipole or a dipole-like structure to improve the ability of the acoustic output device to reduce sound loss.In some embodiments, the sounds emitted through the two sound guide openings are provided to have an amplitude difference of less than 5 dB and a phase difference of 160° to 200°, so that the first sound guide opening 1080 and the second sound guide opening 1081 can form a standardized, dipole-like structure to further improve the acoustic output device's ability to reduce sound loss. In some embodiments, the sounds emitted through the two sound guide openings are provided to have an amplitude difference of less than 3 dB and a phase difference of 170° to 190°. In some embodiments, the sounds emitted through the two sound guide openings are provided to have an amplitude difference of less than 3 dB and a phase difference of 175° to 185°.In some embodiments, the near-field sound pressure level difference between the two sound guide openings can be set to less than 6 dB, so that the sound radiated through the two sound guide openings has an amplitude difference of less than 6 dB. It is understandable that the cancellation effect achieved by sound waves with the same amplitude and opposite phase in the far field is more pronounced the smaller the near-field sound pressure level difference, thus improving the effect on reducing sound loss.

[0074] In this description, the near-field sound pressure level difference refers to the difference in the sound pressure levels of the sound radiated from each of the two sound guide openings to the near-field position. A near-field position for a sound guide opening can be a position within a distance of 5 mm from that opening. For better understanding, the near-field sound pressure level difference can be expressed as the difference in sound pressure levels at the two sound guide openings of the acoustic output device 100.

[0075] In some embodiments, the near-field sound pressure level test can be performed as follows: At a specific frequency point (e.g., 1000 Hz), the sound pressure of the sound emitted through the first and second sound guide openings is measured. The difference between the sound pressure levels of the first and second sounds is then calculated (the sound pressure level is obtained, for example, from the base-10 logarithm of the measured sound pressure to the reference sound pressure, multiplied by 20). In some embodiments, it is provided that when testing the sound from the first (or second) sound guide opening, the first and second sound guide openings can be separated by the baffle to prevent the second (or first) sound guide opening from interfering with the test.The sound pressure at the first sound guide aperture can be understood as the sound pressure at the position near the first sound guide aperture, and the sound pressure at the second sound guide aperture can be understood as the sound pressure at the position near the second sound guide aperture. For example, a sound detection device can be positioned 4 mm from the first sound guide aperture (or the second sound guide aperture) to detect the first sound (or the second sound) as the sound pressure at the first sound guide aperture (or the second sound guide aperture).

[0076] In some embodiments, when testing sound from the first and second sound guide openings, the positions (i.e., the detection positions), located 4 cm from each of these openings, can be situated in two opposite directions from the acoustic output device 100 (for example, the position 4 cm from the first sound guide opening is located in the direction from the second sound guide opening to the first sound guide opening, while the position 4 cm from the second sound guide opening is located in the direction from the first sound guide opening to the second sound guide opening). A sound detection device is arranged at each of the two detection positions to detect the sound pressure levels of the acoustic output device 100.In addition, the difference between the two sound pressure levels, i.e. the near-field sound pressure level difference between the first sound guide opening and the second sound guide opening, is calculated.

[0077] In this process, the first and second sound waves can effectively interfere with each other in a specific direction in the far field and cancel each other out, by controlling the near-field sound pressures of the sound emitted through the first sound guide aperture and the sound emitted through the second sound guide aperture so that they are approximately equal. This effectively reduces the sound loss of the acoustic output device 100 in the far field.

[0078] In some embodiments described above, the air conduction vibration element emits sound at a low or medium frequency, while the bone conduction vibration element emits sound at a medium or high frequency, thus reducing the sensation of vibration generated by the acoustic output device. Furthermore, by setting the frequency crossover point at a higher frequency, the acoustic output of the device is more in the form of air conduction sound waves, which reduces the device's power consumption. Simultaneously, a dipole or dipole-like structure can be formed by the two sound guide openings, provided that the amplitude and phase differences of the sounds emitted by the two openings meet certain conditions.This improves the acoustic output device's ability to reduce sound loss in the low to mid frequency range.

[0079] In some embodiments, the near-field sound pressure level difference can be adjusted by modifying the difference between the acoustic loads of the two sound guide openings. The acoustic load is the ratio of a sound pressure value P1 after passing through the sound guide opening to the sound pressure value P0 before passing through the sound guide opening; that is, the acoustic load equals P1 / P0. It should be noted that with a given acoustic load at a specific sound guide opening, the sound resistance decreases the larger the acoustic load is (or the closer it is to 1).

[0080] In some embodiments, the acoustic load can be based on measurements of a sound pressure level (corresponding to P1) at the sound guide opening covered with gauze and a sound pressure level (corresponding to P0) at the sound guide opening uncovered by gauze at a specific distance. The acoustic load of the sound guide opening is then determined by calculating the ratio of P1 to P0. When testing the sound emanating from the sound guide opening, the sound detection device can be positioned at a distance of 4 to 5 mm from the opening. Subsequently, the sound pressure level (corresponding to P1) at the sound guide opening covered with gauze and the sound pressure level (corresponding to P0) at the sound guide opening uncovered by gauze are recorded. Finally, the acoustic load of the sound guide opening is determined by calculation.It should be noted that a single-frequency signal can be used for the acoustic load test signal, whereby one or more frequency points can be selected, including but not limited to 100 Hz, 200 Hz, 300 Hz, 500 Hz, 1000 Hz, 2000 Hz, 5000 Hz, and the resonant frequency of the acoustic output device, etc. A white or pink noise signal or a sweep signal can also be selected as the test signal. It should be noted that in some embodiments it is necessary to convert the measured sound pressure level into the sound pressure value. The acoustic load is then determined by calculation. Alternatively, the sound pressure levels measured before and after covering the sound guide opening with gauze can be subtracted. The value of the acoustic load of the sound guide opening can then be calculated using a logarithmic formula.

[0081] In some embodiments, the difference between the acoustic loads of the two sound guide openings can be 0.1, 0.15, 0.2, etc. In other embodiments, the difference between the acoustic loads of the two sound guide openings can be less than 0.15. It is understandable that the acoustic resistances of the two sound guide openings are more similar the smaller the difference between their acoustic loads. This reduces the near-field sound pressure level difference between the two sound guide openings, thus increasing the effect of reducing sound loss in the far field.

[0082] Furthermore, it is intended that the difference between the acoustic loads of the two sound guide openings can be less than 0.1. By further reducing the range of values ​​for the difference between the acoustic loads of the two sound guide openings, the near-field sound pressure level difference between the two sound guide openings can be reduced, thereby further improving the effect of reducing sound loss in the far field. To reduce the power consumption of the acoustic output device 100, the frequency crossover point can be shifted towards higher frequencies. When the frequency crossover point is shifted towards higher frequencies, the air-conducted sound waves emitted by the acoustic output device 100 contain more high-frequency components. This gradually increases the sound loss of the acoustic output device 100 in the far field.By shifting the frequency separation point towards higher frequencies, the difference between the acoustic loads of the two sound guide openings can be reduced, further improving the effect of reducing sound loss in the far field to ensure the output performance of the acoustic output device 100.

[0083] To reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set between 300 Hz and 1 kHz in some embodiments. To reduce the far-field sound loss of the acoustic output device 100, the difference between the acoustic loads of the two sound guide openings can be in the range of 0 to 0.12. To further reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set between 1 kHz and 2 kHz in some embodiments. To further reduce the far-field sound loss of the acoustic output device 100 (or the air guide vibration element 12), the difference between the acoustic loads of the two sound guide openings can be in the range of 0 to 0.1. To further reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set between 1.5 kHz and 2.5 kHz in some embodiments.To reduce the sound loss of the acoustic output device 100 (or the air-conducting vibration element 12) in the far field, the difference between the acoustic loads of the two sound-conducting openings can be in the range of 0 to 0.07. To reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set between 2 kHz and 3 kHz in some embodiments. To further reduce the sound loss of the acoustic output device 100 (or the air-conducting vibration element 12) in the far field, the difference between the acoustic loads of the two sound-conducting openings can be in the range of 0 to 0.05.

[0084] In some embodiments, the near-field sound pressure level difference can also be adjusted by adjusting the ratio between the acoustic surface loads of the two sound guide openings.

[0085] The acoustic surface load is the product of the ratio of the sound pressure value P1 after passing through the sound guide opening to the sound pressure value P0 before passing through the sound guide opening and the area S of the sound guide opening, i.e., the acoustic surface load corresponds to S×P1 / P0.

[0086] In some embodiments, the ratio between the acoustic surface loads of the two sound-guiding openings can be 0.5, 1, 2.5, etc. In other embodiments, the ratio between the acoustic surface loads of the two sound-guiding openings can range from 0.5 to 3.5. By adjusting the ratio between the acoustic surface loads of the two sound-guiding openings to maintain it within a reasonable range, the acoustic resistances of the two sound-guiding openings can be more closely matched. This reduces the near-field sound pressure level difference between the two sound-guiding openings, thereby improving the effect of reducing sound loss in the far field.

[0087] Furthermore, it is intended that the ratio between the acoustic surface loads of the two sound-guiding openings can range from 0.8 to 2. It is understandable that further reducing the range of values ​​for the ratio between the acoustic surface loads of the two sound-guiding openings can increase the effect of reducing sound loss in the far field. To reduce the power consumption of the acoustic output device 100, the frequency crossover point can be shifted towards higher frequencies. When the frequency crossover point is shifted towards higher frequencies, the air-conducted sound waves emitted by the acoustic output device 100 contain more high-frequency components. This gradually increases the sound loss of the acoustic output device 100 in the far field.By shifting the frequency separation point towards higher frequencies, the ratio between the acoustic surface loads of the two sound guide openings can be reduced, thereby further improving the effect of reducing sound loss in the far field to ensure the output performance of the acoustic output device 100.

[0088] To reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set between 300 Hz and 1 kHz in some embodiments. To reduce the far-field sound loss of the acoustic output device 100, the ratio between the acoustic surface loads of the two sound guide openings can be in the range of 0.5 to 3.5. To further reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set between 1 kHz and 2 kHz in some embodiments. To reduce the far-field sound loss of the acoustic output device 100 (or the air guide vibration element 12), the ratio between the acoustic surface loads of the two sound guide openings can be in the range of 0.6 to 2.7.To further reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set between 1.5 kHz and 2.5 kHz in some embodiments. To reduce the sound loss of the acoustic output device 100 (or the air-conducting vibration element 12) in the far field, the ratio between the acoustic surface loads of the two sound-conducting openings can be in the range of 0.7 to 2. To further reduce the power consumption of the acoustic output device 100, the frequency crossover point can be set in the range of 2 kHz to 3 kHz in some embodiments. To reduce the sound loss of the acoustic output device 100 (or the air-conducting vibration element 12) in the far field, the ratio between the acoustic surface loads of the two sound-conducting openings can be in the range of 0.9 to 1.2.

[0089] In some embodiments described above, the range of values ​​for the difference between the acoustic loads and / or the ratio between the acoustic surface loads of the two sound guide openings is adjusted so that the acoustic resistances of the two sound guide openings can be more closely matched, thereby reducing the near-field sound pressure level difference between the two sound guide openings. This allows the dipole or dipole-like structure to be constructed to further improve the effect of reducing sound loss in the far field.

[0090] In some embodiments, the sound loss generated by the air-conduction sound waves could impair the listening experience and the user's privacy if the acoustic output device performs the acoustic output in the form of air-conduction sound waves in the higher frequency band (e.g., in the range of 500 Hz to 3000 Hz). To further reduce the sound loss of the acoustic output device, in some embodiments the first sound-conduction opening 1080 and the second sound-conduction opening 1081 can therefore be adapted to radiate sound with a phase and / or amplitude difference into the external environment. This adjusts the sound field radiated by the dipole or dipole-like structure.In particular, by controlling the amplitude difference and phase difference of the two sounds emitted by the acoustic output device, the extent of mutual cancellation of the sound emitted by the acoustic output device in the far field can be changed. If this phase difference meets certain conditions, the sound loss emitted in the opposite direction from the acoustic output device can be suppressed, while a high output volume from the acoustic output device in a specific direction (for example, towards the user's ear canal opening R1) is maintained. In this case, the sound field emitted through the first sound guide opening 1080 and the second sound guide opening 1081 is in . Fig. 10 shown.

[0091] Fig. Figure 10 shows a schematic representation of an exemplary directed radiation sound field of the acoustic output device according to some embodiments described in this document. It refers to Fig. 10. The first sound source AS1 generates the first sound, and the second sound source AS2 generates the second sound. If the first and second sounds have a certain amplitude and / or phase difference, the first sound source AS1 and the second sound source AS2 can form a highly directional sound radiation field. This strong directivity can manifest itself in the sound radiated from the two sound guide openings exhibiting a far-field sound pressure level difference of at least 3 dB in at least one pair of opposite directions (e.g., towards the ear canal and the opposite direction). This allows for greater volume in the direction of the user's ear canal, while reducing sound loss in the opposite direction to the user's ear canal and in other directions.Consequently, a better balance can be achieved between maintaining an open ear canal and ensuring listening privacy. As exemplified by... Fig. As can be seen in Figure 10, the emitted sound field with strong directionality has only one main lobe. The sound field radiation within and near this main lobe is relatively strong, while the sound field radiation in other directions is weaker (with the sound field intensity in the direction opposite to the main lobe also being comparatively low). When the user wears the acoustic output device, the main lobe can be directed towards the user's ear canal opening R1. At this point, only the radiation directed towards the ear canal opening R1 and its immediate surroundings is strong, while all other directions exhibit weak directionality. This allows for a further reduction in sound loss from the acoustic output device 100.

[0092] The far-field sound pressure level difference refers to the difference in the sound pressure amplitudes of the sound radiated from the two sound guide openings in the far field. The far field for a sound guide opening can be a position beyond a distance of 10 cm from that opening. For better understanding, the far-field sound pressure level difference between two sound guide openings can be expressed as the difference in sound pressure amplitudes measured at points (or at symmetrical positions) that are equidistant or substantially equidistant from the two openings along the line connecting them.When measuring the sound pressure amplitude of a sound guide opening, for example when detecting sound from the first sound guide opening (or from the second sound guide opening), the sound detection device can be arranged at a distance of 30 cm from the first sound guide opening (or from the second sound guide opening) in order to achieve detection.

[0093] In some embodiments, the far-field sound pressure level difference between the two sound guide openings can be controlled by adjusting the amplitude difference and the phase difference of the sound emitted through the two sound guide openings. It should be noted that the phase of the sound emitted by the sound guide opening (e.g., the first sound guide opening 1080 or the second sound guide opening 1081) described in the embodiments of this description may refer to a phase measured at a distance of 4 mm from the sound guide opening (or the geometric center of the sound guide opening), for example, 4 mm in front of the sound guide opening. In some embodiments, the phase difference can be tested as follows: First, the phase of the sound emitted through the two sound guide openings (the first and second sound, respectively) is measured.The phase difference between the first and second sound waves is then calculated. When testing the sound from the first (or second) sound guide opening, the baffle can separate the openings to prevent interference. Alternatively, the sound detection device can be positioned along the line connecting the first and second openings. In this case, the first sound wave is detected at a distance of 4 mm from the first (or second) opening, again preventing interference. For illustrative purposes only, the baffle dimensions can be selected from standard sizes.The baffle dimensions can be, for example, 1650 mm in length, 1350 mm in width, and 30 mm in height. It should also be noted that if there are two or more primary (or secondary) sound guide openings, any one of them can be selected for testing. For example, a primary and a secondary sound guide opening can be selected that are located at specific relative positions and have, for instance, the minimum or maximum relative distance. The phase of the sound emitted by each opening is then tested, and the phase difference is calculated. Furthermore, sound measurements within a specific frequency band (e.g., in the range of 0 Hz to 8000 Hz) do not need to be performed exhaustively. Instead, several (e.g.,20 to 30) frequency sampling points with equal step sizes and endpoints according to the limits of the frequency band are defined, thus enabling the measurement of the sound at each sampling point.

[0094] In some embodiments, the front chamber 1003 or the rear chamber 1004 of the air conduit vibration element 12 can form a third resonance peak with a third resonance frequency. With reference to Fig. 8. The first sound guide opening 1080 and the rear chamber 1004 can be considered approximately as a Helmholtz resonance model. In this case, the rear chamber 1004 serves as the chamber of the Helmholtz resonance model, and the first sound guide opening 1080 serves as the neck of the Helmholtz resonance model. The resonance of the Helmholtz resonance model then corresponds to the resonance frequency of the rear chamber 1004. Similarly, the second sound guide opening 1081 and the front chamber 1003 can be considered approximately as a Helmholtz resonance model. In this case, the front chamber 1003 serves as the chamber of the Helmholtz resonance model, and the second sound guide opening 1081 serves as the neck of the Helmholtz resonance model. In this case, the resonance of the Helmholtz resonance model corresponds to the resonance frequency of the front chamber 1003. For better description, the lower of the resonance frequencies of the front chamber 1003 and the rear chamber 1004 is defined as the third resonance frequency.

[0095] In the present description, the third resonance peak is measured such that, upon separation of an input signal to the bone conduction vibration element 11, a first high-frequency resonance peak of the frequency response curve of the air conduction vibration element 12 is measured, the corresponding resonance frequency of which is referred to as the third resonance frequency. Specifically, the third resonance peak of the sound generated by the front chamber 1003 or the rear chamber 1004 is measured when the first sound conduction aperture 1080 is separated from the second sound conduction aperture 1081 by the baffle.

[0096] Fig. Figure 11 shows a schematic representation of frequency response curves or corresponding phase curves of acoustic signals according to some embodiments of the present description, which are emitted through two sound guide openings coupled to a front or rear chamber of the air guide vibration element.

[0097] See Fig. 11. Curve 71 represents a frequency response curve of the first sound guide opening, curve 73 represents a corresponding phase curve of the first sound guide opening, curve 72 represents a frequency response curve of the second sound guide opening, and curve 74 represents a corresponding phase curve of the second sound guide opening. As can be seen from Fig. As can be seen in Figure 11, the amplitudes of the frequency response curves of the two sound guide openings are essentially identical (curves 71 and 72), with an amplitude deviation of approximately ± 6 dB. The phase difference between the two sound guide openings is 180° (or nearly 180°). After the third resonance peak 711, which corresponds to the third resonance frequency, the number of vibration modes on frequency response curve 71 or 72 increases. Consequently, phase jumps occur more frequently, preventing the two sound guide openings from maintaining a stable phase difference of 180° (or nearly 180°). This leads to a reduced effect of the dipole formed by the air conduction vibration element via the two sound guide openings, thus preventing an effective reduction in sound loss.If the frequency crossover point is close to the third resonant frequency, the frequent phase shifts of air-conduction sound waves make it difficult to maintain in-phase alignment between the sound waves emitted by the air-conduction and bone-conduction vibration elements. Therefore, in some embodiments, to reduce sound loss via air conduction or to maintain phase stability between bone-conduction and air-conduction sound waves near the frequency crossover point, the crossover point should be set to avoid a frequency band in which the air-conduction vibration element exhibits complex vibration modes. This means that the frequency crossover point is lower than the third resonant frequency.

[0098] By setting the frequency crossover point lower than the third resonant frequency, it can, in some embodiments described here, be shifted away from the frequency band in which the air conduction vibration element exhibits complex vibration modes. This prevents the failure to achieve an effective reduction in sound loss due to a diminished effect of the dipole formed by the air conduction vibration element via the two sound conduction openings. Simultaneously, it avoids the difficulty of keeping the sound waves emitted by the air conduction vibration element and the bone conduction vibration element in phase due to insufficient phase stability.

[0099] In some embodiments, the frequency crossover point cannot be higher than 3000 Hz to ensure that the phase difference between the two sound guide openings remains stable at 180° (or close to 180°), thus guaranteeing the effectiveness of the air duct vibration element in reducing sound loss. In some embodiments, the frequency crossover point cannot be higher than 2500 Hz to ensure the effectiveness of the air duct vibration element in reducing sound loss. In some embodiments, the frequency crossover point cannot be higher than 2000 Hz to ensure the effectiveness of the air duct vibration element in reducing sound loss.

[0100] Combined with Fig. 6 and Fig. In some embodiments, the phase of the air conduction sound waves within a frequency band upstream of the third resonant frequency F3 gradually increases with increasing frequency. That is, the phase of the air conduction sound waves upstream of the third resonant frequency F3 tends from stable to fluctuating. To more easily ensure that the bone conduction and air conduction sound waves have in-phase amplification within the frequency band near the frequency cutoff point, the frequency cutoff point F4 can therefore be set further away from the third resonant frequency F3, thus placing the frequency cutoff point F4 within a frequency band in which the phase of both the bone conduction and air conduction sound waves remains stable. For example, the difference between the third resonant frequency F3 and the frequency cutoff point F4 is not less than 500 Hz.In some embodiments, the difference between the third resonant frequency F3 and the frequency cutoff point F4 is set to at least 550 Hz to ensure that the frequency cutoff point F4 lies within a frequency band in which the phases of the bone conduction and air conduction sound waves remain more stable (for example, the bone conduction and air conduction sound waves have a phase difference of less than 20 degrees). In some embodiments, the difference between the third resonant frequency F3 and the frequency cutoff point F4 is set to at least 600 Hz to ensure that the frequency cutoff point F4 lies within a frequency band in which the phases of the bone conduction and air conduction sound waves remain particularly stable (for example, the bone conduction and air conduction sound waves have a phase difference of less than 10 degrees).In some embodiments, the difference between the third resonance frequency F3 and the frequency cutoff point F4 is set to no less than 650 Hz to make it easier to ensure that the phases of the bone conduction and air conduction sound waves remain the same.

[0101] Near the third resonant frequency, the phase of the air conduction sound waves exhibits a specific, stable frequency band. In some embodiments described here, the difference between the third resonant frequency and the frequency cutoff point is defined as no less than 500 Hz. This advantageously ensures that the sound wave phase within the frequency band near the cutoff point lies within a relatively stable interval. Furthermore, this can prevent fluctuations in the resonant frequencies of bone conduction / air conduction vibration elements in manufactured devices from different batches, which arise from variations in the manufacturing process. This avoids phase deviations between the bone conduction and air conduction sound waves within the frequency bands near the respective cutoff points in devices from different batches.This ensures the output power of the acoustic output device and improves the output stability of the manufactured acoustic output device.

[0102] As in Fig. As shown in Figure 6, the phase of the air-conducted sound waves within a frequency band before the third resonant frequency F3 gradually increases with increasing frequency. Thus, the phase of the air-conducted sound waves in the phase-stable interval differs relatively significantly from the phase at the third resonant frequency F3. In some embodiments, the difference between the phase of the air-conducted sound waves at the frequency cutoff point F4 and the phase of the air-conducted sound waves at the third resonant frequency F3 can be greater than 20° if the frequency cutoff point F4 lies in a frequency band in which the phase of the air-conducted sound waves remains stable.In some embodiments, the difference between the phase of the air conduction sound waves at the frequency cutoff point F4 and the phase of the air conduction sound waves at the third resonance frequency F3 can be greater than 30°, so that the frequency cutoff point F4 lies in a frequency band in which the phase of both the air conduction and bone conduction sound waves remains particularly stable. In some embodiments, the difference between the phase of the air conduction sound waves at the frequency cutoff point F4 and the phase of the air conduction sound waves at the third resonance frequency F3 can be greater than 50°, so that the frequency cutoff point F4 lies in a frequency band in which the phase of both the air conduction and bone conduction sound waves remains particularly stable.

[0103] As in Fig. As shown in Figure 8, in some embodiments the phase of the bone conduction sound waves emitted by the bone conduction vibration element 11 is close to the phase of the air conduction sound waves emitted by the air conduction vibration element 12 when the phase of the first audio signal is close to the phase of the second audio signal. In this case, the difference between the phases of the first and second audio signals at the frequency crossover point cannot exceed 30° in order to achieve a "superposition" of the bone conduction and air conduction sound waves and thus produce an effect of in-phase amplification. In some embodiments, the difference between the phases of the first and second audio signals at the frequency crossover point cannot exceed 20° or 10° in order to better achieve a "superposition" of the bone conduction and air conduction sound waves.

[0104] As in Fig.As shown in Figure 8, in some embodiments the difference between the phases of the bone conduction sound waves emitted by the bone conduction vibration element 11 and the air conduction sound waves emitted by the air conduction vibration element 12 can be close to 180° if the phase of the first audio signal is close to the phase of the second audio signal. In this case, the difference between the phases of the first and second audio signals at the frequency crossover point can be in the range of 150° to 210° to achieve a "superposition" of the bone conduction and air conduction sound waves and thus produce an effect of in-phase amplification. The difference between the phases of the first and second audio signals can be, for example, 210°, 200°, 190°, 180°, 170°, 160°, 150°, etc.

[0105] It is self-evident that the frequency values ​​of the frequency cutoff point, the first and second resonant frequencies, which are affected in the various embodiments described in this document, can be applied individually or in combination, depending on the intended purpose and scenario, provided this does not contradict the principles. All embodiments suitable for individual and combined application fall within the scope of protection disclosed by this document. Since bone conduction sound waves exhibit a significant phase shift before reaching the first resonant frequency and / or air conduction sound waves exhibit a significant phase shift before reaching the second resonant frequency, the frequency cutoff point can, for example, be higher than the first or second resonant frequency, i.e., it can be higher than the higher of the first and second resonant frequencies.This allows the phases of the bone conduction and air conduction sound waves to remain relatively stable when the frequency cutoff point is in the low frequency band (e.g., between 300 Hz and 1000 Hz). This ensures improved acoustic output performance of the acoustic output device in this low frequency band. Furthermore, since the first high-frequency resonant frequency of the bone conduction vibrator is higher than the first high-frequency resonant frequency (i.e., the third resonant frequency) of the air conduction vibrator, and the air conduction sound waves exhibit a significant phase shift after reaching the third resonant frequency, the frequency cutoff point can be lower than the third resonant frequency. This allows the phases of the bone conduction and air conduction sound waves to remain relatively stable when the frequency cutoff point is in the high frequency band (e.g., between 2500 Hz and 5000 Hz).This ensures improved acoustic output from the acoustic output device in this high-frequency band. Since the phase of bone conduction sound waves is stable between the first resonant frequency and its first high-frequency resonant frequency, and the phase of air conduction sound waves is stable between the second and third resonant frequencies, and since the first high-frequency resonant frequency of the bone conduction vibrating element is higher than the third resonant frequency of the air conduction vibrating element, the frequency cutoff point can therefore be set, for example, in the frequency range between the second resonant frequency or between the first and third resonant frequencies. This allows the phases of the bone conduction and air conduction sound waves to remain relatively stable when the frequency cutoff point lies within the frequency band sensitive to the human ear (e.g., between 300 Hz and 3500 Hz).This ensures improved acoustic output performance of the acoustic output device in this frequency band, which is sensitive to the human ear.

[0106] The basic concepts have already been described. Obviously, the detailed disclosure given above is merely an example for those skilled in the field and does not constitute a limitation of the present description. Although not explicitly stated here, those skilled in the field may make various modifications, improvements, and changes to the present description. Such modifications, improvements, and changes are suggested in the present description so that they are intended to be within the spirit and scope of the exemplary embodiments given here. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 202311427342.7

[0001]

Claims

[1] Acoustic output device, comprising: a case; a bone conduction vibration element configured to generate bone conduction sound waves so that the bone conduction sound waves are transmitted through the housing to the cochlea to produce sound; an air conduction vibration element configured to generate air conduction sound waves so that the air conduction sound waves are transmitted to the ear through a sound conduction opening provided in the housing; and a signal processing module configured to provide a first audio signal to the bone conduction vibration element and a second audio signal to the air conduction vibration element, wherein the first audio signal and the second audio signal have a frequency cut-off point, and the first audio signal and the second audio signal each comprise a corresponding component with frequencies above the frequency cut-off point and a corresponding component with frequencies below the frequency cut-off point, where the bone conduction vibration element exhibits a first resonance peak at a first resonance frequency, wherein the first resonance peak is the resonance peak of the bone conduction vibration element with the lowest resonance frequency in the frequency range, the air conduction vibration element exhibits a second resonance peak at a second resonance frequency, wherein the second resonance peak is the resonance peak of the air conduction vibration element with the lowest resonance frequency in the frequency domain, and the frequency cutoff point is higher than the first resonant frequency and the frequency cutoff point is higher than the second resonant frequency. [2] Acoustic output device according to claim 1, wherein the first resonant frequency lies between the second resonant frequency and the frequency cut-off point. [3] Acoustic output device according to claim 1 or 2, wherein the difference between the first resonant frequency and the frequency cut-off point and the difference between the second resonant frequency and the frequency cut-off point are each not less than 100 Hz. [4] Acoustic output device according to any one of claims 1 to 3, wherein the difference between the phases of the first audio signal and the second audio signal at the frequency crossover point does not exceed 30°. [5] Acoustic output device according to any one of claims 1 to 4, wherein the frequency crossover point is not lower than 1500 Hz. [6] Acoustic output device according to any one of claims 1 to 5, wherein the air conduction vibration element has a third resonance peak with a third resonance frequency, wherein the frequency cut-off point is lower than the third resonance frequency. [7] Acoustic output device according to claim 6, wherein the housing has two sound guide openings for directing the air conduction sound waves, wherein the sounds emitted through the two sound guide openings have an amplitude difference of less than 6 dB and a phase difference of 150° to 210°. [8] Acoustic output device according to claim 7, the housing is equipped with two separate receiving chambers, wherein the bone conduction vibration element is arranged in one of the recording chambers, and the air conduction vibration element is arranged in the other of the recording chambers, wherein the air conduction vibration element comprises a membrane, wherein the receiving chamber, in which the air conduction vibration element is arranged, is divided by the membrane into a rear chamber and a front chamber, the lower of the resonance frequencies of the front chamber and the rear chamber is defined as the third resonance frequency, and the difference between the third resonant frequency and the frequency cutoff point is not less than 500 Hz. [9] Acoustic output device according to claim 8, wherein the two sound guide openings are a first sound guide opening and a second sound guide opening, wherein the first sound guide opening connects the rear chamber to the outside environment, and the second sound guide opening connects the front chamber to the outside environment, wherein the sound emitted by the two sound guide openings has a far-field sound pressure level difference of not less than 3 dB in at least one pair of opposite directions. [10] Acoustic output device according to claim 8, wherein a partition wall arranged on the housing, the rear chamber is located on a side of the membrane facing away from the partition, and The anterior chamber is located between the membrane and the partition. [11] Acoustic output device according to claim 8, wherein the air conduction vibration element comprises a magnet arrangement located in the rear chamber. [12] Acoustic output device according to claim 6, wherein the difference between the third resonant frequency and the frequency cut-off point is not less than 500 Hz. [13] Acoustic output device according to any one of claims 1 to 12, wherein the frequency crossover point is not higher than 3000 Hz. [14] Acoustic output device according to any one of claims 7 to 13, wherein the difference between the acoustic loads of the two sound guide openings is less than 0.

15. [15] Acoustic output device according to any one of claims 1 to 14, wherein the signal processing module processes electrical signals containing acoustic information by high-pass filtering or low-pass filtering to obtain the first audio signal or the second audio signal accordingly.

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