An open earphone

Abstract

This specification provides an embodiment of an open-back headphone, comprising: a housing; a support structure configured to place the housing near the user's ear without obstructing the ear canal when worn; an upper microphone assembly receiving external sound through an upper sound-receiving hole, wherein the upper side of the housing has an upper protrusion, and the upper sound-receiving hole is disposed on the upper protrusion; a processing circuit configured to generate a noise-reducing signal based on the external sound collected by the upper microphone assembly; and a speaker located within the housing, configured to generate noise-reduced sound under the drive of the noise-reducing signal.

Description

[0001] Cross-references

[0002] This specification claims priority to Chinese application No. 202411452809.8, filed on October 16, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This manual relates to the field of acoustics, and in particular to an open-back headphone. Background Technology

[0004] As people's living standards continue to improve, headphones have become an indispensable item. Depending on user needs, headphones are categorized into various types, such as in-ear headphones and open-back headphones. Some types of open-back headphones hang on the user's ear, with the sound output located outside the ear canal, so they do not cause ear discomfort even after prolonged wear. However, because open-back headphones do not block the ear canal, ambient noise can easily enter, causing the user to hear both ambient noise and the sound emitted by the headphones simultaneously, affecting the listening experience.

[0005] Therefore, there is a need to provide an open-back headphone that reduces ambient noise to ensure a good listening experience. Utility Model Content

[0006] One embodiment of this specification provides an open-back headphone, comprising: a housing; a support structure configured to place the housing near a user's ear without obstructing the ear canal when worn; a microphone assembly configured to receive external sound; a processing circuit configured to generate a first noise-canceling signal based on the external sound collected by the microphone assembly; and a speaker located within the housing, configured to generate noise-canceling sound under the drive of the first noise-canceling signal, wherein the speaker includes a magnetic circuit assembly and two diaphragms located on both sides of the magnetic circuit assembly, the two diaphragms being configured to vibrate synchronously in the same direction.

[0007] One embodiment of this specification provides an open-back headphone, comprising: a housing; a support structure configured to place the housing near a user's ear without obstructing the ear canal when worn; a front microphone assembly receiving external sound through a front sound-receiving hole, wherein the housing includes a body and a connecting portion configured to connect the body and the support structure, and the front microphone assembly is disposed on the connecting portion; a processing circuit configured to generate a noise-canceling signal based on the external sound collected by the front microphone assembly; and a speaker located within the housing, configured to generate noise-canceling sound under the drive of the noise-canceling signal.

[0008] One embodiment of this specification provides an open-back headphone, comprising: a housing; a support structure configured to place the housing near a user's ear without obstructing the ear canal when worn; an upper microphone assembly receiving external sound through an upper sound-receiving hole, wherein the upper side of the housing has an upper protrusion, and a second sound-receiving hole is disposed on the upper protrusion; a processing circuit configured to generate a noise-reducing signal based on the external sound collected by the upper microphone assembly; and a speaker located within the housing, configured to generate noise-reduced sound under the drive of the noise-reducing signal.

[0009] One embodiment of this specification provides an open-back headphone, comprising: a housing; a support structure configured to place the housing near a user's ear without obstructing the ear canal when worn; a rear microphone assembly receiving external sound through a rear sound-receiving hole, wherein the inner side of the housing has a rear protrusion, and the rear sound-receiving hole is disposed on the rear protrusion; a processing circuit configured to generate a noise-canceling signal based on the external sound collected by the rear microphone assembly; and a speaker located within the housing, configured to generate noise-canceling sound under the drive of the noise-canceling signal.

[0010] Additional features will be set forth in part in the description which follows, and will become apparent to those skilled in the art upon consulting the following description and the accompanying drawings, or may be learned by the generation or operation of examples. The features of the invention can be realized and obtained by practice or use of various aspects of the methods, tools, and combinations set forth in the following detailed examples. Attached Figure Description

[0011] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0012] Figure 1 This is an exemplary block diagram of an open-back headphone according to some embodiments of this specification;

[0013] Figure 2 These are schematic diagrams illustrating the wearing of open-back headphones according to some embodiments of this specification;

[0014] Figure 3 This is a schematic diagram of an open-back headphone according to some embodiments of this specification;

[0015] Figure 4 This is yet another schematic diagram of an open-back headphone as illustrated in some embodiments of this specification;

[0016] Figure 5This is a cross-sectional schematic diagram of an open-back headphone according to some embodiments of this specification;

[0017] Figure 6 These are schematic diagrams illustrating the wearing of open-back headphones according to some embodiments of this specification;

[0018] Figure 7 This is a schematic diagram of an open-back headphone according to some embodiments of this specification;

[0019] Figure 8 This is a schematic diagram showing a plurality of exemplary positions of the second microphone hole according to some embodiments of this specification;

[0020] Figure 9 The second microphone hole is located at... Figure 8 Frequency response curves of the sound collected at several exemplary locations are shown.

[0021] Figure 10 This is a schematic diagram of the structure of a first microphone assembly according to some embodiments of this specification;

[0022] Figure 11 This is a frequency response curve of wind noise collected by the first microphone when the structure is provided with and without grooves or acoustic barriers, according to some embodiments of this specification.

[0023] Figure 12 This is a schematic diagram of the structure of the second microphone assembly according to some embodiments of this specification;

[0024] Figure 13 This is a schematic diagram of the structure of a third microphone assembly according to some embodiments of this specification;

[0025] Figure 14 This is a schematic diagram of an open-back headphone according to some embodiments of this specification. Specific Implementation

[0026] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. It should be understood that these exemplary embodiments are given merely to enable those skilled in the art to better understand and implement the present invention, and are not intended to limit the scope of the present invention in any way. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0027] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. The term "based on" means "at least partially based on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment."

[0028] In the description of this specification, it should be understood that the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number or order of the indicated technical features. Therefore, features defined as "first," "second," "third," etc., may explicitly or implicitly include at least one of those features. In the description of this specification, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0030] This specification provides an open-back headphone, including a housing, a support structure, a first microphone assembly, a second microphone assembly, a processing circuit, and a speaker. The support structure is configured to place the housing near the user's ear without obstructing the ear canal during wearing. The first microphone assembly is configured to receive external sound through a first microphone hole; the second microphone assembly is configured to receive external sound through a second microphone hole, wherein the first and second microphone holes are located on different sidewalls of the housing. The description of microphone holes being located on the sidewall (or side surface) of the housing can refer to the microphone hole being located on the sidewall of the housing, or it can refer to the microphone hole being located on other structures (e.g., protrusions) on the sidewall of the housing. The processing circuit is configured to determine a target noise reduction strategy from a plurality of noise reduction strategies and generate a first noise reduction signal according to the target noise reduction strategy, wherein the plurality of noise reduction strategies includes at least two of the following strategies: using the external sound collected by the first microphone assembly as ambient noise; using the external sound collected by the second microphone assembly as ambient noise; and generating ambient noise by combining the external sounds collected by the first and second microphone assemblies respectively. The speaker, located within the housing, is configured to generate noise-canceling sound under the drive of the first noise-canceling signal. Embodiments of this specification can determine a target noise-canceling strategy from multiple noise-canceling strategies based on external sound collected by multiple microphone components (e.g., a first microphone component, a second microphone component, etc.) located at different positions on the housing, thereby improving the accuracy of noise-canceling processing in open-back headphones.

[0031] Figure 1 This is an exemplary block diagram of an open-back headphone according to some embodiments of this specification; Figure 2 These are schematic diagrams illustrating the wearing of open-back headphones according to some embodiments of this specification; Figure 3 This is a schematic diagram of an open-back headphone according to some embodiments of this specification; Figure 4 This is yet another schematic diagram of an open-back headphone as illustrated in some embodiments of this specification.

[0032] The open-back headphones 100 can be used to acquire and / or play sound. In a wearing state (e.g., as...) Figure 2As shown in the wearing state, the open-back headset 100 (e.g., housing 110) can be worn near the user's ear without blocking the ear canal. Due to its open-back nature, ambient noise can easily enter the ear canal, causing the user to hear both ambient noise and the sound emitted by the open-back headset simultaneously, affecting the listening experience. In some embodiments, the open-back headset 100 may be configured with a microphone assembly for acquiring ambient noise and a speaker for converting electrical signals into sound. Based on the external sound acquired by the microphone assembly, the speaker of the open-back headset 100 can generate and play noise-canceling sounds to cancel out ambient noise, thereby reducing the impact of ambient noise. In some embodiments, to improve the call quality of the open-back headset 100, the open-back headset 100 may also utilize the aforementioned microphone assembly, or additionally configure other microphone assemblies, to pick up sound from a specific direction and / or a specific target range, such as the user's voice.

[0033] Combination Figures 1-4 The open-back headphone 100 may include a housing 110, a support structure 120, a microphone assembly 200 (e.g., a first microphone assembly 130, a second microphone assembly 140, a third microphone assembly 170, etc.), a processing circuit 150, and a speaker 160.

[0034] The housing 110 is used to carry one or more components of the open-back headphone 100. In some embodiments, a receiving cavity may be formed inside the housing 110 for accommodating one or more components of the open-back headphone 100, such as a first microphone assembly 130, a second microphone assembly 140, processing circuitry 150, a speaker 160, etc. In some embodiments, one or more components of the open-back headphone 100 may be carried on the housing.

[0035] The housing 110 can be, for example, a regular or irregular shape such as an annular, elliptical, racetrack-shaped, polygonal, U-shaped, V-shaped, or semi-circular. In some embodiments, such as Figure 3As shown, the housing 110 may have a major axis direction Y, a minor axis direction X, and a thickness direction Z that are orthogonal to each other. The major axis direction Y can be defined as the direction with a larger extension dimension in the shape of the two-dimensional projection surface of the housing 110 (e.g., the projection of the housing 110 onto the plane containing its inner surface when worn, or its projection onto the user's sagittal plane). (For example, when the projected shape of the housing 110 is rectangular or approximately rectangular, the major axis direction Y can also be called the length direction of the housing 110). For ease of explanation, this specification will use the projection of the housing 110 onto the sagittal plane when the open-back headphones 100 are worn on the human body as an example. The minor axis direction X can be defined as the direction perpendicular to the major axis direction Y in the shape of the projection of the housing 110 onto the sagittal plane (e.g., when the projected shape of the housing 110 is rectangular or approximately rectangular, the minor axis direction X can also be called the height direction of the housing 110). The thickness direction Z can be defined as a direction perpendicular to the sagittal plane, for example, consistent with the direction of the coronal axis, pointing towards the left and right sides of the user's body.

[0036] It should be noted that in medicine, anatomy, and other fields, the human body can be defined by three basic planes: the sagittal plane, the coronal plane, and the horizontal plane, as well as three basic axes: the sagittal axis, the coronal axis, and the vertical axis. The sagittal plane is a section perpendicular to the ground along the anteroposterior direction of the body (e.g., from the chest to the back), dividing the body into left and right parts. The coronal plane is a section perpendicular to the ground along the lateral direction of the body (e.g., from the left shoulder to the right shoulder), dividing the body into anterior and posterior parts. The horizontal plane is a section parallel to the ground along the vertical direction of the body (e.g., from the top of the head to the soles of the feet), dividing the body into superior and inferior parts. Correspondingly, the sagittal axis is the axis along the anteroposterior direction of the body and perpendicular to the coronal plane; the coronal axis is the axis along the lateral direction of the body and perpendicular to the sagittal plane; and the vertical axis is the axis along the vertical direction of the body and perpendicular to the horizontal plane.

[0037] For ease of explanation, this specification defines different sides of the housing 110, including the inner side, outer side, upper side, lower side, front side, and rear side. The inner side (e.g., Figure 4 The inner side (IS) shown is the side of the housing 110 facing the user's ear when worn; the outer side (e.g., Figure 2 as well as Figure 3 The outer side (OS) shown is the side of the housing 110 away from the user's ear when worn; the upper side (e.g., Figure 2 as well as Figure 3The upper side (US) shown is the side closest to the user's head along the short axis X of the housing 110 when worn; the lower side (e.g., Figure 2 as well as Figure 4 The lower side (LS) shown is the side of the open-back headphone 100 away from the top of the user's head along the short axis X of the housing when it is worn; the front side (FS) (for example, Figure 2 as well as Figure 4 The front side (FS) shown is the side facing away from the back of the ear along the long axis Y when worn; the back side (BS) (for example, Figure 2 as well as Figure 4 The rear side (BS) shown is the side facing behind the ear along the long axis Y when worn. The following descriptions in this specification are based on the structure of the housing 110.

[0038] like Figure 2 As shown, the housing 110 may include a body 111 and a connecting portion 112, the connecting portion 112 being used to connect the body 111 and the support structure 120. Exemplarily, the body 111 may be used to support the speaker assembly of the open-back headphone 100, and the connecting portion may be used to support the circuit board assembly of the open-back headphone 100. In some embodiments, the body 111 and the connecting portion 112 may be an integrally formed structure. In some embodiments, the body 111 and the connecting portion 112 may be a spliced ​​structure. For ease of explanation, the sides of the body 111 and the connecting portion 112 located on the same side may be collectively referred to as the sides of the housing 110. For example, the inner side IS of the housing 110 may refer to the inner side of the body 111 and / or the inner side of the connecting portion 112. As another example, the outer side OS of the housing 110 may refer to the outer side of the body 111 and / or the outer side of the connecting portion 112. In some embodiments, the body 111 and the connecting portion 112 may have different shapes; in this case, the sides of the connecting portion 112 may be divided with the side of the body 111 as the primary reference. As an example only, the main body 111 can be a cuboid, and the connecting part 112 can be a cylinder. The side surface of the connecting part 112 (e.g., the curved surface of the cylinder) can be divided into four parts corresponding to the cuboid, and each part corresponds to one side surface of the main body (i.e., the inner side surface, the outer side surface, the upper side surface, and the lower side surface).

[0039] The support structure 120 is used to position the shell 110 near the user's ear without obstructing the ear canal when worn. Figure 2 As shown, when worn, the support structure 120 is located on the ear and supports the shell 110. The support structure 120 can place the shell 110 near the ear canal without blocking the ear canal opening.

[0040] In some embodiments, the open-back headphone 100 may be an ear-hook type headphone. For example... Figure 2As shown, the support structure 120 can be an arc-shaped structure adapted to the user's ear, so that the open-back headphones 100 can be suspended on the user's ear. In the wearing state, the support structure 120 is located on the back side of the ear (i.e., the side of the auricle facing the head), and one end of the support structure 120 extends to the front side of the ear (i.e., the side of the auricle away from the head) and is connected to the connecting part 112 of the housing 110.

[0041] In some embodiments, the open-back headphones 100 can also be clip-on headphones. Correspondingly, the open-back headphones 100 can also include an abutment portion that rests against the back of the user's ear. For example, the abutment portion can rest against the back of the user's concha. The abutment portion can be a sphere, cylinder, cube, cuboid, or other shape. The support structure 120 can connect the abutment portion and the housing 110. In the wearing state, the support structure 120 can bypass the user's antihelix and auricle, so that the housing 110 is located in the user's concha and contacts the concha wall, and the abutment portion rests against the back of the user's ear. The housing 110, the abutment portion, and the support structure 120 cooperate to clamp the user's auricle and antihelix, thereby completing the wearing of the open-back headphones 100.

[0042] In some embodiments, to improve the stability of the open-back headphones 100 during wear, the open-back headphones 100 may employ any one or a combination of the following methods: First, at least a portion of the support structure 120 is configured as a conformal structure that conforms to at least one of the back of the ear and the head, thereby increasing the contact area between the support structure 120 and the ear and / or the head, thus increasing the resistance to the open-back headphones 100 falling off the ear. Second, at least a portion of the support structure 120 is configured as an elastic structure, allowing it to have a certain deformation during wear, thereby increasing the positive pressure of the support structure 120 on the ear and / or the head, thus increasing the resistance to the open-back headphones 100 falling off the ear. Third, at least a portion of the support structure 120 is configured to rest against the head during wear, creating a reaction force that holds the ear, causing the shell 110 to press against the front of the ear, thereby increasing the resistance to the open-back headphones 100 falling off the ear. Fourth, the shell 110 and the support structure 120 are configured to clamp the physiological parts such as the antihelix and conchae from the front and back sides of the ear when worn, thereby increasing the resistance to the open-back headphones 100 falling off the ear. Fifth, the shell 110 or the auxiliary structure connected to it is configured to at least partially extend into the physiological parts of the user's conchae, cymba conchae, triangular fossa, and scaphoid fossa, thereby increasing the resistance to the open-back headphones 100 falling off the ear.

[0043] In some embodiments, the open-back headphone 100 may include a battery, and the support structure 120 may also be used to house the battery.

[0044] In some embodiments, the microphone assembly 200 may include a first microphone assembly 130. The first microphone assembly 130 is used to collect external sound. In some embodiments, at least a portion of the first microphone assembly 130 may be disposed inside the housing 110. For example, the first microphone assembly 130 may be disposed within a receiving cavity of the housing 110 and receive external sound through a first sound-receiving hole 131. As another example, a portion of the first microphone assembly 130 may be disposed within the receiving cavity of the housing 110, while another portion may protrude from the surface of the housing. In some embodiments, the first microphone assembly 130 may be disposed outside the housing 110. For example, the first microphone assembly 130 may also be disposed on the surface of the housing 110. In some embodiments, the first microphone assembly 130 may also be disposed in other structures of the open-back headphone 100, such as in or on the surface of the support structure 120.

[0045] In some embodiments, the first microphone assembly 130 can be used to collect external ambient noise. The open-back headphone 100 (e.g., processing circuitry 150) can generate a noise-canceling signal based on the electrical signal generated by the first microphone assembly 130, and thereby drive the speaker 160 to output a noise-canceling sound that can cancel out the ambient noise.

[0046] To ensure that the ambient noise collected by the first microphone assembly 130 is closer to the noise in the user's surrounding environment (i.e., the ambient noise entering the user's ear canal), and to reduce the obstruction of the first sound-receiving hole 131 by the auricle, support structure 120, and housing 110 during wear, in some embodiments, the first sound-receiving hole 131 may be located on one of the front side, outer side, and lower side of the housing 110. For example, Figure 3 The first microphone hole 131 shown is located on the outer surface OS of the housing 110. In some embodiments, in order to avoid the first microphone assembly 130 from being interfered with by the sound generated by the open-back headphones 100, the first microphone hole 131 may be located near the acoustic null point of the open-back headphones 100.

[0047] In some embodiments, the first microphone assembly 130 can also be used to capture the user's speech. In this case, the first microphone assembly 130 can cooperate with one or more other microphone assemblies to form a microphone array pointing towards the user's mouth, thereby primarily capturing the sound from the user's mouth.

[0048] For more information on the first microphone assembly 130 and / or the first microphone port 131, please refer to [link / reference]. Figures 6-10 The details and related descriptions will not be repeated here.

[0049] In some embodiments, the microphone assembly 200 may include a second microphone assembly 140. The second microphone assembly 140 is used to collect external sound. In some embodiments, at least a portion of the second microphone assembly 140 may be disposed inside the housing 110. For example, the second microphone assembly 140 may be disposed within the receiving cavity of the housing 110 and receive external sound through a second sound receiving hole 141. As another example, a portion of the second microphone assembly 140 may be disposed within the receiving cavity of the housing 110, while another portion may protrude from the surface of the housing. The second microphone assembly 140 may be disposed outside the housing 110. For example, the second microphone assembly 140 may also be disposed on the surface of the housing 110. In some embodiments, the second microphone assembly 140 may also be disposed in other structures of the open-back headphone 100; for example, the second microphone assembly 140 may also be disposed in the support structure 120 or on the surface of the support structure 120. The second microphone assembly 140 may be disposed on the same structure as the first microphone assembly 130; for example, both the second microphone assembly 140 and the first microphone assembly 130 may be disposed within the receiving cavity. The second microphone assembly 140 can also be disposed on a different structure from the first microphone assembly 130. For example, the second microphone assembly 140 can be disposed in the accommodating cavity, while the first microphone assembly 130 can be disposed in the support structure 120.

[0050] In some embodiments, the second microphone assembly 140 can be used to collect external ambient noise. The open-back headphones 100 (e.g., processing circuitry 150) can generate a noise-canceling signal based on the electrical signal generated by the second microphone assembly 140, and thereby drive the speaker 160 to output noise-canceling sound that can cancel out the ambient noise. In some embodiments, the second microphone hole 141 can be disposed on the upper side US. By disposing the second microphone hole 141 on the upper side, the auricle, support structure 120, and housing 110 can partially block the second microphone hole 141 when worn, reducing the impact of airflow along the sagittal axis from the front to the back of the user's body on the second microphone hole 141, and effectively reducing wind noise in the external sound collected by the second microphone hole 141. Since the presence of wind noise can interfere with the noise cancellation effect of the open-back headphones 100, the ambient noise picked up by the second microphone assembly 140 can improve the effect of active noise cancellation in environments with wind noise.

[0051] In some embodiments, to prevent the second microphone assembly 140 from picking up sound generated by the open-back headphones 100 and thus interfering with its acquisition of ambient noise, the second microphone hole 141 may be located near the acoustic null point of the open-back headphones 100. More information about the second microphone assembly 140 and / or the second microphone hole 141 can be found in [link to relevant documentation]. Figures 6-9 as well as Figure 11 Its description will not be repeated here.

[0052] In some embodiments, the second microphone assembly 140 may cooperate with one or more other microphones to form a microphone array directed towards the user's mouth. For example, as Figure 2 As shown, in the wearing state, the second sound-receiving hole 141 connects with the first sound-receiving hole 131 to form a vector L, which points towards the user's mouth, so that the microphone array composed of the first microphone assembly 130 and the second microphone assembly 140 can mainly collect the sound from the user's mouth.

[0053] Some embodiments of this specification, by arranging the first microphone assembly 130 and the second microphone assembly 140 at different positions on the open-back headset 100, utilize the different effects of the two microphone assemblies in picking up ambient sound. This allows the open-back headset 100 to effectively identify the ambient noise to be reduced in different noise environments, thereby improving the noise reduction effect of the open-back headset 100 and providing users with a better listening experience. Additionally, by setting the positions of the first and second microphone holes 131 corresponding to the first microphone assembly 130 and the second microphone assembly 140, a microphone array pointing towards the user's mouth can be constructed. When the user uses the open-back headset 100 for a call, the microphone array can better capture the sound emitted by the user's mouth, thereby improving call quality. More details on using the first microphone assembly 130 and the second microphone assembly 140 for noise reduction and / or capturing the sound of the user's mouth can be found in [reference needed]. Figure 6 And its description.

[0054] The processing circuit 150 can process data and / or information obtained from one or more components of the open-back headphones 100 (e.g., the first microphone assembly 130, the second microphone assembly 140, the speaker 160, etc.) or other devices to achieve the required functions of the open-back headphones 100. For example, the processing circuit 150 can obtain data and / or information from a user's terminal device and control the function of the speaker 160 based on the data and / or information. As another example, the processing circuit 150 can acquire external sound collected by microphone assemblies (e.g., any one or more of the first microphone assembly 130, the second microphone assembly 140, the third microphone assembly 170, etc.) and generate a noise reduction signal based on the external sound, thereby achieving active noise cancellation.

[0055] In some embodiments, the open-back headphones 100 may include a first microphone assembly 130 and a second microphone assembly 140. The second microphone assembly 140 functions the same as or similar to the first microphone assembly 130, with one difference: in everyday use, since the second sound hole 141 can be located on the upper side US, the second microphone assembly 140 captures less wind noise in the sound compared to the first microphone assembly 130.

[0056] Based on the differences in ambient noise collected by the first microphone assembly 130 and the second microphone assembly 140, some embodiments of this specification can select at least one of the first microphone assembly 130 and the second microphone assembly 140 as a feedforward microphone to collect ambient noise for noise reduction processing, depending on the scenario, thereby ensuring the active noise reduction effect of the open-back headphones 100 in different scenarios. For example, the processing circuit 150 can determine a target noise reduction strategy from multiple noise reduction strategies and generate a noise reduction signal (or a first noise reduction signal) according to the target noise reduction strategy. The speaker 160 can generate noise-reduced sound under the drive of the noise reduction signal. The noise-reduced sound can have the same amplitude and opposite phase as the noise at the user's ear canal, thereby eliminating the noise at the user's ear canal. The multiple noise reduction strategies include at least two of the following strategies: using the external sound collected by the first microphone assembly 130 as ambient noise; using the external sound collected by the second microphone assembly 140 as ambient noise; and combining the external sounds collected by the first microphone assembly 130 and the second microphone assembly 140 respectively to generate ambient noise.

[0057] In some embodiments, the processing circuit 150 can determine a target noise reduction strategy from multiple noise reduction strategies based on trigger information, thereby determining a feedforward microphone from the first microphone assembly 130 and the second microphone assembly 140. The trigger information can be used to specify the electrical signals generated by the first microphone assembly 130 and / or the second microphone assembly 140 as the basis for subsequent noise reduction, correspondingly reflecting the microphone as a feedforward microphone. For example, the processing circuit 150 can determine both the first microphone assembly 130 and the second microphone assembly 140 as feedforward microphones based on the trigger information, meaning both the first microphone assembly 130 and the second microphone assembly 140 collect ambient noise. The processing circuit 150 can combine the external sounds collected by the first microphone assembly 130 and the second microphone assembly 140 respectively to generate ambient noise, thereby generating a first noise reduction signal. As another example, the processing circuit 150 can also determine the first microphone assembly 130 as a feedforward microphone based on the trigger information, meaning the processing circuit 150 can use the external sounds collected by the first microphone assembly 130 as ambient noise, thereby generating a first noise reduction signal based on the ambient noise collected by the first microphone assembly 130. For example, the processing circuit 150 can also determine the second microphone component 140 as a feedforward microphone based on the trigger information. That is, the processing circuit 150 can use the external sound collected by the second microphone component 140 as ambient noise, and thus generate a first noise reduction signal based on the ambient noise collected by the second microphone component 140.

[0058] In some embodiments, the trigger information can be determined by a user (e.g., a user or other object capable of manipulating the open-back headset 100). For example, a trigger button may be provided on the housing 110, which the user can control. The processing circuit 150 can determine the trigger information based on the trigger button, thereby identifying the feedforward microphone from the first microphone assembly 130 and the second microphone assembly 140. As another example, the user can also send trigger information through a user terminal (e.g., a mobile phone, computer, etc.) communicatively connected to the open-back headset 100. The processing circuit 150 can receive the trigger information, thereby identifying the feedforward microphone from the first microphone assembly 130 and the second microphone assembly 140.

[0059] In some embodiments, the processing circuit 150 may also acquire and analyze external sounds collected by the first microphone assembly 130 and the second microphone assembly 140, thereby determining a target noise reduction strategy from a variety of noise reduction strategies.

[0060] In some embodiments, in response to the wind noise in the external sound collected by the first microphone assembly 130 or the second microphone assembly 140 satisfying a first condition, the processing circuit 150 may treat the external sound collected by the first microphone assembly as ambient noise; or in response to the wind noise in the external sound collected by the first microphone assembly 130 or the second microphone assembly 140 satisfying a second condition, the processing circuit 150 may treat the external sound collected by the second microphone assembly 140 as ambient noise. The first condition may refer to a low level of wind noise in the external sound collected by the first microphone assembly 130, and the second condition may refer to a high level of wind noise in the external sound collected by the first microphone assembly 130.

[0061] For example, when the first microphone assembly 130 and the second microphone assembly 140 collect external sounds, the difference in the sounds they collect mainly comes from wind noise, which is reflected in the difference in the intensity and proportion of low-frequency components in the generated electrical signals. Therefore, the processing circuit 150 can analyze and process the external sounds collected by the first microphone assembly 130 and the second microphone assembly 140 (e.g., compare the differences in their spectrograms) to determine the sound differences. When the sound difference is less than or equal to a preset difference threshold (e.g., the difference in low-frequency components in the sounds collected by the first microphone assembly 130 and the second microphone assembly 140 is less than the preset difference threshold), it indicates that the wind noise in the external sounds collected by the first microphone assembly 130 is relatively small, and the processing circuit 150 can treat the external sounds collected by the first microphone assembly 130 as ambient noise. When the sound difference is greater than the preset difference threshold, it indicates that the wind noise in the external sounds collected by the first microphone assembly 130 is relatively large, and the processing circuit 150 can treat the external sounds collected by the second microphone assembly 140 as ambient noise and perform noise reduction processing based on the ambient noise collected by the second microphone assembly 140.

[0062] In some embodiments, the processing circuit 150 may further input the external sound collected by the first microphone component 130 and / or the external sound collected by the second microphone component 140 into a machine learning model, thereby using the machine learning model to determine which microphone component's external sound should be considered as ambient noise. The output of the machine learning model may be a target noise reduction strategy. The aforementioned machine learning model may be a convolutional neural network model or any other machine learning model capable of implementing its functionality. The machine learning model can be trained using training samples, which may include first sample sounds collected by the first microphone component 130 and second sample sounds collected by the second microphone component 140. Training labels may include sample target noise reduction strategies. Training samples may be obtained manually; for example, when collecting a portion of the first sample sound, airflow may be generated to make some of the first sample sound have significant wind noise, and when collecting the second sample sound and a portion of the first sample sound, the airflow speed may be controlled to avoid generating wind noise. Training labels may be obtained manually. For example, when the first sample sound contains significant wind noise, the sample target noise reduction strategy may be to treat the external sound collected by the second microphone component 140 as ambient noise.

[0063] In some embodiments, the processing circuit 150 can also acquire and analyze the external sound collected by the first microphone assembly 130 to determine a target noise reduction strategy. For example, the processing circuit 150 can determine whether the sound pressure level in a preset frequency band range of the external sound collected by the first microphone assembly 130 is less than or equal to a preset sound pressure level threshold. The preset frequency band range can be a frequency band where wind noise often occurs. For example, the preset frequency band range can be 20Hz to 1000Hz. When the sound pressure level in the preset frequency band range of the external sound is less than or equal to the preset sound pressure level threshold, it indicates that the wind noise in the external sound collected by the first microphone assembly 130 is relatively small, satisfying the first condition. Therefore, the processing circuit 150 can treat the external sound collected by the first microphone assembly 130 as ambient noise. When the sound pressure level in the preset frequency band range of the external sound is greater than the preset sound pressure level threshold, it indicates that the wind noise in the external sound collected by the first microphone assembly 130 is relatively large, satisfying the second condition. Therefore, the processing circuit 150 can treat the external sound collected by the second microphone assembly 140 as ambient noise.

[0064] In some embodiments of this specification, the feedforward microphone can be determined from the first microphone assembly 130 and the second microphone assembly 140 through the aforementioned settings. When wind noise is relatively low in the collected ambient noise, the external sound collected by the first microphone assembly 130 can be selected as the ambient noise to ensure that the ambient noise during noise reduction processing is closer to the ambient noise heard by the user, thereby improving the noise reduction effect of the open-back headphones 100. When wind noise is relatively high in the collected ambient noise, the external sound collected by the second microphone assembly 140 can be selected as the ambient noise to reduce the adverse effects of wind noise in the ambient noise during noise reduction processing, thereby improving the accuracy of noise reduction processing of the open-back headphones 100. Furthermore, the processing circuit 150 can also automatically determine the target noise reduction strategy, thereby determining the feedforward microphone from the first microphone assembly 130 and the second microphone assembly 140, improving the user experience.

[0065] Based on the differences in ambient noise collected by the first microphone assembly 130 and the second microphone assembly 140, some embodiments of this specification can also combine the ambient noise collected by the first microphone assembly 130 and the second microphone assembly 140 for noise reduction processing. For example, in response to wind noise in the external sound collected by the first microphone assembly 130 or the second microphone assembly 140 satisfying a second condition, the processing circuit 150 combines the external sound collected by the first microphone assembly 130 and the second microphone assembly 140 respectively to generate ambient noise.

[0066] As mentioned earlier, wind noise is mainly concentrated in the low frequency range. Therefore, the low-frequency components of the ambient noise collected by the first microphone assembly 130 are more susceptible to wind noise. Thus, when the wind noise in the external sound collected by the first microphone assembly 130 or the second microphone assembly 140 meets the second condition (i.e., the wind noise is relatively high), the processing circuit 150 can extract the corresponding frequency components from the external sound collected by the first microphone assembly 130 and the second microphone assembly 140, and generate a noise reduction signal accordingly. As an example, the high-frequency components of the external sound collected by the first microphone assembly 130 that are less affected by wind noise and the low-frequency components of the external sound collected by the second microphone assembly 140 that are less affected by wind noise can be used in the subsequent noise reduction process. Specifically, the processing circuit 150 can acquire the ambient noise collected by the first microphone component 130 (for ease of explanation, the ambient noise collected by the first microphone component 130 can also be referred to as the first ambient noise), acquire the ambient noise collected by the second microphone component 140 (for ease of explanation, the ambient noise collected by the second microphone component 140 can also be referred to as the second ambient noise), and generate a target ambient noise based on the first ambient noise in the first frequency band and the second ambient noise in the second frequency band. The target ambient noise refers to the ambient noise that needs to be denoised. The second frequency band is higher than the first frequency band. The first and second frequency bands can be determined based on a preset. For example, the first frequency band can be 20–1000 Hz, and the second frequency band can be 1000–20000 Hz.

[0067] Since wind noise often occurs in low frequencies, the processing circuit 150 generates a target ambient noise by selecting a first ambient noise in a first frequency band and a second ambient noise in a second frequency band. Then, it generates a first noise reduction signal based on the target ambient noise. This can retain the frequency bands in the first ambient noise that do not contain wind noise, remove the frequency bands in the first ambient noise that contain wind noise, and compensate for the removed frequency bands in the first ambient noise based on the second ambient noise. This can reduce wind noise in the ambient noise during noise reduction processing and make the ambient noise during noise reduction processing as close as possible to the ambient noise heard by the user, thereby improving the noise reduction effect of the open-back headphones 100.

[0068] In some embodiments, the processing circuit 150 can directly combine the external sounds collected by the first microphone assembly 130 and the second microphone assembly 140 to generate ambient noise, without needing to determine whether the wind noise in the external sounds collected by the first microphone assembly 130 or the second microphone assembly 140 meets the second condition. For example, the processing circuit 150 can acquire the external sounds collected by the first microphone assembly 130 and the second microphone assembly 140, extract the first ambient noise in the first frequency band and the second ambient noise in the second frequency band, thereby generating the target ambient noise.

[0069] In some embodiments, the open-back headphones 100 may include, but are limited to, a first microphone assembly 130 and a second microphone assembly 140, and perform noise reduction processing on ambient noise collected by at least one of the first microphone assembly 130 and the second microphone assembly 140. This setting can generate inverted signals for noise reduction more quickly, reduce noise reduction delay, and improve the real-time performance of noise reduction.

[0070] In some embodiments, the microphone assembly 200 may include a third microphone assembly 170. The third microphone assembly 170 can be used to collect external sound. In some embodiments, at least a portion of the third microphone assembly 170 may be disposed inside the housing 110. For example, the third microphone assembly 170 may be disposed within the receiving cavity of the housing 110 and receive external sound through a third sound-receiving hole 171. As another example, a portion of the third microphone assembly 170 may be disposed within the receiving cavity of the housing 110, while another portion may protrude from the surface of the housing. In some embodiments, the third microphone assembly 170 may be disposed outside the housing 110. For example, the third microphone assembly 170 may also be disposed on the surface of the housing 110. In some embodiments, when the open-back headphones 100 simultaneously includes a first microphone assembly 130, a second microphone assembly 140, and a third microphone assembly 170, the first microphone assembly 130, the second microphone assembly 140, and the third microphone assembly 170 may be disposed on the same structure in the open-back headphones 100, or they may be disposed on different structures in the open-back headphones 100.

[0071] In some embodiments, the third microphone assembly 170 can be used to collect external ambient noise. The open-back headphone 100 (e.g., processing circuitry 150) can generate a noise-canceling signal based on the electrical signal generated by the third microphone assembly 170, and thereby drive the speaker 160 to output a noise-canceling sound capable of canceling out the ambient noise. In some embodiments, the third microphone assembly 170 can be used to collect noise in the user's ear canal, and the processing circuitry 150 can generate a noise-canceling signal based on the collected noise in the ear canal. The speaker 160 can generate a noise-canceling sound with the same amplitude but opposite phase to the noise in the ear canal based on the noise-canceling signal, thereby eliminating the noise in the user's ear canal. In some embodiments, the third microphone hole 171 can be located on the inner surface IS and close to the user's ear canal opening. This arrangement allows the sound collected by the third microphone assembly 170 to be closer to the sound in the user's ear canal, thereby improving the accuracy of noise reduction using the third microphone assembly 170.

[0072] In some embodiments, the third microphone assembly 170 can be used to capture user voice during a call.

[0073] For more information on the third microphone component 170, please refer to [link / reference]. Figure 13The details and related descriptions will not be repeated here.

[0074] In some embodiments, the open-back headset 100 may include, and only includes, a microphone assembly. The microphone assembly may be used to capture external sound for noise reduction processing and to capture the user's voice during a call. For example, the open-back headset 100 may include, and only includes, a first microphone assembly 130. As another example, the open-back headset 100 may include, and only includes, a second microphone assembly 140. Yet another example, the open-back headset 100 may include, and only includes, a third microphone assembly 170.

[0075] In some embodiments, the open-back headset 100 may include, and only include, two microphone assemblies.

[0076] For example, the open-back headset 100 may include, but is not limited to, a first microphone assembly 130 and a second microphone assembly 140. Both the first microphone assembly 130 and the second microphone assembly 140 can function as feedforward microphones to collect ambient noise. During noise reduction processing, the processing circuit 150 can select at least one of the first microphone assembly 130 and the second microphone assembly 140 as a feedforward microphone (i.e., determine the target noise reduction strategy from multiple noise reduction strategies) to generate a noise-reduced signal. Alternatively, by setting the positions of the first and second microphone holes 131 corresponding to the first and second microphone assemblies 130 and 140, a microphone array pointing towards the user's mouth can be constructed. When the user makes a call using the open-back headset 100, the microphone array can better capture the sound emitted from the user's mouth, thereby improving call quality.

[0077] For example, the open-back headphones 100 may include only a first microphone assembly 130 (or a second microphone assembly 140) and a third microphone assembly 170. The first microphone assembly 130 (or the second microphone assembly 140) may serve as a feedforward microphone, and the third microphone assembly 170 may serve as a feedback microphone for active noise cancellation. For example, the processing circuit 150 may use the external sound collected by the first microphone assembly 130 (or the second microphone assembly 140) as ambient noise to generate a first noise-canceling signal, and drive the speaker 160 to generate noise-canceling sound (or first noise-canceling sound) based on the first noise-canceling signal. The third microphone assembly 170 may collect a second noise-canceling sound. The second noise-canceling sound refers to the noise remaining after the noise-canceling sound generated by the speaker 160 based on the first noise-canceling signal is canceled out by the ambient noise at the ear canal. The processing circuit 150 may adjust the first noise-canceling signal according to the second noise-canceling sound. For example, the processing circuit 150 may adjust the magnitude and phase of the first noise-canceling signal according to the electrical signal generated by the third microphone assembly 170. The speaker 160 can generate adjusted noise-canceling sound under the drive of the adjusted first noise-canceling signal, thereby further eliminating residual noise in the user's ear canal.

[0078] In some embodiments, the open-back headphones 100 may include three microphone components. By way of example only, in some embodiments, the open-back headphones 100 may include a first microphone component 130, a second microphone component 140, and a third microphone component 170, and perform active noise cancellation using at least one of the aforementioned first microphone component 130, second microphone component 140, and third microphone component 170. For example, the open-back headphones 100 may collect ambient noise based on at least one of the first microphone 130 and second microphone 140, and may also collect a second noise-canceling sound (or residual noise) at the ear canal using the third microphone component 170. The processing circuit 150 may analyze and process the ambient noise using the second noise-canceling sound and generate a first noise-canceling signal. For example, the processing circuit 150 may process the noise based on the following formula:

[0079] e(t)=p(t)+y(t), (1)

[0080] Where y(t) is the first noise reduction signal, p(t) is the ambient noise, and e(t) is the second noise reduction sound at the ear canal. The processing circuit 150 can continuously update the first noise reduction signal based on the ambient noise and the second noise reduction sound, so that the second noise reduction sound collected by the third microphone component 170 is as small as possible, thereby improving the noise reduction effect of the open-back headphones 100.

[0081] In some embodiments, when the third microphone assembly 170 is used as a feedback microphone, in order to more accurately reflect the sound at the user's ear canal, the third microphone assembly 170, as a feedback microphone, can be located closer to the user's ear canal than the first microphone assembly 130 and / or the second microphone assembly 140, which are used as feedforward microphones. Therefore, in some embodiments, the third microphone hole 171 corresponding to the third microphone assembly 170 can be located on the inner side of the housing 110 and closer to the user's ear canal opening.

[0082] In some embodiments, when the open-back headset 100 may include three microphone components, at least one of the three microphone components may be used to capture user voice during a call. For example, during a call, the first microphone component 130, the second microphone component 140, and the third microphone component 170 may all be used to capture user voice. If wind noise is significant in the sound captured by the first microphone component 130 and / or the second microphone component 140, the processing circuit 150 may select one of the sounds picked up by the first microphone component 130, the second microphone component 140, and the third microphone component 170 as the user's voice. As an example only, the processing circuit 150 may compare the intensity and proportion of low-frequency components in the sounds picked up by the three microphone components to select the sound with the least wind noise as the user's voice. For another example, the processing circuit 150 may select the sound with the highest signal-to-noise ratio from the sounds picked up by the three microphone components as the user's voice. For yet another example, the processing circuit 150 may compare the speech quality in the sounds picked up by the three microphone components based on a speech activity detection algorithm to select the sound with the highest speech quality as the user's voice.

[0083] The speaker 160 can be used to convert electrical signals into sound. In some embodiments, the speaker 160 can be located within the housing 110 and used to generate noise-canceling sound under the drive of a first noise-canceling signal. The noise-canceling sound can perform noise reduction processing on the open-back headphones 100. In some embodiments, the speaker 160 can also output other audio, such as alert sounds, audio played according to user needs, etc.

[0084] The housing 110 may include one or more sound outlets, through which the speaker 160 outputs the generated sound signal to the outside of the housing 110. For example... Figure 3 as well as Figure 4As shown, a first sound outlet 1111 may be provided on the inner surface IS of the housing 110 to guide the sound generated at the front of the speaker 160 through the housing 110 and into the ear canal. A second sound outlet 1112 may be provided on other sidewalls of the housing 110 (e.g., on the outer surface OS) to balance the air pressure inside the housing 110 when the speaker 160 vibrates. The second sound outlet 1112 can also be used to guide the sound generated at the rear of the speaker 160 through the housing 110 to cancel out the sound (e.g., far-field sound) emanating from the first sound outlet 1111, thereby reducing sound leakage in the far field of the open-back headphones 100.

[0085] In some embodiments, the speaker 160 can be a single-diaphragm speaker. A first sound outlet 1111 can communicate with the front side of the diaphragm (i.e., the front side of the speaker 160), and a second sound outlet 1112 can communicate with the back side of the diaphragm. In some embodiments, the speaker 160 can also be a dual-diaphragm speaker. A dual-diaphragm speaker can include a magnetic circuit assembly, a voice coil, and a first diaphragm and a second diaphragm disposed on both sides of the magnetic circuit assembly. Through the action of the magnetic circuit assembly and the voice coil, the first diaphragm and the second diaphragm can be driven to vibrate respectively.

[0086] In some embodiments, the first diaphragm and the second diaphragm may be driven by different voice coils (e.g., the first diaphragm is driven by a first voice coil, and the second diaphragm is driven by a second voice coil) to drive the first diaphragm and the second diaphragm to vibrate asynchronously or synchronously. More information about dual-diaphragm loudspeakers can be found at [link to relevant documentation]. Figure 5 The details and related descriptions will not be repeated here.

[0087] Figure 5 This is a cross-sectional schematic diagram of an open-back headphone according to some embodiments of this specification.

[0088] For example only, speaker 160 can be a dual-voice-coil, dual-diaphragm speaker. For example... Figure 5 As shown, the dual-diaphragm loudspeaker 160 may include a first diaphragm 161, a second diaphragm 162, a magnetic circuit assembly 163, a first voice coil 164, and a second voice coil 165. The first diaphragm 161 and the second diaphragm 162 may be spaced apart on both sides of the magnetic circuit assembly 163 along the thickness direction Z of the housing 110 and about the center plane (e.g., Figure 7 or Figure 12The central plane A shown is symmetrical. The magnetic circuit assembly 163 may include a magnet 1631, a first magnetic plate 1632, and a second magnetic plate 1633. One end of the first voice coil 164 is located within the magnetic gap of the magnetic circuit assembly 163, and the other end of the first voice coil 164 is connected to the first diaphragm 161. One end of the second voice coil 165 is located within the magnetic gap of the magnetic circuit assembly 163, and the other end of the second voice coil 165 is connected to the second diaphragm 162. When the first voice coil 164 and / or the second voice coil 165 are energized, they can vibrate under the action of the magnetic field and drive the corresponding first diaphragm 161 and / or second diaphragm 162 to vibrate, thereby producing sound. The vibration direction of the first diaphragm 161 and / or the second diaphragm 162 may be parallel or approximately parallel to the thickness direction Z of the shell.

[0089] In some embodiments, such as Figure 5 As shown, the aforementioned dual-diaphragm loudspeaker may also include a connector 166 (for ease of explanation, the connector 166 may also be referred to as the first connector 166). The first connector 166 can connect the first voice coil 164 and the second voice coil 165, thereby enabling the first diaphragm 161 and the second diaphragm 162 to vibrate synchronously in a better manner.

[0090] In some embodiments, the aforementioned dual-diaphragm speaker may not include the first connector 166. The open-back headphone 100 may energize the first voice coil 164 and the second voice coil 165 respectively, thereby driving the first diaphragm 161 and the second diaphragm 162 to vibrate. In this case, the vibration of the first diaphragm 161 and the second diaphragm 162 may be in the same direction or in opposite directions.

[0091] In some embodiments, the first diaphragm 161 and the second diaphragm 162 may also be driven by the same voice coil, thereby causing the first diaphragm 161 and the second diaphragm 162 to vibrate synchronously and in the same direction. For example, the loudspeaker 160 can be a single-voice-coil dual-diaphragm loudspeaker. The aforementioned single-voice-coil dual-diaphragm loudspeaker may include a magnetic circuit assembly, a voice coil, a second connector, a first diaphragm, and a second diaphragm. The magnetic circuit assembly may include a magnetic plate and a magnet. The first diaphragm and the second diaphragm are respectively located on opposite sides of the magnetic circuit assembly. One end of the voice coil is located within the magnetic gap of the magnetic circuit assembly, and the other end of the voice coil is connected to the first diaphragm. When the voice coil is energized, it can vibrate under the action of the magnetic field and drive the corresponding first diaphragm to vibrate. In the vibration direction of the first diaphragm and the second diaphragm, the magnetic circuit assembly is provided with a through hole. The second diaphragm can be connected to the first diaphragm or the voice coil through the second connector, thereby vibrating under the drive of the first diaphragm or the voice coil.

[0092] The housing 110 may include one or more sound outlets, through which the speaker 160 outputs the generated sound signal to the outside of the housing 110. For example, combined with Figure 3 as well as Figure 4A first sound outlet 1111 may be provided on the inner surface IS of the housing 110 to guide the sound generated by the front side of the speaker 160 (i.e., the side of the first diaphragm 161 facing away from the second diaphragm 162) out of the housing 110 and into the ear canal. A second sound outlet 1112 may be provided on other sidewalls of the housing 110 (e.g., on the outer surface OS) to balance the air pressure inside the housing 110 when the speaker 160 vibrates. The second sound outlet 1112 can also be used to guide the sound generated by the rear side of the speaker 160 (i.e., the side of the second diaphragm 162 facing away from the first diaphragm 161) out of the housing 110 and cancel out the sound (e.g., far-field sound) emanating from the first sound outlet 1111. Exemplarily, the speaker 160 can emit sounds with a phase difference (e.g., opposite phase) through the first sound outlet 1111 and the second sound outlet 1112. These sounds with a phase difference can interfere with each other in the far field, creating a sound leakage reduction effect. The first sound outlet 1111 and / or the second sound outlet 1112 can be a single hole or a plurality of spaced-apart holes. For example, the holes can be formed by drilling directly on the surface of the housing 110, or they can refer to the holes in the acoustic steel mesh or acoustic yarn corresponding to the speaker 160.

[0093] Some embodiments of this specification, by employing a dual-diaphragm speaker, can improve the magnetic field utilization of the magnetic circuit assembly and the space utilization of the housing 110. Furthermore, the dual-diaphragm configuration significantly increases the effective contact area between the diaphragm and air, thereby increasing the amount of air that the diaphragm can push during vibration, enabling the open-back headphones 100 to provide a higher intensity output. In open-back scenarios, the ambient noise heard by the user is significantly greater than that heard when wearing in-ear headphones. By improving the output performance of the open-back headphones 100, it is possible to allow the open-back headphones 100 to output higher volume noise-canceling audio, thus ensuring the noise-canceling effect of the open-back headphones 100. In some embodiments, the two diaphragms of the dual-diaphragm speaker can vibrate synchronously in the same direction, enabling the open-back headphones 100 to provide a higher intensity output with lower distortion. Simultaneously, it makes the amplitude and phase frequency responses of the sound waves generated by the open-back headphones 100 more stable and less volatile, resulting in a flatter output over a wider frequency range, further enhancing the active noise cancellation effect over a wider frequency range.

[0094] In addition, with the configuration of a dual-diaphragm loudspeaker, it is easier to design the cavities corresponding to the two diaphragms. For example, it is easier to make the cavity structures corresponding to the first and second sound holes more consistent, so that the frequency response of the sound output from the first and second sound holes is more consistent, which is beneficial to improve the sound leakage reduction effect over a wider frequency range.

[0095] As described above, at least one of the first microphone assembly 130 and the second microphone assembly 140 can serve as a feedforward microphone to collect ambient noise. To ensure that the ambient noise collected by the first microphone assembly 130 is closer to the noise in the user's surroundings and to reduce the obstruction of the first sound-collecting hole 131 by the ear and the housing 110 during wear, the first sound-collecting hole 131 can be located on one of the front side, outer side, or lower side of the housing 110. For example, Figure 3 The first sound hole 131 shown is located on the outer side OS of the housing 110.

[0096] In some embodiments, when worn, the projection of the first microphone 131 onto the user's sagittal plane can be closer to the user's ear canal opening in the projection of the first microphone 131 and the second microphone 141. For example, the first microphone 131 can be located in the area directly above and near the user's ear canal opening to ensure that the ambient noise collected by the first microphone 130 is closer to the ambient noise heard by the user, thereby improving the noise reduction effect when performing noise reduction processing based on the ambient noise collected by the first microphone 130. Figure 2 As shown, the first microphone hole 131 is located on the outer side of the housing 110, in the area directly above the user's ear canal opening. Therefore, the ambient noise is close to the noise actually heard by the user. Furthermore, the position of the first microphone hole 131 is far from the auricle and the support structure 120, and will not be blocked by the auricle, the support structure 120, or the housing 110 itself. This prevents the sound collected by the first microphone 130 from being reflected by the auricle, the support structure 120, or the housing 110 and thus failing to accurately reflect the actual noise transmitted to the user's ear canal opening. This further ensures that the ambient noise collected by the first microphone 130 is close to the noise actually heard by the user.

[0097] In order to partially obstruct the second microphone hole 141 by the auricle and housing 110 when worn, thereby reducing the impact of airflow along the sagittal axis from the front to the back of the user's body on the second microphone hole 141, the second microphone hole 141 can be located on the upper side US. By placing the second microphone hole 141 on the upper side of housing 110, wind noise in the external sound collected by the second microphone hole 141 can be effectively reduced. On the other hand, by adjusting the position of the second microphone hole 141 on the upper side of housing 110, the vector L formed by the second microphone hole 141 and the first microphone hole 131 can be directed towards the user's mouth. This allows the signal from the user's mouth to be enhanced based on the time difference or phase difference between the arrival of the sound waves at the first microphone assembly 130 and the second microphone assembly 140, so that the microphone array composed of the first microphone assembly 130 and the second microphone assembly 140 can mainly collect the sound from the user's mouth.

[0098] The vector formed between the second microphone hole 141 and the first microphone hole 131 can refer to the vector formed by connecting the centroid of the second microphone hole 141 to the centroid of the first microphone hole 131. Figure 6 These are schematic diagrams illustrating the wearing of open-back headphones according to some embodiments of this specification. Figure 6 As shown, in the wearing state, the projection of the second sound-receiving hole 141 (e.g., the centroid of the second sound-receiving hole 141) onto the sagittal plane is connected by a line M (M can be understood as the projection of vector L onto the sagittal plane), and the projection of the second sound-receiving hole 141 onto the sagittal plane is connected by a line N to the projection of the user's mouth feature point P (e.g., the user's lip bead) onto the sagittal plane. In some embodiments, in order to improve the acquisition effect of the microphone array formed by the first microphone assembly 130 and the second microphone assembly 140 on the user's mouth sound, the included angle between the line M and the line N can be within a preset range. For example, in the direction towards the top of the user's head, the line M and the line N can have a first included angle α, which can be in the range of 0-70°. As another example, in the direction away from the top of the user's head, the line M and the line N can have a second included angle β, which can be in the range of 0-60°. By setting the range of the first and second included angles, vector L can be directed towards the user's mouth, constructing a microphone array that primarily captures sound from the user's mouth, thereby ensuring clear call quality. In some embodiments, to further improve the sound capture effect of the microphone array formed by the first microphone assembly 130 and the second microphone assembly 140 on the user's mouth sound, the first included angle α can be in the range of 0-50°, and the second included angle β can be in the range of 0-40°. In some embodiments, to further improve the sound capture effect of the microphone array formed by the first microphone assembly 130 and the second microphone assembly 140 on the user's mouth sound, the first included angle α can be in the range of 0-30°, and the second included angle β can be in the range of 0-20°.

[0099] In some embodiments, to ensure sufficient time or phase difference when sound waves reach the first microphone assembly 130 and the second microphone assembly 140, thereby enhancing the signal from the user's mouth based on this time or phase difference, and enabling the microphone array composed of the first microphone assembly 130 and the second microphone assembly 140 to primarily capture the sound from the user's mouth, the distance between the first sound-receiving hole 131 and the second sound-receiving hole 141 can be greater than 15 mm. For example, the distance between the first sound-receiving hole 131 and the second sound-receiving hole 141 can be greater than 20 mm. As another example, the distance between the first sound-receiving hole 131 and the second sound-receiving hole 141 can be greater than 30 mm. In this specification, unless otherwise specified, the distance between the two holes refers to the shortest distance between the centroids of the two holes on the surface of the housing.

[0100] Combination Figure 3 and Figure 4 The inner side of the housing 110 is provided with a first sound outlet 1111, and the outer side of the housing 110 is provided with a second sound outlet 1112. By placing the first sound outlet 1111 on the inner side facing the user's ear canal, the sound emitted by the first sound outlet 1111 can directly reach the user's ear canal opening, thereby improving the listening effect. The second sound outlet 1112 can be used to balance the air pressure inside the housing 110 when the speaker 160 vibrates. In addition, by emitting sounds with a phase difference (e.g., opposite phase) from the first sound outlet 1111 and the second sound outlet 1112, the sounds with a phase difference can interfere with each other in the far field, forming an effect of reducing sound leakage. In some embodiments, in order to reduce or avoid the interference and cancellation of the sounds emitted by the first sound outlet 1111 and the second sound outlet 1112 in the near field (e.g., the ear canal opening) from affecting the user's listening effect, the sound pressure of the sound emitted by the second sound outlet 1112 (or the second sound) can be less than the sound pressure of the sound emitted by the first sound outlet 1111 (or the first sound).

[0101] Because the sound pressure of the second sound emitted from the second sound outlet 1112 is less than the sound pressure of the first sound emitted from the first sound outlet 1111, the second and first sounds cancel each other out to the greatest extent at a position on the housing 110 closer to the second sound outlet 1112, thus forming an acoustic null point between the first and second sound outlets 1111 and 1112 at that position. Therefore, in the first and second sound outlets 1111 and 1112, the first microphone 131 or the second microphone 141 can be closer to the second sound outlet 1112, making its position closer to the acoustic null point of the speaker. This helps to minimize the possibility of the first microphone assembly 130 or the second microphone assembly 140 picking up the sound output from the first and / or second sound outlets 1111 and 1112. For example, when the second sound outlet 1112 is located on the outer surface, the second and first sounds can cancel out to a greater extent on the outer surface closer to the second sound outlet 1112. At this time, the acoustic zero point between the first sound outlet 1111 and the second sound outlet 1112 is located on or near the outer side, and correspondingly, the first sound receiving hole 131 can be located on the outer side. For example, when the second sound outlet 1112 is located on the outer side, the first sound receiving hole 131 can be located on the front or lower side, and its position is closer to the outer side. For another example, the second sound receiving hole 141 can be located on the upper side, and its position is closer to the outer side.

[0102] Thus, the sound picked up by the first microphone assembly 130 is mainly ambient noise, which can serve as the basis for noise reduction, simplifying the signal processing process and improving the noise reduction effect. In addition, by placing the first sound receiving hole 131 in the vicinity of the acoustic null point of the sound field jointly constructed by the first sound output hole 1111 and the second sound output hole 1112, it is also possible to prevent the user from picking up the voice of the other party output by the first sound output hole 1111 and the second sound output hole 1112 when making a call through the open-back headset 100, thereby reducing the echo heard by the other party (i.e., the voice of the other party).

[0103] In some embodiments, the first sound receiving hole 131 may be closer to the second sound output hole 1112, and the difference between the distance from the first sound receiving hole 131 to the first sound output hole 1111 and the distance from the first sound receiving hole 131 to the second sound output hole 1112 ranges from 1mm to 7mm. In some embodiments, the first sound receiving hole 131 may be closer to the second sound output hole 1112, and the difference between the distance from the first sound receiving hole 131 to the first sound output hole 1111 and the distance from the first sound receiving hole 131 to the second sound output hole 1112 ranges from 2mm to 6mm. In some embodiments, the first sound receiving hole 131 may be closer to the second sound output hole 1112, and the difference between the distance from the first sound receiving hole 131 to the first sound output hole 1111 and the distance from the first sound receiving hole 131 to the second sound output hole 1112 ranges from 3mm to 5.5mm. Since the acoustic null point of the sound field may be different at different frequencies, some embodiments of this specification limit the difference between the distance from the first sound receiving hole 131 to the first sound output hole 1111 and the distance from the first sound receiving hole 131 to the second sound output hole 1112 to the above range, which can ensure that the first sound receiving hole 131 is located at or near the acoustic null point of the corresponding sound field in a wider frequency range.

[0104] In some embodiments, the second microphone hole 141 may be closer to the second microphone hole 1112, and the difference between the distance from the second microphone hole 141 to the first microphone hole 1111 and the distance from the second microphone hole 141 to the second microphone hole 1112 ranges from 1mm to 5mm. In some embodiments, the second microphone hole 141 may be closer to the second microphone hole 1112, and the difference between the distance from the second microphone hole 141 to the first microphone hole 1111 and the distance from the second microphone hole 141 to the second microphone hole 1112 ranges from 2mm to 4.5mm. In some embodiments, the second microphone hole 141 may be closer to the second microphone hole 1112, and the difference between the distance from the second microphone hole 141 to the first microphone hole 1111 and the distance from the second microphone hole 141 to the second microphone hole 1112 ranges from 3mm to 4.25mm. Similar to the first microphone hole 131, by limiting the range of the difference between the distance from the second microphone hole 141 to the first sound outlet 1111 and the distance from the second microphone hole 141 to the second sound outlet 1112, the sound from the first sound outlet 1111 at the location of the second microphone hole 141 can be canceled out as much as possible with the sound from the second sound outlet 1112. This can minimize the possibility of the second microphone 140 picking up the sound output from the first sound outlet 1111 and the sound output from the second microphone hole 141, thereby improving the subsequent noise reduction effect.

[0105] When worn, the end of the shell 110 furthest from the support structure 120 (or the free end) extends at least partially into the user's concha (e.g., Figure 2 The first microphone 131 may be located on one of the front, outer, or lower sides of the housing 110, near the user's ear canal opening. For example, in the wearing state, the projection of the first microphone 131 onto the user's sagittal plane may be closer to the user's ear canal opening. This arrangement allows the ambient noise collected by the first microphone 130 to more closely resemble the ambient noise heard by the user, thereby improving the noise reduction effect when performing noise reduction processing based on the ambient noise collected by the first microphone 130. Figure 2 As shown, the first microphone hole 131 is located on the outer side of the housing 110, in the area directly above the user's ear canal opening. Therefore, the ambient noise is close to the noise actually heard by the user. Furthermore, the position of the first microphone hole 131 is far from the auricle and the support structure 120, and will not be blocked by the auricle, the support structure 120, or the housing 110 itself. This prevents the sound collected by the first microphone 130 from being reflected by the auricle, the support structure 120, or the housing 110 and thus failing to accurately reflect the actual noise transmitted to the user's ear canal opening. This further ensures that the ambient noise collected by the first microphone 130 is close to the noise actually heard by the user.

[0106] Figure 7This is a schematic diagram of an open-back headphone according to some embodiments of this specification. Figure 7 A side view of the open-back headphone 100 along its width is shown. Figure 7 As shown, the loudspeaker 160 has a central plane A. This central plane is a plane passing through the center point O of the loudspeaker 160 and perpendicular to the vibration direction of the diaphragm. The vibration direction of the diaphragm can be parallel or approximately parallel to the thickness direction Z of the housing 110. For example, if the loudspeaker 160 is a single-diaphragm loudspeaker, then the center point O of the loudspeaker 160 refers to the centroid of the single diaphragm. Furthermore, in combination with… Figure 5 As described above, the loudspeaker 160 may include a dual-diaphragm loudspeaker with a first diaphragm 161 and a second diaphragm 162. The center point O of the loudspeaker 160 refers to the midpoint of the distance between the first diaphragm 161 and the second diaphragm 162 in the vibration direction. The first diaphragm 161 and the second diaphragm 162 are symmetrical with respect to the center plane A and the center point O, respectively.

[0107] In some embodiments, such as Figure 7As shown, the first microphone hole 131 can be located on the outer surface OS of the housing 110, thereby bringing the position of the first microphone hole 131 closer to the acoustic null point between the first sound outlet hole 1111 and the second sound outlet hole 1112. Furthermore, compared to the rear surface BS of the housing 110, the position of the first microphone hole 131 can be closer to the front surface FS of the housing 110, thereby reducing the obstruction of the first microphone hole 131 by the ear and the housing 110 during wear, ensuring that the ambient noise collected by the first microphone assembly 130 is closer to the noise in the user's surrounding environment. In some embodiments, on the projection plane perpendicular to the width direction of the housing 110 (i.e., the plane jointly defined by the length direction Y and the thickness direction Z), the angle θ1 between the line B connecting the acoustic null point between the first sound outlet hole 1111 and the second sound outlet hole 1112 and the center point O of the speaker 160 and the center plane A of the speaker 160 is approximately 19°. Therefore, on the projection plane, the angle θ2 between the line C connecting the first microphone hole 131 and the center point O of the speaker 160 and the center plane A of the speaker 160 can be in the range of 5°-50°. This arrangement allows the position of the first microphone hole 131 to be closer to the acoustic null point of the speaker, thereby minimizing the possibility of the first microphone assembly 130 picking up the sound output from the first sound outlet 1111 and / or the second sound outlet 1112. Furthermore, by setting the angle θ2 within the range of 5°-50°, the vector L formed by the second microphone hole 141 and the first microphone hole 131 on the upper side of the housing 110 can point towards the user's mouth, allowing the microphone array formed by the first microphone assembly 130 and the second microphone assembly 140 to better pick up the sound emitted from the user's mouth, improving call quality. In some embodiments, to ensure that the vector L formed by the second microphone hole 141 and the first microphone hole 131 points towards the user's mouth while further bringing the position of the first microphone hole 131 closer to the acoustic null point of the speaker, the angle θ2 can be in the range of 10°-40°. In some embodiments, in order to ensure that the vector L formed by the second microphone hole 141 and the first microphone hole 131 can point to the user's mouth, while making the position of the first microphone hole 131 closer to the acoustic zero point of the speaker, the included angle θ2 can be in the range of 15°-25°.

[0108] What needs to be known is that Figure 7 The arrangement of the first microphone hole 131 on the outer side OS shown is merely illustrative. In some embodiments, the first microphone hole 131 may also be located on the front side or the lower side. For example, the first microphone hole 131 may be located on the front side, and its position may be closer to the outer side, so that the resulting included angle θ2 is within the aforementioned range. As another example, the first microphone hole 131 may be located on the lower side, and its position may be closer to the outer side, so that the resulting included angle θ2 is within the aforementioned range.

[0109] In some embodiments, the distance between the first sound receiving hole 131 and the first sound output hole 1111 and / or the second sound output hole 1112 can be set so that the first sound receiving hole 131 is as far away as possible from the first sound output hole 1111 and / or the second sound output hole 1112, thereby reducing or preventing the first microphone 130 from picking up the sound output from the first sound output hole 1111 and / or the second sound output hole 1112. In some embodiments, the distance between the first sound receiving hole 131 and the first sound output hole 1111 can be greater than a first preset threshold. For example, the first preset threshold can be 12mm. Another example is that the first preset threshold can be 13mm. Yet another example is that the first preset threshold can be 14mm. In some embodiments, the distance between the first sound receiving hole 131 and the second sound output hole 1112 can be greater than a second preset threshold. For example, the second preset threshold can be 5mm. Another example is that the second preset threshold can be 6mm. Yet another example is that the second preset threshold can be 7mm.

[0110] As described above, the second microphone hole 141 is located on the upper side of the housing 110. When worn, the earlobe, support structure 120, and housing 110 partially obstruct the second microphone hole 141, reducing the impact of airflow along the sagittal axis from the front to the back of the user's body on the second microphone hole 141. This effectively reduces wind noise in the external sound collected by the second microphone hole 141. Furthermore, to bring the second microphone hole 141 closer to the second sound outlet 1112, thus placing it closer to the acoustic null point of the speaker, and further minimizing the possibility of the second microphone assembly 140 collecting sound output from the first sound outlet 1111 and / or the second sound outlet 1112, the second microphone hole 141 is positioned closer to the outer side on the upper side. For example, in the thickness direction Z, the second sound receiving hole 141 has a first distance from the outer side and a second distance from the inner side. In some embodiments, to allow the second sound receiving hole 141 to be closer to the second sound output hole 1112, thereby bringing the position of the second sound receiving hole 141 closer to the acoustic null point of the speaker, the ratio between the first distance and the second distance can be in the range of 0.1-0.9. In some embodiments, to allow the second sound receiving hole 141 to be even closer to the second sound output hole 1112, thereby bringing the position of the second sound receiving hole 141 even closer to the acoustic null point of the speaker, the ratio between the first distance and the second distance can be in the range of 0.1-0.7. In some embodiments, to allow the second sound receiving hole 141 to be even closer to the second sound output hole 1112, thereby bringing the position of the second sound receiving hole 141 even closer to the acoustic null point of the speaker, the ratio between the first distance and the second distance can be in the range of 0.1-0.5.

[0111] Figure 8 This is a schematic diagram showing multiple exemplary positions of the second microphone hole according to some embodiments of this specification. For example... Figure 8 As shown, the second microphone hole 141 can be located on the upper side US of the housing 110, and can be located at any one of positions 1-6. Among them, positions 1, 3, and 5 are closer to the inner side IS of the housing 110 and are evenly distributed along the length Y direction from the rear side BS to the front side FS; positions 2, 4, and 6 are closer to the outer side of the housing 110 and are evenly distributed along the length Y direction from the rear side BS to the front side FS. Figure 9 The second microphone hole is located at... Figure 8 Frequency response curves of sound collected at several exemplary locations are shown. Figure 9 As shown, the horizontal axis represents frequency (Hz), the vertical axis represents sound pressure level (dB), curve 900 represents the frequency response curve of the sound collected by the third microphone component 170, and curves 901-906 represent the frequency response curves of the sound collected by the second microphone hole 141 when it is set in positions 1-6, respectively.

[0112] As described elsewhere in this specification, in order to more accurately reflect the sound in the user's ear canal, the third microphone assembly 170 has a third sound-receiving hole 171 located on the inner side of the housing 110. Therefore, the third sound-receiving hole 171 is closer to the first sound-emitting hole 1111, and the sound collected by the third microphone assembly 170 can be closer to the sound emitted from the first sound-emitting hole 1111. Thus, the degree of closeness between the sound collected by the second sound-receiving hole 141 and the sound collected by the third sound-receiving hole 171 can be used to represent the degree of closeness between the sound collected by the second sound-receiving hole 141 and the sound emitted by the first sound-emitting hole 1111. The closer the sound collected by the second sound-receiving hole 141 is to the sound emitted by the first sound-emitting hole 1111, the easier it is for the second sound-receiving hole 141 to collect the sound emitted by the first sound-emitting hole 1111, that is, the more easily the second sound-receiving hole 141 is interfered with by the first sound-emitting hole 1111.

[0113] This specification describes a method for comparing the sounds collected by the second microphone 141 at positions 1-6. The speaker 160 emits sound through the first sound outlet 1111 and the second sound outlet 1112, and acquires the sound collected by the third microphone assembly 170 and the sounds collected by the second microphone assembly 140 at positions 1-6. Furthermore, by comparing curve 900 with curves 901-906, the similarity between the sound collected by the second microphone 141 and the sound emitted by the first sound outlet 1111 can be determined. It should be noted that... Figure 9The sound collected by the second microphone assembly 140 and the third microphone assembly 170 shown refers to the sound emitted by the speaker 160, which is collected by both microphone assemblies. For example, the sound collection process can be carried out in a test environment with minimal ambient noise. In this case, when the speaker 160 emits sound through the first sound outlet 1111 and the second sound outlet 1112, it can be assumed that the sound collected by the third microphone assembly 170 and the second microphone assembly 140 only includes the sound emitted by the speaker 160.

[0114] For example, if a curve among curves 901-906 is closer to curve 900, it means that the sound corresponding to that curve is closer to the sound emitted by the first sound outlet 1111, that is, the second sound receiving hole 141 located at the corresponding position is more easily interfered with by the first sound outlet 1111. Figure 9 As shown, compared to curves 901, 903, and 905, curves 902, 904, and 906 are further away from curve 900, indicating that when the second microphone 141 is positioned at any of positions 2, 4, and 6, less sound is collected from the first output microphone 1111, i.e., it is closer to the acoustic zero point. Therefore, the second microphone 141 can be positioned on the upper side US closer to the outer side OS.

[0115] Furthermore, comparing curves 902, 904, and 906 reveals that when the second microphone hole 141 is positioned closer to the front side FS, the corresponding curve deviates further from curve 900. This indicates that when the second microphone hole 141 is positioned closer to the front side FS, less sound emitted from the first sound outlet 1111 can be collected, meaning it is closer to the acoustic zero point. Therefore, position 4 or position 6 can be selected as the second microphone hole 141.

[0116] In some embodiments, the distance between the second microphone 141 and the first microphone 1111 and / or the second microphone 1112 can be set to keep the second microphone 141 as far away from the first microphone 1111 and / or the second microphone 1112 as possible, thereby reducing or preventing the second microphone 140 from picking up the sound output from the first microphone 1111 and / or the second microphone 1112. In some embodiments, the distance between the second microphone 141 and the first microphone 1111 can be greater than a third preset threshold. For example, the third preset threshold can be 7 mm. Another example is that the third preset threshold can be 8 mm. Yet another example is that the third preset threshold can be 9 mm. In some embodiments, the distance between the second microphone 141 and the second microphone 1112 can be greater than a fourth preset threshold. For example, the fourth preset threshold can be 7 mm. Another example is that the fourth preset threshold can be 8 mm. Yet another example is that the fourth preset threshold can be 9 mm.

[0117] Figure 10This is a schematic diagram of the structure of a first microphone assembly according to some embodiments of this specification. For example... Figure 10 As shown, the first microphone assembly 130 is disposed inside the housing 110. The housing 110 is provided with a first sound receiving hole 131 corresponding to the first microphone assembly 130, through which the first microphone assembly 130 receives external sound. The first microphone assembly 130 may include a first microphone 132, a structural component 133, and an acoustic barrier 134.

[0118] In some embodiments, the first microphone 132 may be supported on a bracket 180 fixed inside the housing 110 (e.g., inside the connector 112). Figure 10 As shown, the bracket 180 is provided with a recess for accommodating the first microphone 132, and the first microphone 132 is disposed in the recess. In some embodiments, the peripheral sidewall of the first microphone 132 can be fixedly connected to the inner sidewall of the recess by adhesive.

[0119] Structural component 133 can be located between the first microphone 132 and the first sound receiving port 131. For example... Figure 10 As shown, the housing 110 may have an opening 1113 corresponding to the structural member 133, and at least a portion of the structural member 133 may be disposed in the opening 1113. The structural member 133 includes a main body 1331 and an extension 1332. The main body 1331 covers the first microphone 132 and is connected to the upper surface of the first microphone 132 facing the first sound receiving hole 131. For example, the first microphone 132 may include a sound inlet hole 1321, and the main body 1331 may be sealed to the upper surface of the first microphone 132 in the area around the sound inlet hole 1321 using double-sided tape, glue, etc. The extension 1332 may extend towards the bracket 180 from the periphery of the first microphone 132, thereby supporting it on the bracket 180 and achieving support and fixation of the structural member 133.

[0120] The structural component 133 is provided with a first sound-guiding channel 1333 for connecting the first sound-receiving hole 131 and the first microphone 132. The position of the first sound-guiding channel 1333 can correspond to the position of the sound inlet hole 1321 of the first microphone 132, thereby realizing the connection between the first sound-receiving hole 131 and the first microphone 132. In some embodiments, the length of the first sound-guiding channel 1333 can be within a preset range. On the one hand, this ensures that the first sound-guiding channel 1333 has sufficient length to attenuate wind noise from external sounds; on the other hand, it prevents the length of the first sound-guiding channel 1333 from being too long, which would increase the path of sound reaching the first microphone 132 and thus cause signal delay. In some embodiments, the preset range can be 1mm-5mm. In some embodiments, in order to further attenuate wind noise from external sounds and reduce signal delay, the preset range can be 1mm-3mm.

[0121] In some embodiments, a mesh or breathable membrane 1323 may be provided between the first microphone 132 and the first sound channel 1333. The mesh or breathable membrane 1323 can serve to prevent water or dust from entering the first microphone 132 without affecting the acquisition of sound signals by the first microphone 132.

[0122] The acoustic barrier 134 is installed on the side of the structural member 133 away from the first microphone 132. For example... Figure 10 As shown, the acoustic barrier 134 is disposed on the side of the structure 133 away from the first microphone 132, and the edge 1341 of the acoustic barrier 134 can extend toward the inner wall of the opening 1113, thereby being fixedly supported on the inner wall of the opening 1113. For example, a boss 11131 can be provided on the inner wall of the opening 1113, and the edge 1341 of the acoustic barrier 134 can be supported on the boss 11131.

[0123] By providing an acoustic barrier 134 on the side of the structural component 133 away from the first microphone 132, the airflow entering the first microphone 132 can be dispersed, reducing wind speed. This reduces wind noise in the ambient noise collected by the first microphone 132, improving the noise reduction effect when processing ambient noise based on the first microphone 130. Furthermore, the acoustic barrier 134 does not affect the amplitude and phase of the ambient noise collected by the first microphone 130, ensuring the accuracy of the ambient noise collected by the first microphone 130 and thus guaranteeing the noise reduction effect.

[0124] In some embodiments, to ensure the effectiveness of the acoustic barrier 134 in reducing wind noise, while preventing the acoustic barrier 134 from affecting the sound acquisition of the first microphone 132 due to excessive acoustic impedance, the acoustic impedance of the acoustic barrier 134 can be in the range of 25 MKS Rayls to 200 MKS Rayls. In some embodiments, to further improve the effectiveness of the acoustic barrier 134 in reducing wind noise, while preventing the acoustic barrier 134 from affecting the sound acquisition of the first microphone 132 due to excessive acoustic impedance, the acoustic impedance of the acoustic barrier 134 can be in the range of 90 MKS Rayls to 150 MKS Rayls.

[0125] In some embodiments, the acoustic barrier 134 can have a sufficiently large effective area to ensure its effectiveness in reducing wind noise. The effective area refers to the unobstructed surface area of ​​the acoustic barrier 134 facing the first microphone 132, wherein the surface area includes the area of ​​the perforated region containing the holes in the acoustic barrier 134 and the area of ​​the non-perforated region surrounding the holes. For example, the effective area of ​​the acoustic barrier 134 can be greater than 5 mm². 2A large effective area acoustic barrier mesh 134 provides ample space to disperse airflow and reduce wind speed. It also offers more pore paths, extending the contact time between the airflow and the mesh surface, increasing viscous dissipation, and thus ensuring the acoustic barrier mesh 134's effectiveness in reducing wind noise. In some embodiments, considering structural size limitations, the effective area of ​​the acoustic barrier mesh 134 can be within a preset range. For example, the effective area of ​​the acoustic barrier mesh 134 can be 5 mm². 2 -30mm 2 Within a certain range. For example, to further improve the wind noise reduction effect of the acoustic barrier 134, while considering structural size limitations, the effective area of ​​the acoustic barrier 134 can be within 10mm². 2 -25mm 2 Within a certain range. For example, to further improve the wind noise reduction effect of the acoustic barrier 134, while also considering structural size limitations, the effective area of ​​the acoustic barrier 134 can be within 15mm². 2 -20mm 2 Within the range.

[0126] As described above, the edge 1341 of the acoustic barrier 134 can extend toward the inner wall of the opening 1113, thereby achieving support and fixation of the acoustic barrier 134. In some embodiments, considering structural size limitations, the extension length of the edge 1341 of the acoustic barrier 134 can be in the range of 0.2mm-2mm. In some embodiments, further considering structural size limitations, the extension length of the edge 1341 of the acoustic barrier 134 can be in the range of 0.4mm-1.5mm. In some embodiments, further considering structural size limitations, the extension length of the edge 1341 of the acoustic barrier 134 can be in the range of 0.6mm-1mm.

[0127] In some embodiments, the side of the structural member 133 facing the first sound-receiving hole 131 may have a groove 1335. The groove 1335 may cooperate with the acoustic barrier 134 to form a cavity, which is acoustically connected to the first sound-guiding channel 1333. By having the groove 1335 cooperate with the acoustic barrier 134 to form a cavity, the flow velocity of the airflow through the acoustic barrier 134 is further reduced in the cavity, and the energy is further dissipated, thereby further reducing wind noise in the ambient noise sound collected by the first microphone 132.

[0128] Figure 11 This is a frequency response curve of wind noise collected by a first microphone when a groove or acoustic barrier is provided and not provided on the structural component shown in some embodiments of this specification, wherein the acoustic barrier is a steel mesh. Figure 11As shown, the horizontal axis represents frequency (Hz), and the vertical axis represents sound pressure level (dB). Curve 1101 represents the frequency response curve of wind noise collected by the first microphone assembly 130 when no groove and steel mesh are set. Curve 1102 represents the frequency response curve of wind noise collected by the first microphone assembly 130 when a groove is set but no steel mesh is set. Curve 1103 represents the frequency response curve of wind noise collected by the first microphone assembly 130 when both a groove and steel mesh are set.

[0129] according to Figure 11 By incorporating grooves, wind noise collected by the first microphone assembly 130 can be effectively reduced in the frequency range below 1000Hz. Furthermore, by simultaneously incorporating both grooves and a steel mesh, wind noise collected by the first microphone assembly 130 can be further reduced in the frequency range below 300Hz. As mentioned earlier, wind noise is primarily concentrated in the low-frequency range below 1000Hz; therefore, simultaneously incorporating grooves and a steel mesh can effectively reduce wind noise collected by the first microphone assembly 130.

[0130] In some embodiments, the first microphone 132 may include a motherboard 1322 for implementing signal processing, function control, and interface communication functions of the first microphone 132. In some embodiments, the acoustic barrier 134 may be made of metallic or non-metallic materials. As an example only, the acoustic barrier 134 may include a steel mesh. In some embodiments, when the acoustic barrier 134 is made of metallic material, the first microphone assembly 130 may further include a metal component 135. The acoustic barrier 134 can be electrically connected to the motherboard 1322 via the metal component 135. For example, as... Figure 10 As shown, the motherboard 1322 can be positioned between the first microphone 132 and the structural component. One end of the metal component 135 can be connected to the inner surface of the acoustic barrier 134. The structural component 133 can include a structural channel 1334 isolated from the first acoustic channel 1333. The other end of the metal component 135 can pass through the structural channel 1334 and connect to the motherboard 1322, thereby achieving electrical conductivity between the acoustic barrier 134 and the motherboard 1322. The isolation of the structural channel 1334 from the first acoustic channel 1333 means that the structural channel 1334 is not acoustically connected to the first acoustic channel 1333. For example, before the metal component 135 is assembled, the structural channel 1334 can be a hollow channel, allowing the other end of the metal component 135 to pass through the structural channel 1334 and connect to the motherboard 1322. After the metal part 135 is assembled, the structural channel 1334 can be sealed and filled with filler (e.g., glue) to prevent the structural channel 1334 from acoustically communicating with the first sound channel 1333 and affecting the acoustic performance of the first sound channel 1333 and / or the first microphone 132.

[0131] The acoustic barrier 134 is electrically connected to the motherboard 1322 of the first microphone 132 by setting the metal part 135. The static electricity generated by the acoustic barrier 134 under the action of airflow friction, etc. can be conducted to the motherboard 1322 through the metal part 135. At this time, it can be considered that the static electricity is grounded through the metal part 135, thereby avoiding static electricity interference to the first microphone 132 (for example, static electricity may interfere with sensitive electronic components (such as preamplifier) ​​in the first microphone 132, or even break down the first microphone 132).

[0132] Figure 12 This is a schematic diagram of the structure of a second microphone assembly according to some embodiments of this specification. For example... Figure 12 As shown, the second microphone assembly 140 is at least partially disposed inside the housing 110. Specifically, the upper side US of the housing 110 may have an opening for accommodating the second microphone assembly 140. A portion of the second microphone assembly 140 is accommodated inside the housing 110 through the opening, while another portion protrudes outside the housing 110. The upper side US of the housing 110 may have a protrusion 1114, which covers the portion of the second microphone assembly 140 protruding outside the housing 110. The second sound-receiving hole 141 of the second microphone assembly 140 may be formed on the protrusion 1114 to receive external sound. By disposing of the second microphone assembly 140 at least partially inside the housing 110, the housing 110 can be used to position or fix the second microphone assembly 140, while also reducing the space occupied by the second microphone assembly 140 within the housing 110, which is beneficial for structural miniaturization.

[0133] like Figure 12 As shown, the second microphone assembly 140 may include a second microphone 142 and a second sound-guiding channel 143. The second sound-guiding channel 143 is used to connect the second sound-receiving port 141 and the second microphone 142.

[0134] In some embodiments, the second microphone 142 may be mounted on the speaker 160 of the open-back headphone 100. For example, a recess 1671 may be provided on the speaker 160, and at least a portion of the second microphone 142 may be embedded within the recess 1671. Figure 5 and Figure 12 The speaker 160 of the open-back headphone 100 may include a magnetic circuit assembly 163 and two diaphragms (i.e., a first diaphragm 161 and a second diaphragm 162) located on both sides of the magnetic circuit assembly 163 and symmetrical about the central plane A. Specifically, the recess 1671 may be made of the magnetic circuit assembly 163 (e.g., magnet 1631, magnet 1631, magnet 1632, magnet 163 ... Figure 5The magnetic circuit assembly 163 includes a magnet 1631, a first magnetic plate 1632, a second magnetic plate 1633, etc., as shown. A groove 1671 can be disposed on the side of the magnetic circuit assembly 163 facing the upper side US of the housing. The second microphone 142 is embedded in the groove 1671, thereby receiving external sound through a second sound-receiving hole 141 located on the upper side US. Exemplarily, the magnetic circuit assembly 163 includes a magnet 1631, a first magnetic plate 1632, and a second magnetic plate 1633, and the groove 1671 can be formed by the magnet 1631, the first magnetic plate 1632, and the second magnetic plate 1633.

[0135] Furthermore, in some embodiments, the loudspeaker 160 may also include a loudspeaker housing 167, which surrounds the magnetic circuit assembly 163 and is used to carry the various components in the loudspeaker 160. Specifically, the loudspeaker housing 167 may be provided with an opening corresponding to the groove 1671, or the loudspeaker housing 167 may be recessed in the area corresponding to the groove 1671 to form a housing groove corresponding to the groove 1671.

[0136] By providing a groove 1671 on the speaker housing 160 and embedding the second microphone 142 into the groove 1671, the second microphone 142 can be moved downwards, reducing the width dimension of the housing 110 and facilitating structural miniaturization. Furthermore, since the second microphone hole 141 is closer to the outer surface OS of the housing, moving the second microphone 142 downwards increases the distance between the second microphone hole 141 and the second microphone 142, thus preventing the second sound channel 143 between the second microphone hole 141 and the second microphone 142 from being excessively tilted and increasing manufacturing difficulty.

[0137] like Figure 12 As shown, the first diaphragm 161 and the second diaphragm 162 are located on both sides of the magnetic circuit assembly 163 and are symmetrical about the central plane A, which passes through the center of the magnet 1631. To avoid altering other components around the magnet 1631 (e.g., ...), Figure 5 The structure of the first magnetic plate 1632, the second magnetic plate 1633, the first voice coil 164, the second voice coil 165, etc., shown can affect the acoustic characteristics of the speaker 160. When setting the groove 1671, only the size of the magnet 1631 needs to be reduced without changing the structure of other components around the magnet 1631. For example, the groove 1671 can be symmetrical about the central plane A, so that the position of the groove 1671 corresponds to the position of the magnet 1631. In this case, only the size of the magnet 1631 in the length direction Y needs to be reduced without affecting the acoustic characteristics of the speaker 160.

[0138] As described above, the inner surface IS of the housing 110 is provided with a first sound outlet 1111, and the outer surface OS of the housing 110 is provided with a second sound outlet 1112. To allow the second microphone hole 141 to be closer to the second sound outlet 1112, thereby bringing the position of the second microphone hole 141 closer to the acoustic null point of the speaker and minimizing the possibility of the second microphone assembly 140 picking up sound output from the first sound outlet 1111 and / or the second sound outlet 1112, the second microphone hole 141 can be placed closer to the second sound outlet 1112. For example, the second microphone hole 141 can be placed closer to the outer surface OS of the housing 110. Accordingly, as... Figure 12 As shown, in the direction along the second microphone 142 to the second sound hole 141, the second sound channel 143 is inclined toward the outer side OS.

[0139] In some embodiments, to position the second sound-receiving hole 141 closer to the acoustic null point of the loudspeaker, while also considering the manufacturing difficulty of the second sound-guiding channel 143, the tilt angle of the second sound-guiding channel 143 is in the range of 0-60°. In some embodiments, to position the second sound-receiving hole 141 even closer to the acoustic null point of the loudspeaker, while also considering the manufacturing difficulty of the second sound-guiding channel 143, the tilt angle of the second sound-guiding channel 143 is in the range of 20°-40°.

[0140] In some embodiments, the length of the second sound-guiding channel 143 can be within a preset range. This ensures that the second sound-guiding channel 143 has sufficient length to attenuate wind noise from external sounds, while preventing the second sound-guiding channel 143 from being too long and increasing the path of sound to the second microphone 142, thus causing signal delay. In some embodiments, the preset range can be 1mm-5mm. In some embodiments, to further attenuate wind noise from external sounds and reduce signal delay, the preset range can be 1mm-3mm.

[0141] Figure 13 This is a schematic diagram of the structure of a third microphone assembly according to some embodiments of this specification. For example... Figure 13 As shown, the third microphone assembly 170 is at least partially disposed inside the housing 110 and receives external sound through the third sound receiving hole 171. The third microphone assembly 170 may include a third microphone 172 and a third sound receiving channel 173. The third sound receiving channel 173 is used to connect the third sound receiving hole 171 and the third microphone 172.

[0142] The third microphone assembly 170 can be used to collect signals from the ear canal. For example, the third microphone assembly 170 can be used in conjunction with the first microphone assembly 130 and / or the second microphone assembly 140, wherein the first microphone assembly 130 and / or the second microphone assembly 140 can act as feedforward microphones to collect ambient noise, which is used to generate a first noise reduction signal, while the third microphone assembly 170 can act as a feedback microphone to collect a second noise reduction sound from the ear canal, thereby adjusting the first noise reduction signal based on the second noise reduction sound to further eliminate residual noise in the user's ear canal. In order to more accurately reflect the sound in the user's ear canal, the third microphone assembly 170, acting as a feedback microphone, can be closer to the user's ear canal than the first microphone assembly 130 and / or the second microphone assembly 140, which act as feedforward microphones. Therefore, the third microphone hole 171 can be located on the inner side of the housing 110 and closer to the user's ear canal opening. For example, the third microphone hole 171 can be closer to the user's ear canal than the first microphone hole 131 and the second microphone hole 141. For example, the third microphone assembly 170 may not be used in conjunction with the first microphone assembly 130 or the second microphone assembly 140. In this case, the open-back headphone 100 may include only the third microphone assembly 170. The third microphone assembly 170 can collect noise in the ear canal, and the processing circuit 150 can directly generate a first noise-reducing signal based on the collected noise in the ear canal. The speaker 160 can generate a noise-reducing sound with the same amplitude but opposite phase to the noise in the ear canal based on the first noise-reducing signal, thereby eliminating the noise in the user's ear canal.

[0143] like Figure 13As shown, the inner surface IS of the housing 110 may be provided with an opening for accommodating the third microphone assembly 170. A portion of the third microphone assembly 170 is accommodated inside the housing 110 through the opening, while another portion of the third microphone assembly 170 protrudes outside the housing 110. The inner surface IS of the housing 110 may be provided with a protrusion 1115, which can cover the portion of the third microphone assembly 170 protruding outside the housing 110. The third microphone hole 171 may be disposed on the protrusion 1115. By disposing of the third microphone hole 171 on the protrusion 1115, the third microphone hole 171 can be positioned closer to the user's ear canal, thereby allowing the signal collected by the third microphone 172 to more accurately reflect the sound in the user's ear canal. Furthermore, since the first sound outlet 1111 is located on the inner surface IS, by placing the third sound receiving hole 171 on the protrusion 1115, the third sound receiving hole 171 can be further away from the first sound outlet 1111, reducing or avoiding the third microphone 172 from picking up the sound emitted by the first sound outlet 1111, thereby improving the consistency between the signal picked up by the third microphone 172 and the signal at the ear canal. In some embodiments, in order to further distance the third sound receiving hole 171 from the first sound outlet 1111, thereby reducing or avoiding the third microphone 172 from picking up the sound emitted by the first sound outlet 1111 and improving the consistency between the signal picked up by the third microphone 172 and the signal at the ear canal, the height of the protrusion 1115 relative to the inner surface IS can be greater than 0.5mm. In some embodiments, to avoid the protrusion 1115 being too high and contacting the user's ear, causing blockage or affecting wearing comfort, the height of the protrusion 1115 relative to the inner surface IS can be in the range of 0.5mm-3mm. In some embodiments, in order to further improve the consistency between the signal collected by the third microphone 172 and the signal at the ear canal, while avoiding blockage or affecting wearing comfort, the height of the protrusion 1115 relative to the inner surface IS protrusion can be in the range of 1.1mm-1.6mm.

[0144] Figure 14 This is a schematic diagram of an open-back headphone according to some embodiments of this specification. In some embodiments, the support structure 120 may be symmetrical along a central plane D, which is parallel to the extending direction of the support structure 120. Due to the special structure of the ear, in order to ensure that the shell 110 fits the user's ear when worn, the central plane D of the support structure 120 may not coincide with the central plane A of the speaker 160 (or the central plane of the shell 110). For example, as Figure 14As shown, the center plane A of the speaker 160 (or the center plane of the housing 110) can be tilted inwards towards the side IS relative to the support structure 120, so that the housing 110 is tilted towards the user's ear when worn, thereby allowing the housing 110 to fit more snugly against the user's ear when worn. On the projection plane perpendicular to the width direction X of the housing 110 (i.e., the plane jointly defined by the length direction Y and the thickness direction Z), the center plane D of the support structure 120 and the center plane A of the speaker 160 can have an angle θ3. In some embodiments, to ensure that the housing 110 fits the user's ear when worn and to ensure wearing comfort, the angle θ3 can be in the range of 0-10°. In some embodiments, to ensure that the housing 110 fits the user's ear even more snugly when worn and to ensure wearing comfort, the angle θ3 can be in the range of 3°-6°.

[0145] In some embodiments, the protrusion height of the protrusion 1115 relative to the inner surface IS is related to the included angle θ3. For example, a larger included angle θ3 indicates that the housing 110 is more tilted towards the user's ear, and the protrusion 1115 is closer to the user's ear canal opening. Therefore, the protrusion height of the protrusion 1115 relative to the inner surface IS can be negatively correlated with the included angle θ3. For example, the included angle θ3 can be in the range of 0-3°, and correspondingly, the protrusion height of the protrusion 1115 relative to the inner surface IS can be in the range of 1.6mm-3mm. As another example, the included angle θ3 can be in the range of 3°-6°, and correspondingly, the protrusion height of the protrusion 1115 relative to the inner surface IS can be in the range of 1.1mm-1.6mm. As yet another example, the included angle θ3 can be in the range of 6°-10°, and correspondingly, the protrusion height of the protrusion 1115 relative to the inner surface IS can be in the range of 0.5mm-1.6mm.

[0146] When worn, the end of the shell 110 furthest from the support structure 120 (or the free end) extends at least partially into the user's concha (e.g., Figure 2 The free end is located either on the user's antihelix or on the rear side BS of the housing. Therefore, when worn, the free end of the housing 110 is closer to the user's ear canal opening.

[0147] In some embodiments, the protrusion 1115 may be disposed near the free end of the housing 110, thereby bringing the third microphone hole 171 closer to the user's ear canal opening. For example, to bring the third microphone hole 171 closer to the user's ear canal opening, thus making the collected second noise reduction closer to the sound at the ear canal opening, the distance between the protrusion 1115 and the free end of the housing 110 in the length direction Y of the housing 110 is less than 8 mm. As another example, to bring the third microphone hole 171 even closer to the user's ear canal opening, thus making the collected second noise reduction even closer to the sound at the ear canal opening, the distance between the protrusion 1115 and the free end of the housing 110 in the length direction Y of the housing 110 is less than 6 mm. As yet another example, to bring the third microphone hole 171 even closer to the user's ear canal opening, thus making the collected second noise reduction even closer to the sound at the ear canal opening, the distance between the protrusion 1115 and the free end of the housing 110 in the length direction Y of the housing 110 is less than 4 mm. The distance between the protrusion 1115 and the free end of the housing 110 refers to the distance between the edge of the protrusion 1115 near the free end and the free end. When the free end of the housing 110 is a curved surface, the distance between the protrusion 1115 and the free end of the housing 110 refers to the distance between the point of tangency of the tangent line parallel to the minor axis direction X at the free end and the protrusion 1115.

[0148] In some embodiments, to improve wearing comfort, the free end of the housing 110 may be curved. For example, as Figure 13As shown, the connection surface between the inner side IS and the rear side BS of the housing 110 is curved. This curved surface reduces the accommodating space at the free end, allowing the third microphone 172 to be positioned relatively far from the free end. Therefore, to bring the third microphone hole 171 closer to the user's ear canal opening, thereby making the acquired second noise reduction closer to the sound at the ear canal opening, the third sound channel 173 can be tilted towards the free end of the housing along the direction from the third microphone 172 to the third microphone hole 171. This allows the third microphone hole 171 to be close to the user's ear canal opening to acquire sound close to the ear canal opening even when the third microphone 172 is positioned far from the free end. In some embodiments, to bring the third microphone hole 171 even closer to the user's ear canal opening, thereby making the acquired second noise reduction closer to the sound at the ear canal opening, the distance between the center of the third microphone hole 171 and the edge of the protrusion 1115 in the longitudinal direction Y of the housing 110 can be less than 6 mm. Here, the edge of the protrusion 1115 refers to the point on the protrusion 1115 closest to the free end in the longitudinal direction Y of the housing 110. In some embodiments, to bring the third microphone hole 171 closer to the user's ear canal opening, thereby making the collected second noise reduction sound closer to the sound at the ear canal opening, the distance between the center of the third microphone hole 171 and the edge of the protrusion 1115 in the longitudinal direction Y of the housing 110 can be less than 4 mm. In some embodiments, to bring the third microphone hole 171 closer to the user's ear canal opening, thereby making the collected second noise reduction sound closer to the sound at the ear canal opening, the distance between the center of the third microphone hole 171 and the edge of the protrusion 1115 in the longitudinal direction Y of the housing 110 can be less than 2.5 mm.

[0149] In some embodiments, when worn, the distance between the third sound-receiving hole 171 and the user's ear canal opening can be in the range of 5mm-20mm, thereby making the collected second noise reduction closer to the sound at the ear canal opening and improving the noise reduction effect. In some embodiments, in order to make the collected second noise reduction even closer to the sound at the ear canal opening, while avoiding the third sound-receiving hole 171 being too close to the user's ear canal opening and affecting the sound field corresponding to the third sound-receiving hole 171, the distance between the third sound-receiving hole 171 and the user's ear canal opening can be in the range of 8mm-10mm when worn. The distance between the third sound-receiving hole 171 and the user's ear canal opening refers to the distance between the third sound-receiving hole 171 and a feature point on the ear canal opening. The feature point can be the point closest to the back of the ear in the projection of the ear canal opening onto the user's sagittal plane.

[0150] like Figure 13As shown, the surface of the protrusion 1115 is recessed inward to form a recessed plane 1116, and the opening of the third sound guide channel 173 (i.e., the third sound receiving hole 171) can be disposed on the recessed plane 1116. With this configuration, when the protrusion 1115 contacts the user's ear during wear, the third sound receiving hole 171, disposed on the recessed plane 1116 inside the protrusion 1115, avoids blockage caused by direct contact between the third sound receiving hole 171 and the user's ear due to differences in human ears or incorrect wearing methods, thereby ensuring the sound collection effect of the third microphone 172. In some embodiments, the opening area of ​​the recessed plane 1116 can be much larger than the opening area of ​​the third sound receiving hole 171. This configuration makes the recessed plane 1116, with its larger opening area, less likely to be completely blocked by the ear structure, thus creating a gap between the recessed plane 1116 and the ear structure that allows sound to pass through. The opening area of ​​the recessed plane 1116 refers to the area of ​​the opening of the recessed plane 1116 on its outermost side (i.e., the side of the recessed plane 1116 facing away from the third microphone 172). In some embodiments, to avoid the recessed plane 1116 being completely blocked by the ear structure, thereby creating a sufficient gap between the recessed plane 1116 and the ear structure to allow sound to pass through, the ratio between the opening area of ​​the recessed plane 1116 and the opening area of ​​the third microphone hole 171 is greater than 30. In some embodiments, to further avoid the recessed plane 1116 being completely blocked by the ear structure, thereby creating a sufficient gap between the recessed plane 1116 and the ear structure to allow sound to pass through, the ratio between the opening area of ​​the recessed plane 1116 and the opening area of ​​the third microphone hole 171 is greater than 20. In some embodiments, in order to further prevent the recessed plane 1116 from being completely blocked by the ear structure, thereby forming a gap between the recessed plane 1116 and the ear structure that allows sound to pass through, the ratio between the opening area of ​​the recessed plane 1116 and the opening area of ​​the third sound hole 171 is greater than 15.

[0151] In some embodiments, for ease of description, the first microphone assembly 130 may also be referred to as the front microphone assembly, and correspondingly, the first sound-receiving hole 131 may also be referred to as the front sound-receiving hole, the first sound-guiding channel 1333 may also be referred to as the front sound-guiding channel, and the groove 1335 may also be referred to as the front groove; the second microphone assembly 140 may also be referred to as the upper microphone assembly, and correspondingly, the second sound-guiding channel 143 may also be referred to as the upper sound-guiding channel, the second sound-receiving hole 141 may also be referred to as the upper sound-receiving hole, the protrusion 1114 may also be referred to as the upper protrusion, and the groove 1671 may also be referred to as the upper groove; the third microphone assembly 170 may also be referred to as the rear microphone assembly, and correspondingly, the third sound-guiding channel 173 may also be referred to as the rear sound-guiding channel, the third sound-receiving hole 171 may also be referred to as the rear sound-receiving hole, and the protrusion 1115 may also be referred to as the rear protrusion.

[0152] The basic concepts have been described above. It is clear that the above disclosure is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, various modifications, improvements, and corrections may be made to this specification by those skilled in the art. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0153] Furthermore, this specification uses specific terms to describe embodiments thereof. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Moreover, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.

[0154] Furthermore, those skilled in the art will understand that various aspects of this specification can be described and illustrated in several patentable ways, including any new and useful combinations of processes, machines, products, or substances, or any new and useful improvements thereof. Accordingly, various aspects of this specification can be implemented entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. All of the above hardware or software may be referred to as a “data block,” “module,” “engine,” “unit,” “component,” or “system.” Furthermore, various aspects of this specification may be represented as a computer product located on one or more computer-readable media, including computer-readable program code.

[0155] Furthermore, unless expressly stated in the claims, the order of elements and sequences, the use of numbers and letters, or other names in this specification are not intended to limit the order of the processes and methods described herein. Although various examples have been discussed in the foregoing disclosure of some embodiments of the invention that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments; rather, the claims are intended to cover all modifications and equivalent combinations that conform to the spirit and scope of the embodiments described herein. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely using software solutions, such as installing the described system on an existing server or mobile device.

[0156] Similarly, it should be noted that, in order to simplify the description disclosed herein and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of embodiments in this specification may sometimes combine multiple features into a single embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the subject matter of this specification requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of a single embodiment disclosed above.

[0157] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples by terms such as "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical data used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, the numerical data should take into account specified significant digits and employ general methods of digit reservation. Although the numerical ranges and data used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such numerical values ​​are set as precisely as feasible.

Claims

1. An open-back headphone, comprising: case; The support structure is configured to place the housing near the user's ear without obstructing the ear canal when worn; An upper microphone assembly receives external sound through an upper sound-receiving hole, wherein the upper side of the housing is provided with an upper protrusion, and the upper sound-receiving hole is disposed on the upper protrusion; The processing circuitry is configured to generate a noise-reduced signal based on external sound collected by the upper microphone assembly; and A loudspeaker, located within the housing, is configured to generate noise-canceling sound under the drive of the noise-canceling signal.

2. The open-back earphone according to claim 1, wherein the inner side of the housing is provided with a first sound outlet, the outer side of the housing is provided with a second sound outlet, and the upper microphone assembly includes an upper microphone and an upper sound-guiding channel disposed between the upper microphone and the upper sound-receiving hole, wherein, The upper sound channel is inclined toward the outer side in the direction from the upper microphone to the upper sound hole.

3. The open-back headphone according to claim 2, wherein the tilt angle of the upper sound channel is in the range of 0-60°.

4. The open-back headphones according to claim 2 or 3, wherein the tilt angle of the upper sound channel is in the range of 20-40°.

5. The open-back headphone according to claim 2 or 3, wherein the length of the upper sound channel is in the range of 1mm-3mm.

6. The open-back earphone according to any one of claims 1-3, wherein the upper side of the housing is provided with an opening for receiving the upper microphone assembly, a portion of the upper microphone assembly is received inside the housing through the opening, and another portion of the upper microphone assembly protrudes outside the housing.

7. The open-back headphone according to any one of claims 1-3, wherein the speaker includes a magnetic circuit assembly having an upper recess, and the upper microphone is at least partially embedded in the upper recess.

8. The open-back earphone according to claim 7, wherein the magnetic circuit assembly includes a magnet, a first magnetic plate and a second magnetic plate, and the upper groove is formed by the magnet, the first magnetic plate and the second magnetic plate.

9. The open-back earphone according to claim 7, wherein the upper groove is disposed on the upper side of the magnetic circuit assembly facing the housing.

10. The open-back headphone of claim 7, wherein the speaker further comprises two diaphragms located on both sides of the magnetic circuit assembly and symmetrical about the central plane, the upper groove being symmetrical about the central plane.

11. The open-back headphone of claim 10, wherein the two diaphragms are configured to vibrate synchronously in the same direction.

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