Open Type Earphones

Abstract

An open-type earphone according to an embodiment of the present specification includes an acoustic driver that generates two sounds with opposite phases, a housing that accommodates the acoustic driver and has two sound emission holes that output the two sounds with opposite phases, and a suspension structure that fixes the housing in a position near a user's ear so as not to block the user's ear canal, wherein the housing includes a main body and a baffle, the main body defines a first cavity that accommodates the acoustic driver, the baffle is connected to the main body and extends toward the user's ear canal and defines a second cavity together with the user's auricle, and the two sound emission holes are located inside and outside the second cavity, respectively.

Description

[Technical field]

[0001] The present specification relates to the field of acoustics, and in particular to open earphones.

[0002] [Incorporated by reference] This application claims priority to Chinese Application No. 202211336918.4, filed on October 28, 2022, the entire contents of which are incorporated herein by reference. [Background technology]

[0003] An earphone is a portable audio output device that can realize acoustic transmission. In order to solve the sound leakage problem of earphones, two or more sound sources are usually used to generate two acoustic signals with opposite phases. Under far-field conditions, the difference in acoustic distance to a specific point in the far-field of two sound sources with opposite phases can basically be ignored, so the two acoustic signals can be offset by each other to reduce the sound leakage in the far-field. Although this method can achieve a certain degree of sound leakage reduction effect, it still has certain limitations. For example, while suppressing the far-field acoustic signal, the volume of the near-field audio signal is also reduced, and the phase difference increases with the increase of the signal frequency, so that this method has a poor suppression effect on the far-field high-frequency signal.

[0004] Therefore, it is desirable to provide an earphone that can more effectively reduce sound leakage, which can increase the volume of near-field audio signals while simultaneously reducing the volume of far-field sound leakage. Summary of the Invention [Means for solving the problem]

[0005] An open-type earphone according to one embodiment of the present specification includes an acoustic driver that generates two sounds with opposite phases, a housing that accommodates the acoustic driver and has two sound emission holes that output the two sounds with opposite phases, and a suspension structure that fixes the housing in a position near a user's ear so as not to block the user's ear canal, wherein the housing includes a main body and a baffle, the main body defines a first cavity that accommodates the acoustic driver, the baffle is connected to the main body and extends toward the user's ear canal and defines a second cavity together with the user's auricle, and the two sound emission holes are located inside and outside the second cavity, respectively.

[0006] In some embodiments, the baffle is connected to a side of the body away from the user's face and has a thickness less than the thickness of the body.

[0007] In some embodiments, the ratio of the distance from a boundary of the baffle adjacent to the user's ear canal to a sound emission hole located outside the second cavity to the distance between two sound emission holes is less than 1.78.

[0008] In some embodiments, the distance from a boundary of the baffle adjacent to a user's ear canal to a sound emission hole located outside the second cavity is smaller than the distance between the two sound emission holes.

[0009] In some embodiments, the ratio of the volume of the second cavity to a reference volume is less than 1.75, and the reference volume is the cube of the distance from a boundary of the baffle adjacent to the user's ear canal to a sound emission hole located outside the second cavity.

[0010] In some embodiments, the ratio of the volume of the sound guided from the sound output hole located outside the second cavity to the volume of the sound guided from the sound output hole located inside the second cavity is in the range of 0.2 to 2.0.

[0011] In some embodiments, the open-type earphone further includes an acoustic structure that adjusts a ratio between a volume of sound guided from a sound output hole located outside the second cavity and a volume of sound guided from a sound output hole located inside the second cavity, and includes one of a slit, a conduit, a cavity, a gauze, or a porous medium.

[0012] In some embodiments, a sound emission hole located inside the second cavity is located between a user's ear canal and a sound emission hole located outside the second cavity.

[0013] In some embodiments, when the body is positioned in front of the user's tragus, the baffle has a lateral extension dimension in the range of 2mm to 22mm and a vertical extension dimension in the range of 2mm to 10mm.

[0014] In some embodiments, the effective area of ​​the baffle is 84 mm 2 ~1060mm 2 is within the range.

[0015] In some embodiments, one of the two sound emission holes is on the side of the body facing the tragus, and the other sound emission hole is on the side where the baffle is located.

[0016] In some embodiments, when the body is located within the auricle or overlaps with the auricle projection surface, the baffle has a longitudinal extension dimension of 1 cm or more or an effective area of ​​the baffle is 20 mm 2 That's all.

[0017] In some embodiments, one of the two sound emission holes is located on a side of the body toward the ear canal, and the other sound emission hole is located on a side of the body away from the ear canal.

[0018] In some embodiments, at least a portion of a user's ear canal is located within the second cavity.

[0019] In some embodiments, the housing at least partially covers the user's ear canal.

[0020] Another open-type earphone according to one embodiment of the present specification includes an acoustic driver that generates two sounds with opposite phases, a housing that accommodates the acoustic driver and has two sound emission holes that output the two sounds with opposite phases, and a suspension structure in which one end of the housing abuts against a user's concha cavity, wherein the housing defines a first cavity that accommodates the acoustic driver and defines a second cavity together with the concha cavity, and the two sound emission holes are located inside and outside the second cavity, respectively.

[0021] In some embodiments, the angle between the surface of the housing facing the triangular fossa and the tangent of the connection between the suspension structure and the housing is in the range of 100° to 150°.

[0022] In some embodiments, the ratio of the distance from the gap between the housing and the ear canal opening to a sound emission hole located outside the second cavity to the distance between the two sound emission holes is smaller than 1.78.

[0023] In some embodiments, the distance from a gap between the housing and the ear canal opening to a sound emission hole located outside the second cavity is smaller than the distance between the two sound emission holes.

[0024] In some embodiments, the ratio of the volume of the second cavity to a reference volume is less than 1.75, and the reference volume is the cube of the distance from the gap between the housing and the ear canal opening to a sound emission hole located outside the second cavity.

[0025] In some embodiments, the ratio of the volume of the sound guided from the sound output hole located outside the second cavity to the volume of the sound guided from the sound output hole located inside the second cavity is in the range of 0.2 to 2.0.

[0026] In some embodiments, the open-type earphone further includes an acoustic structure that adjusts a ratio between a volume of sound guided from a sound output hole located outside the second cavity and a volume of sound guided from a sound output hole located inside the second cavity, and includes one of a slit, a conduit, a cavity, a gauze, or a porous medium.

[0027] In some embodiments, a sound emission hole located inside the second cavity is located on a side of the housing facing an ear canal.

[0028] In some embodiments, the sound emission hole located outside the second cavity is located on the side of the housing facing the triangular fossa or on the side of the housing facing the earlobe.

[0029] In some embodiments, the distance between an upper surface of the housing along the user's vertical axis and a point of the suspension structure that contacts the user's ear along the user's vertical axis is in the range of 10 mm to 20 mm.

[0030] In some embodiments, the housing has a length along a longitudinal axis of the housing at a surface remote from a user's ear that is within a range of 20 mm to 30 mm.

[0031] In some embodiments, the housing has a length along a minor axis of the housing at a surface remote from a user's ear that is in the range of 11 mm to 16 mm.

[0032] The present specification will be further illustrated by example embodiments, which are not limiting and will be described in detail with reference to the drawings, in which like numbers refer to like structures. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 is a block diagram of an exemplary open-type earphone in accordance with some embodiments of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram of two point sound sources in accordance with some embodiments of the present disclosure. [Diagram 3] FIG. 1 is a schematic diagram of measuring sound leakage according to some embodiments herein. [Figure 4] FIG. 10 is a comparison diagram of sound leakage index at different frequencies for a single point sound source and dual point sound sources, in accordance with some embodiments herein. [Diagram 5] 11A-11C are frequency response curves at near-field listening positions for dipole sources with different spacings, in accordance with certain embodiments of the present disclosure. [Figure 6] FIG. 2 is a schematic diagram of two point sound sources and listening positions according to some embodiments of the present disclosure. [Figure 7] FIG. 13 illustrates a diagram of sound leakage index in the far field for differently spaced dipole sources, in accordance with certain embodiments herein. [Figure 8] FIG. 13 is an exemplary schematic diagram of a distribution of baffles placed around one of the dipole sound sources, in accordance with some embodiments herein. [Figure 9] FIG. 13 illustrates a sound leakage index with and without a baffle around one of the dipole sound sources, in accordance with some embodiments herein. [Figure 10] 1A-1C are schematic diagrams of a dipole source with a baffle at different listening positions in the near field, in accordance with some embodiments herein. [Figure 11] FIG. 11 illustrates frequency response curves of a baffled dipole source at different listening positions in the near field, in accordance with some embodiments of the present disclosure. [Figure 12] FIG. 13 is an exemplary schematic distribution diagram of a cavity structure placed around one of the dipole sound sources, according to some embodiments herein. [Figure 13] 1 is a schematic diagram of a dipole source structure and a principle when a cavity structure is placed around one of the dipole sources according to some embodiments of the present disclosure; FIG. [Figure 14A]FIG. 2 is a schematic diagram of a monopole source in accordance with certain embodiments of the present disclosure. [Figure 14B] FIG. 1 is a schematic diagram of a dipole sound source in accordance with certain embodiments of the present disclosure. [Figure 14C] FIG. 2 is a schematic diagram of a baffle structure disposed around one of the dipole sound sources, according to some embodiments herein; [Figure 14D] FIG. 2 is a schematic diagram of a cavity structure disposed around one of the dipole sound sources according to some embodiments of the present disclosure; [Figure 15A] FIG. 13 is a frequency response characteristic curve diagram of listening position and sound leakage of a monopole sound source according to some embodiments of the present disclosure. [Figure 15B] FIG. 1 is a frequency response characteristic curve diagram of listening position and sound leakage of a dipole sound source according to some embodiments of the present disclosure. [Figure 15C] FIG. 11 is a frequency response characteristic curve diagram of listening sound and sound leakage at a listening position when a baffle structure is installed around one of the dipole sound sources according to some embodiments of the present specification. [Figure 15D] FIG. 13 is a frequency response characteristic curve diagram of listening sound and sound leakage at a listening position when a cavity structure is installed around one of the dipole sound sources in accordance with some embodiments of the present disclosure. [Figure 16] FIG. 11 is a schematic diagram of hearing indexes when a baffle structure is placed around one of a monopole sound source, a dipole sound source, and a dipole sound source according to some embodiments of the present specification, and when a cavity structure is placed around one of a dipole sound source. [Figure 17] 1 is a schematic diagram of a cavity structure according to some embodiments of the present disclosure; [Figure 18] FIG. 13 illustrates a hearing index curve diagram of cavity structures with different sizes of leakage structures, in accordance with some embodiments herein. [Figure 19] FIG. 13 illustrates a hearing index curve diagram of a cavity structure having a leakage structure at different positions, in accordance with some embodiments herein. [Figure 20A]FIG. 13 illustrates hearing index curves at a frequency of 500 Hz for cavity structures having leakage structures at different positions and different sizes, according to some embodiments herein. [Figure 20B] FIG. 13 illustrates hearing index curve diagrams at a frequency of 1000 Hz for cavity structures having leakage structures at different positions and different sizes, according to some embodiments herein. [Figure 20C] FIG. 13 illustrates hearing index curves at a frequency of 2000 Hz for cavity structures having leakage structures at different positions and different sizes, according to some embodiments herein. [Figure 20D] FIG. 13 illustrates hearing index curve diagrams at a frequency of 5000 Hz for cavity structures having leakage structures at different positions and different sizes, according to some embodiments herein. [Figure 21A] 1 is a schematic diagram of a cavity structure having two horizontal openings, according to some embodiments herein. FIG. [Figure 21B] 1 is a schematic diagram of a cavity structure having two vertical openings, according to some embodiments herein. FIG. [Figure 22] FIG. 10 is a comparison diagram of hearing index curves of a cavity structure having two openings and a cavity structure having one opening, according to some embodiments herein. [Figure 23A] 1 is a schematic diagram of a cavity structure having one opening, according to some embodiments herein. FIG. [Figure 23B] 1 is a schematic diagram of a cavity structure having two openings, according to some embodiments herein. FIG. [Figure 23C] 1 is a schematic diagram of a three-opening cavity structure according to some embodiments herein. FIG. [Figure 23D] 1 is a schematic diagram of a cavity structure having four openings, according to some embodiments herein. FIG. [Figure 24] FIG. 11 is a comparison diagram of hearing index curves for cavity structures with different numbers of openings, in accordance with certain embodiments herein. [Figure 25A] 1 is a schematic diagram of a cavity structure having one opening, according to some embodiments herein. FIG. [Figure 25B] FIG. 10 is a comparison diagram of hearing index curves for different relative volumes of a cavity structure with one opening, according to some embodiments herein. [Figure 26A] 1 is a schematic diagram of a cavity structure having one opening, according to some embodiments herein. FIG. [Figure 26B] FIG. 11 is a comparison diagram of hearing indexes of cavity structures having different sound pressure ratio N values, in accordance with some embodiments herein. [Figure 27A] FIG. 26B is a diagram illustrating a hearing index curve at a frequency of 20 Hz when the cavity structure shown in FIG. 26A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Figure 27B] FIG. 26B is a diagram illustrating a hearing index curve at a frequency of 100 Hz when the cavity structure shown in FIG. 26A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with some embodiments herein. [Figure 27C] FIG. 26B is a diagram illustrating a hearing index curve at a frequency of 1000 Hz when the cavity structure shown in FIG. 26A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with some embodiments herein. [Figure 27D] FIG. 26B is a diagram illustrating a hearing index curve at a frequency of 10,000 Hz when the cavity structure illustrated in FIG. 26A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Figure 28A] 1 is a schematic diagram of a cavity structure having one opening, according to some embodiments herein. FIG. [Figure 28B] FIG. 28B illustrates a hearing index curve diagram at a frequency of 20 Hz when the cavity structure shown in FIG. 28A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments of the present disclosure. [Figure 28C] FIG. 28B is a diagram illustrating a hearing index curve at a frequency of 100 Hz when the cavity structure shown in FIG. 28A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Figure 28D]FIG. 28B is a diagram illustrating a hearing index curve at a frequency of 1000 Hz when the cavity structure illustrated in FIG. 28A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Figure 28E] FIG. 28B is a diagram illustrating a hearing index curve at a frequency of 10,000 Hz when the cavity structure illustrated in FIG. 28A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Figure 29A] 1 is a schematic diagram of a cavity structure having one opening, according to some embodiments herein. FIG. [Figure 29B] FIG. 29B illustrates a hearing index curve diagram at a frequency of 20 Hz when the cavity structure shown in FIG. 29A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments of the present disclosure. [Figure 29C] FIG. 29B is a diagram illustrating a hearing index curve at a frequency of 100 Hz when the cavity structure shown in FIG. 29A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Figure 29D] FIG. 29B is a diagram illustrating a hearing index curve at a frequency of 1000 Hz when the cavity structure shown in FIG. 29A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Figure 29E] FIG. 29B is a diagram illustrating a hearing index curve at a frequency of 10,000 Hz when the cavity structure shown in FIG. 29A has different sizes of leakage structures and different sound pressure ratios Nsource, in accordance with certain embodiments herein. [Diagram 30] FIG. 1 is a block diagram of an example open-type earphone in accordance with some embodiments of the present disclosure. [Diagram 31] FIG. 1 is a schematic diagram of an exemplary open-type earphone in accordance with some embodiments of the present disclosure. [Diagram 32] 1 is a schematic diagram of an example housing according to some embodiments herein. [Diagram 33] 1 is a schematic diagram of an example housing according to some embodiments herein. [Figure 34A]FIG. 1 shows the sound field of an open-back earphone without a baffle. [Figure 34B] FIG. 34 illustrates the sound field of an open-type earphone having the baffle shown in FIG. 33. [Diagram 35] FIG. 2 is a comparison diagram of frequency response curves of an open-back earphone without a baffle and an open-back earphone with a baffle. [Diagram 36] FIG. 2 is a curve diagram showing the difference between the listening volume and the sound leakage volume of an open-type earphone without a baffle and an open-type earphone with a baffle. [Figure 37A] FIG. 34 is a graph showing the change in sound volume at a frequency of 500 Hz for different horizontal and vertical extension dimensions of the baffle shown in FIG. 33. [Figure 37B] FIG. 34 is a graph showing the change in sound volume at a frequency of 1000 Hz for different horizontal and vertical extension dimensions of the baffle shown in FIG. 33. [Figure 37C] FIG. 34 is a graph showing the change in sound leakage volume for different horizontal and vertical extension dimensions of the baffle shown in FIG. 33 when the frequency is 500 Hz. [Figure 37D] FIG. 34 is a graph showing the change in sound leakage volume for different horizontal and vertical extension dimensions of the baffle shown in FIG. 33 when the frequency is 1000 Hz. [Figure 38] FIG. 1 is a schematic diagram of an exemplary open-type earphone in accordance with some embodiments of the present disclosure. [Figure 39] FIG. 10 is a comparison diagram of frequency response curves of an example open-back earphone with and without a baffle, in accordance with certain embodiments of the present disclosure. [Diagram 40] FIG. 1 is a schematic diagram of an exemplary open-type earphone in accordance with some embodiments of the present disclosure. [Diagram 41] FIG. 41 is a cross-sectional view taken along line AA of the open-type earphone shown in FIG. [Diagram 42] FIG. 2 is a front view of an exemplary open-back earphone as it would be placed on a user's ear, in accordance with some embodiments of the present disclosure. [Diagram 43] FIG. 43 is a plan view of the open-type earphone shown in FIG. 42 when it is worn in a user's ear. [Diagram 44] FIG. 43 is a bottom view of the open-type earphone shown in FIG. 42 when it is worn in a user's ear. [Diagram 45] FIG. 1 is a plan view of an exemplary open-type earphone in accordance with some other embodiments herein. [Diagram 46] FIG. 46 is a bottom view of the open-type earphone shown in FIG. [Figure 47] FIG. 1 is a plan view of an exemplary open-type earphone in accordance with some further embodiments of the present disclosure. [Figure 48] FIG. 48 is a bottom view of the open-type earphone shown in FIG. [Figure 49A] FIG. 1 is a schematic diagram of an exemplary open-type earphone according to some embodiments of the present disclosure; [Figure 49B] 1 is a schematic diagram of an ear according to some embodiments herein. [Figure 49C] 1 is a schematic diagram of an ear according to some embodiments herein. [Figure 50A] FIG. 1 is a schematic diagram of an exemplary open-type earphone according to some embodiments of the present disclosure; [Figure 50B] FIG. 1 is a schematic diagram of an exemplary open-type earphone according to some embodiments of the present disclosure; [Figure 50C] 1 is a schematic diagram of an ear according to some embodiments herein. [Figure 51] FIG. 1 is a schematic diagram of an exemplary open-type earphone according to some embodiments of the present disclosure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] In order to more clearly describe the technical means of the embodiments of the present application, the drawings necessary for the description of the embodiments are briefly described below. Obviously, the drawings described below are only some examples or embodiments of the present application, and those skilled in the art can apply the present application to other similar scenarios based on these drawings without creative efforts. Unless otherwise clear from the context or specified, in the drawings, the same symbols represent the same structures or operations.

[0035] It should be understood that the terms "system," "apparatus," "unit," and / or "module" used herein are ways of distinguishing between different levels of assemblies, parts, components, portions, or structures, however, other terms may be used in place of the above terms if they accomplish the same purpose.

[0036] As used herein and in the claims, unless the context clearly dictates otherwise, terms such as "a," "one," "one kind," and / or "the" do not specifically refer to the singular but may include the plural. In general, the terms "comprise" and "containing" are intended to indicate only the inclusion of explicitly identified steps and elements, and these steps and elements are not intended to be an exclusive listing, and a method or apparatus may also include other steps or elements.

[0037] In the embodiment of the present specification, an open type earphone is described. When a user wears the open type earphone, the open type earphone can fix the housing near the user's ear via a suspension structure at a position that does not block the user's ear canal. The open type earphone may be worn on the user's head (e.g., open type earphone worn in glasses or other structural manner), worn on other parts of the user's body (e.g., the user's neck / shoulder area), or placed near the user's ear in other manners (e.g., hand-held manner). The open type earphone may include an acoustic driver, a housing, and a suspension structure. The acoustic driver generates two sounds with opposite phases. The housing contains the acoustic driver, and is provided with two sound emission holes that respectively guide the two sounds with opposite phases.

[0038] In some embodiments, a suspension structure secures the housing in a position adjacent to the user's ear without blocking the user's ear canal. In some embodiments, the housing may include a body and a baffle. The body defines a first cavity that accommodates the acoustic driver. The baffle is connected to the body and extends toward the user's ear canal to define a second cavity together with the user's pinna. Two sound emission holes are located inside and outside the second cavity, respectively.

[0039] In some other embodiments, the suspension structure abuts one end of the housing (e.g., the end remote from the suspension structure) against the user's concha cavity. The housing defines a first cavity that accommodates the acoustic driver and defines a second cavity together with the concha cavity. Two sound emission holes are located inside and outside the second cavity, respectively.

[0040] In some embodiments of the present specification, by limiting at least one sound emission hole to the inside of the second cavity, most of the sound can be transmitted to the user's ear canal for near-field listening, improving the listening volume. At the same time, since a leakage structure (e.g., a gap, etc.) is installed in the second cavity, the sound emitted from the sound emission hole located inside the second cavity can be radiated outside the second cavity, and a sound cancellation effect can still be achieved in the far field with the sound emitted from another sound emission hole, thereby achieving a high sound leakage reduction effect.

[0041] FIG. 1 is a block diagram of an exemplary open-type earphone 100 according to some embodiments of the present disclosure. As shown in FIG. 1, the open-type earphone 100 may include an acoustic driver 110, a housing 120, and a suspension structure 130. In some embodiments, the open-type earphone 100 may have a housing 120 attached to a user's body (e.g., the head, neck, or upper torso of a human body) via the suspension structure 130, and at the same time, the housing 120 and the acoustic driver 110 may be close to the ear canal but not block the ear canal, so that the user's ear 101 is kept in an open state and the user can hear not only the sound output from the open-type earphone 100 but also the sound of the external environment. For example, the open-type earphone 100 may be installed around or partially around the user's ear 101, and may transmit sound by air conduction or bone conduction.

[0042] In some embodiments, the housing 120 may be worn on the user's body and may house the acoustic driver 110. In some embodiments, the housing 120 may be a hollow sealed housing structure, and the acoustic driver 110 is located inside the housing 120. In some embodiments, the open-type earphone 100 may be combined with a product such as glasses, headphones, a head-mounted display, or an AR / VR helmet, in which case the housing 120 may be fixed near the user's ear 101 in a hanging or clamping manner. In some alternative embodiments, a hanging structure (e.g., a hook) may be provided on the housing 120. For example, the shape of the hook may be adapted to the shape of the pinna, and the open-type earphone 100 may be independently worn on the user's ear 101 through the hook.

[0043] In some embodiments, the housing 120 may be a housing structure having a shape that fits the human ear 101, such as a ring shape, an ellipse shape, a (regular or irregular) polygonal shape, a U-shape, a V-shape, a semicircular shape, etc., so that the housing 120 can be directly hung on the user's ear 101. In some embodiments, the housing 120 may further include a fixing structure. The fixing structure may include an ear hook, an elastic band, etc., so that the open-type earphone 100 can be better fixed to the user and prevented from falling off during use by the user.

[0044] In some embodiments, when a user wears the open-type earphone 100, the housing 120 may be located above, below, in front of the user's ear 101 (e.g., in front of the tragus) or in the auricle (e.g., in the cavity of the concha). The housing 120 may further be formed with two or more sound emission holes for transmitting sound. In some embodiments, the acoustic driver 110 may output sound having a phase difference (e.g., opposite phase) through the two sound emission holes.

[0045] The acoustic driver 110 is a component that can receive an electric signal, convert it into an audio signal, and output it. In some embodiments, when distinguished according to frequency, the type of the acoustic driver 110 may include a low frequency (e.g., 30Hz-150Hz) speaker, a mid-low frequency (e.g., 150Hz-500Hz) speaker, a mid-high frequency (e.g., 500Hz-5kHz) speaker, a high frequency (e.g., 5kHz-16kHz) speaker, or a wideband (e.g., 30Hz-16kHz) speaker, or any combination thereof. Here, the low frequency, high frequency, etc., only represent a rough range of frequency, and different application scenes may have different division methods. For example, a crossover frequency is determined, and the low frequency represents the frequency range below the crossover frequency, and the high frequency represents the frequency range above the crossover frequency. The crossover frequency may be any value within the audible range of the human ear, such as 500Hz, 600Hz, 700Hz, 800Hz, 1000Hz, etc.

[0046] In some embodiments, a core and a motherboard (not shown) may be further installed inside the housing 120. The core may constitute at least a part of the structure of the acoustic driver 110, and the acoustic driver 110 may generate sounds by the core, which are transmitted to corresponding sound emitting holes along corresponding acoustic paths, respectively, and output from the sound emitting holes. The motherboard may be electrically connected to the core to control the sound output of the core. In some embodiments, the motherboard may be installed in a position close to the core of the housing 120 to shorten the wiring distance between the core and other components (e.g., function buttons).

[0047] In some embodiments, the acoustic driver 110 may include one diaphragm. When the diaphragm vibrates, sound is emitted from the front and rear sides of the diaphragm, respectively. In some embodiments, a front cavity (not shown) for transmitting sound is provided at a position in front of the diaphragm in the housing 120. The front cavity is acoustically coupled to one of the sound emission holes (e.g., the first sound emission hole), and sound from the front side of the diaphragm can be emitted from the first sound emission hole via the front cavity. A rear cavity (not shown) for transmitting sound is provided at a position in the rear of the diaphragm in the housing 120. The rear cavity is acoustically coupled to another sound emission hole (e.g., the second sound emission hole), and sound from the rear side of the diaphragm can be emitted from the second sound emission hole via the rear cavity. In some embodiments, the core may include a core housing (not shown), and the core housing and the diaphragm of the acoustic driver 110 define and form a front cavity and a rear cavity of the acoustic driver 110. In some embodiments, the open-type earphone 100 may further include a power source (not shown). The power source may be located at any position of the open-type earphone 100, for example, at a position of the housing 120 away from the acoustic driver 110 or at a position close to the acoustic driver 110. In some embodiments, the position of the power source may be set reasonably according to the weight distribution situation of the open-type earphone 100, thereby making the weight distribution of the open-type earphone 100 uniform and improving the comfort and stability of the user wearing the open-type earphone 100. In some embodiments, the power source may provide power to individual components of the open-type earphone 100 (e.g., the acoustic driver 110, the core, etc.). The power source may be electrically connected to the acoustic driver 110 and / or the core to provide power thereto. When the diaphragm is vibrating, a pair of sounds with a phase difference (e.g., opposite phases) can be generated simultaneously on the front and rear sides of the diaphragm. After passing through the front and rear cavities, respectively, the sounds are propagated outward from the positions of the first and second sound emission holes.In some embodiments, the structure of the front cavity and the rear cavity may be set so that the sound output from the first sound output hole and the second sound output hole of the acoustic driver 110 meets a certain condition. For example, by designing the length of the front cavity and the rear cavity, a pair of sounds having a specific phase relationship (e.g., opposite phase) can be output from the first sound output hole and the second sound output hole, so that the near-field listening volume of the open-type earphone 100 can be reduced and the far-field sound leakage problem can be effectively improved.

[0048] In order to further explain the influence of the sound output effect of an open-type earphone due to the sound emission holes distributed on both sides of the pinna, in this specification, the open-type earphone and the pinna are equivalent to a dual point source-baffle model.

[0049] For convenience of explanation, when the dimensions of the sound emission holes of an open-type earphone are small, each sound emission hole can be approximately regarded as one point sound source. The sound field sound pressure p generated by a single point sound source satisfies formula (1).

[0050]

number

[0051] In the formula, ω is the angular frequency, ρ0 is the air density, r is the distance between the target point and the sound source, Q0 is the volume velocity of the sound source, and k is the wave number. The magnitude of the sound field sound pressure of a point sound source is inversely proportional to the distance to the point sound source.

[0052] As described above, by providing two sound emission holes (e.g., a first sound emission hole and a second sound emission hole) in the open-type earphone 100 to form a dipole sound source, the sound emitted by the open-type earphone to the surrounding environment (i.e., sound leakage in the far field) can be reduced. In some embodiments, the sound output from the two sound emission holes, i.e., the dipole sound source, has a certain phase difference. When the position, phase difference, etc. between the dipole sound sources meet certain conditions, the open-type earphone can achieve different sound effects in the near field and the far field. For example, when the phases of the point sound sources corresponding to the two sound emission holes are opposite, i.e., the absolute value of the phase difference between the two point sound sources is 180°, according to the principle that sound waves are offset if their phases are opposite, a reduction in sound leakage in the far field can be realized. Also, for example, when the phases of the point sound sources corresponding to the two sound emission holes are almost opposite, a reduction in sound leakage in the far field can be realized. By way of example only, the absolute value of the phase difference between two point sound sources that achieves reduced far-field sound leakage may be in the range of 120° to 240°.

[0053] FIG. 2 is a schematic diagram of two point sound sources in accordance with some embodiments of the present disclosure.

[0054] As shown in FIG. 2, the sound field pressure p generated by a dipole sound source satisfies the following formula:

[0055]

number

[0056] In the formula, A1 and A2 are the intensities of the two point sound sources, respectively, φ1 and φ2 are the phases of the point sound sources, d is the distance between the two point sound sources, and r1 and r2 satisfy formula (3).

[0057]

number

[0058] In the formula, r is the distance between an arbitrary target point in space and the center position of the dipole sound source, and θ is the included angle between the line connecting the target point and the center of the dipole sound source and the straight line on which the dipole sound source is located.

[0059] As can be seen from equation (3), the magnitude of the sound pressure p at a target point in a sound field is related to the intensity, spacing d, phase, and distance to each point sound source.

[0060] In the application of open-type earphones, it is necessary to ensure that the sound pressure transmitted to the listening position is large enough to meet the listening needs, and at the same time, ensure that the sound pressure radiated to the far field is small enough to reduce sound leakage. Therefore, the sound leakage index α can be used as an index to evaluate the sound leakage reduction ability.

[0061]

number

[0062] In the formula, P far represents the sound pressure in the far field of an open-type earphone (i.e., the sound leakage pressure in the far field), and P ear represents the sound pressure around the user's ear (i.e., near-field listening sound pressure). As can be seen from equation (4), the smaller the sound leakage index, the higher the sound leakage reduction capability of the open-type earphone, and the smaller the sound leakage in the far field when the near-field listening volume at the listening position is the same.

[0063] FIG. 3 is a schematic diagram of a case where sound leakage is measured according to some embodiments of the present specification. As shown in FIG. 3, the listening position is located to the left of the point sound source A1, and the measuring method of the sound leakage is to select the center of the dipole sound source (A1 and A2 shown in FIG. 3) as the center of a circle, and the average value of the sound pressure amplitude of each point on a sphere with a radius of r as the value of the sound leakage. It should be noted that the measuring method of the sound leakage in this specification is merely an illustrative explanation of the principle and effect, and is not limited, and the measuring method and the calculation method of the sound leakage may be reasonably adjusted according to the actual situation. For example, the center of the dipole sound source is the center of a circle, and the sound pressure amplitudes of two or more points are evenly selected and averaged based on a certain spatial angle in the far field. In some embodiments, the measuring method of the sound leakage may be to select one position point near the point sound source as the listening position, and the sound pressure amplitude measured at the listening position as the value of the sound leakage. In some embodiments, the listening position may be on the line connecting the two point sound sources, or may not be on the line connecting the two point sound sources. The measurement and calculation methods of the listening sound may be reasonably adjusted according to the actual situation, for example, averaging the sound pressure amplitudes of other points or one or more points in the near-field position, for example, taking a point sound source as the center of a circle, and equally selecting and averaging the sound pressure amplitudes of two or more points in the near field according to a certain spatial angle. In some embodiments, the distance between the near-field listening position and the point sound source is much smaller than the distance between the point sound source and the sound leakage measurement sphere in the far field.

[0064] FIG. 4 is a comparison diagram of the sound leakage index at different frequencies of a single point sound source and a dual point sound source according to some embodiments of the present specification. The dual point sound source (also called a dipole sound source) in FIG. 4 may be a typical dual point sound source, that is, the interval is constant, the amplitude of the two point sound sources is the same, and the phase of the two point sound sources is opposite. It should be noted that the typical dual point sound source is selected to only describe the principle and effect, and the parameters of each point sound source can be adjusted according to actual needs to have a certain difference from the typical dual point sound source. As shown in FIG. 4, when the interval is constant, the sound leakage generated by the dual point sound source increases with the increase of frequency, and the sound leakage reduction ability becomes weaker with the increase of frequency. When the frequency is greater than a certain frequency value (for example, about 8000Hz as shown in FIG. 4), the generated sound leakage sound is greater than that of a single point sound source, and this frequency (for example, 8000Hz) is the upper limit frequency at which the dual point sound source can reduce sound leakage.

[0065] In order to adjust the output effect of the dual point sound sources (e.g., reduce the sound leakage index), the distance d between the dual point sound sources can be adjusted. FIG. 5 is a frequency response characteristic curve at the near-field listening position of dipole sound sources with different distances according to some embodiments of the present specification. As shown in FIG. 5, as the distance between the point sound source A1 and the point sound source A2 gradually increases (e.g., increases from d to 10d), the sound volume at the listening position gradually increases. The reason is that as the distance between the point sound source A1 and the point sound source A2 increases, the sound of the two paths reaching the listening position has a larger amplitude difference (i.e., sound pressure difference) and a larger difference in acoustic distance, so the sound cancellation effect is lowered and the sound volume at the listening position further increases. However, since sound cancellation still exists, the sound volume at the listening position is still smaller than the sound volume generated by a single point sound source of the same intensity at the same position in the mid-low frequency band (e.g., sound with a frequency lower than 1000 Hz). In the high frequency band (e.g., sounds close to 10,000 Hz), the wavelength of the sound becomes smaller, so that the condition for satisfying sound multiplication appears, and the sound generated by a dipole sound source becomes louder than the sound generated by a single point sound source. In the embodiment of the present specification, the sound pressure amplitude, i.e., the sound pressure, may be the pressure of the sound due to the vibration of the air.

[0066] In some embodiments, the distance between the dipole sound sources can be increased to increase the volume at the listening position, but as the distance increases, the canceling ability of the dipole sound sources becomes weaker, which further causes an increase in sound leakage in the far field. For illustration purposes only, FIG. 6 is a schematic diagram of two point sound sources and listening positions according to some embodiments herein. FIG. 7 is a diagram showing the sound leakage index in the far field of dipole sound sources with different spacing according to some embodiments herein. Based on the listening positions shown in FIG. 6, the point sound source A1 and the point sound source A2 are located on the same side of the listening position, the point sound source A1 is closer to the listening position, and the point sound source A1 and the point sound source A2 respectively output sounds with the same amplitude but opposite phase. The method of measuring the sound leakage is to select the average value of the sound pressure amplitude of each point on the spherical surface with the center of the double point sound source as the center of the circle and the radius of the sphere being 50 cm as the value of sound leakage, and calculate the sound leakage index in the far field of the single point sound source and the dipole sound sources with different spacing. As shown in Figure 7, taking the far-field sound leakage index of a single point sound source as a reference, as the distance between the dipole sound sources increases from d to 10d, the far-field sound leakage index gradually increases, which indicates that the sound leakage gradually increases. At the same time, for a single point sound source, the frequency band that can reduce sound leakage gradually narrows. Note that the above-mentioned method for measuring sound leakage is selected here only to explain the principle and effect.

[0067] In some embodiments, a baffle may be installed around one of the dual point sound sources to improve the output effect of the open-type earphone, i.e., to increase the sound intensity at the near-field listening position while simultaneously reducing the volume of sound leakage in the far field. Figure 8 is an exemplary distribution schematic diagram when a baffle is installed around one of the dipole sound sources according to some embodiments of the present specification. As shown in Figure 8, when a baffle is installed between the point sound source A1 and the point sound source A2, in the near field, the sound field of the point sound source A2 can only interfere with the sound wave of the point sound source A1 at the listening position by bypassing the baffle, which corresponds to an increase in the acoustic distance from the point sound source A2 to the listening position. Therefore, assuming that the point sound source A1 and the point sound source A2 have the same amplitude, the amplitude difference of the sound waves at the listening position between the point sound source A1 and the point sound source A2 increases compared to when the baffle is not installed, thereby decreasing the degree to which the sounds of the two paths are offset at the listening position, and increasing the volume at the listening position. In the far field, the sound waves generated by the point sound source A1 and the point sound source A2 can interfere in a wide spatial range without going around the baffle (similar to the case where there is no baffle), so the sound leakage in the far field does not increase obviously compared to the case where there is no baffle. Therefore, by installing a baffle structure around one of the point sound sources A1 and A2, the sound volume at the near field listening position can be significantly increased while the sound leakage volume in the far field does not increase significantly.

[0068] 9 is a diagram showing the sound leakage index when a baffle is installed around one of the dipole sound sources and when no baffle is installed according to some embodiments of the present specification. After adding a baffle to the double point sound source, in the near field, it corresponds to increasing the distance between the two point sound sources, the sound volume at the near field listening position corresponds to that generated by the double point sound source with a large distance, and the sound volume of the near field listening position is obviously increased compared to the case without a baffle, and in the far field, the sound field of the two point sound sources is less affected by the baffle, and the sound leakage generated corresponds to that generated by the double point sound source with a small distance. Therefore, as shown in FIG. 9, after adding the baffle, the sound leakage index is significantly smaller than that without the baffle, that is, at the same listening volume, the sound leakage in the far field is smaller than that without the baffle, and the sound leakage reduction ability is obviously stronger.

[0069] In some embodiments, on the premise of maintaining a constant distance between the dipole sound sources, with respect to the positions of the dipole sound sources, the listening positions have a certain influence on the near-field listening volume and the reduction of sound leakage in the far field. In order to improve the output effect of the open-type earphone, in some embodiments, two sound emission holes may be provided in the open-type earphone. When the user wears the earphone, the two sound emission holes are respectively located on both sides of the front and rear of the baffle. Considering that in some embodiments, it is necessary for the sound emitted from the sound emission hole located on the rear side of the baffle to bypass the baffle to reach the user's external auditory canal, the acoustic path from the sound emission hole located on the front side of the baffle to the user's external auditory canal (i.e., the acoustic distance from the sound emission hole to the entrance of the user's external ear) is shorter than the acoustic path from the sound emission hole located on the rear side of the baffle to the user's ear. To further explain the influence of the listening position on the sound output effect, for illustrative purposes, in the embodiments of this specification, FIG. 10 is a schematic diagram of a dipole sound source with a baffle at different listening positions in the near field according to some embodiments of this specification. As shown in FIG. 10, four representative listening positions (listening position 1, listening position 2, listening position 3, listening position 4) are selected to explain the effects and principles resulting from the selection of the listening positions. The listening positions 1, 2, and 3 are equidistant from the point sound source A1 and the distance is r1. The distance between the listening position 4 and the point sound source A1 is r2, where r2 < r1. The point sound source A1 and the point sound source A2 generate sounds with opposite phases respectively.

[0070] FIG. 11 is a frequency response characteristic curve diagram when a dipole sound source with a baffle is at different listening positions (shown in FIG. 10) in the near field according to some embodiments of the present specification. As shown in FIG. 11, when there is a baffle, the sound leakage volume in the far field does not change with the change of listening position. The listening volume at listening position 1 exceeds the listening volume at listening position 2 and listening position 3. At listening position 4, the listening volume at listening position 4 is still the largest among the four listening positions selected, because the distance between the listening position and the point sound source A1 is small and the sound field amplitude at the position of the point sound source A1 is large. Because the sound leakage volume in the far field does not change with the change of listening position and the listening volume at the near field listening position changes with the change of listening position, the sound leakage index of the open-type earphone is different at different listening positions, as shown in FIG. 11. At listening positions where the listening volume is high (e.g., listening positions 1 and 4), the sound leakage index is small and the sound leakage reduction capability is high, whereas at listening positions where the listening volume is low (e.g., listening positions 2 and 3), the sound leakage index is large and the sound leakage reduction capability is low.

[0071] In order to increase the listening volume, especially the listening volume of the mid-low frequency, while still maintaining the effect of canceling the sound leakage in the far field, a cavity structure may be installed around one of the dual point sound sources. FIG. 12 is an exemplary distribution schematic diagram when a cavity structure is installed around one of the dipole sound sources according to some embodiments of the present specification. The "cavity structure" in the present specification is a structure that is isolated from the outside and has a hollow inside, and the structure does not completely seal and block the inside and the outside, but has a leak structure (e.g., an opening, a gap, a duct, etc.) that acoustically communicates with the outside environment, forming a structure similar to a cavity and ensuring the property of opening both ears. In some embodiments, the cavity structure may be installed with a leak structure that can acoustically communicate the inside of the cavity structure with the outside environment and ensure the opening of both ears. The exemplary leak structure may include an opening, a gap, a duct, etc., or any combination thereof.

[0072] In some embodiments, the cavity structure may include a listening position and at least one sound source. "Include" here may mean that at least one of the listening position and the sound source is inside the cavity, or at least one of the listening position and the sound source is located at the edge of the inside of the cavity. In some embodiments, the listening position may be the ear, the ear canal opening of the ear, an acoustic reference point of the ear, such as an ERP, DRP, etc., an entrance structure that guides the listener, etc.

[0073] The two sound sources with opposite phases constitute a dipole, which respectively radiates sound into the surrounding space, generating the phenomenon of sound wave interference cancellation, and achieving the sound leakage cancellation effect. Since the difference in acoustic distance and volume between the two sounds is large at the listening position, the sound cancellation effect is relatively insignificant, and the sound can be heard louder at the listening position than at other positions. In order to ensure the sound leakage cancellation effect and at the same time maximize the listening volume, a cavity structure as shown in FIG. 12 may be installed. As shown in FIG. 12, when a cavity structure is installed between the dipole sound sources, one of the dipole sound sources and the listening position are inside the cavity structure, and the other dipole sound source is outside the cavity structure.

[0074] 13 is a schematic diagram of a dipole source structure and the principle when a cavity structure is placed around one of the dipole sources, according to some embodiments herein.

[0075] In the dipole sound source structure shown in Figure 13, two sound sources with opposite phases form a dipole, which respectively radiates sound into the surrounding space, generating the phenomenon of sound wave interference cancellation, and achieving the effect of sound leakage cancellation. Because the difference in acoustic distance between the two sounds is large at the listening position, the sound cancellation effect is relatively less prominent, and the sound can be heard louder at the listening position than at other positions.

[0076] In order to ensure the sound leakage cancellation effect and at the same time increase the listening volume as much as possible, a cavity structure as shown in FIG. 12 may be installed around one of the two dipole sound sources. For listening, as shown in the upper right of FIG. 13, one of the sound sources A is surrounded by a cavity structure, so most of the radiated sound reaches the listening position by direct or reflected light. In contrast, if there is no cavity structure, most of the sound radiated from the sound source does not reach the listening position. Therefore, by installing the cavity structure, the sound volume reaching the listening position can be significantly increased. At the same time, only a small part of the anti-phase sound radiated from the anti-phase sound source B outside the cavity structure enters the cavity structure through the leakage structure of the cavity structure. This corresponds to the generation of a secondary sound source B' in the leakage structure, whose intensity is significantly smaller than that of the sound source B and significantly smaller than that of the sound source A. The sound generated by the secondary sound source B' has a weak anti-phase cancellation effect on the sound source A in the cavity, which significantly increases the sound volume at the listening position.

[0077] Regarding sound leakage, as shown in the lower right of Fig. 13, sound source A radiating sound to the outside through the leaking structure of the cavity is equivalent to secondary sound source A' being generated in the leaking structure, and since almost all of the sound radiated from sound source A is output from the leaking structure and the structural scale of the cavity is much smaller (at least one order of magnitude smaller) than the spatial scale for evaluating sound leakage, the strength of secondary sound source A' is considered to be equivalent to sound source A. The sound cancellation effect generated by secondary sound source A' and sound source B in the external space is equivalent to the sound cancellation effect generated by sound source A and sound source B. In other words, the cavity structure still maintains a considerable sound leakage reduction effect.

[0078] FIG. 14A is a schematic diagram of a monopole sound source according to some embodiments herein. FIG. 14B is a schematic diagram of a dipole sound source according to some embodiments herein. FIG. 14C is a schematic diagram of a baffle structure installed around one of the dipole sound sources according to some embodiments herein. FIG. 14D is a schematic diagram of a cavity structure installed around one of the dipole sound sources according to some embodiments herein. FIG. 15A is a frequency response characteristic curve diagram of listening sound and sound leakage at a listening position of a monopole sound source according to some embodiments herein. FIG. 15B is a frequency response characteristic curve diagram of listening sound and sound leakage at a listening position of a dipole sound source according to some embodiments herein. FIG. 15C is a frequency response characteristic curve diagram of listening sound and sound leakage at a listening position of a dipole sound source according to some embodiments herein. FIG. 15D is a frequency response characteristic curve diagram of listening sound and sound leakage at a listening position when a cavity structure is installed around one of the dipole sound sources in accordance with some embodiments of the present disclosure.

[0079] Generally, the greater the difference between the frequency response curve of the sound volume and the frequency response curve of the sound leakage volume, the better. As can be seen from Figures 15A to 15D, the scheme using the cavity structure has a significantly improved sound volume compared to other structures, while the sound leakage volume is equivalent to other structures. This indicates that when the cavity structure is used, the sound leakage is the smallest at the same sound volume, and the sound volume is the largest at the same sound leakage volume.

[0080] In order to express the effect of the scheme more directly, the reciprocal 1 / α of the sound leakage index α, which may be called the hearing index, may be used as the effect of evaluating each structure. It means the magnitude of the sound volume when the sound leakage is the same. From the viewpoint of application, the larger the hearing index, the better. FIG. 16 is a schematic diagram of the hearing index when a baffle structure is installed around one of a monopole sound source, a dipole sound source, and a dipole sound source, and when a cavity structure is installed around one of the dipole sound sources, according to some embodiments of the present specification. As shown in FIG. 16, from the viewpoint of the hearing index, the cavity structure can significantly increase the sound volume, and therefore its hearing effect is significantly better than other structures.

[0081] In some embodiments, the hearing effect is related to leaking structures (eg, openings, gaps, conduits, etc.) in the cavity structure, and the location of the leaking structures and the size of the openings are described below.

[0082] FIG. 17 is a schematic diagram of a cavity structure according to some embodiments of the present specification. As shown in FIG. 17, the opening area of ​​the leaking structure in the cavity structure is S, and the area on which the sound source included in the cavity structure acts directly is S0. Here, "acting directly" means that the sound emitted from the included sound source acts acoustically directly on the wall surface of the cavity structure without passing through the leaking structure. The distance between the two sound sources is d0, and the distance from the center of the opening shape of the leaking structure (abbreviated as the centroid) to the other sound source is L.

[0083] Fig. 18 is a hearing index curve diagram of cavity structures with different sizes of leakage structures according to some embodiments of the present specification. As shown in Fig. 18, the relative distance from the opening to the centroid is kept constant (e.g., L / d0=1.09), and the larger the relative opening size S / S0 is, the smaller the hearing index becomes. This is because the larger the relative opening is, the more sound components are directly radiated outward from the contained sound source, and the less sound reaches the listening position, so the listening volume decreases with the increase in the relative opening, which leads to a smaller listening index.

[0084] Fig. 19 is a curve diagram of the hearing index of cavity structures with different positions of leakage structures according to some embodiments of the present specification. As shown in Fig. 19, when the relative opening size (e.g., S / S0=0.06) is kept constant, the hearing index decreases as the relative distance L / d0 from the opening to the centroid increases. This is because the greater the relative distance, the greater the distance between the secondary sound source A' and the sound source B generated at the opening, which weakens the anti-phase cancellation effect of the sounds generated by both in the external sound field, which increases sound leakage, and ultimately leads to a decrease in the hearing index.

[0085] FIG. 20A is a hearing index curve diagram of a cavity structure having a leak structure of different positions and different sizes at a frequency of 500 Hz, according to some embodiments herein; FIG. 20B is a hearing index curve diagram of a cavity structure having a leak structure of different positions and different sizes at a frequency of 1000 Hz, according to some embodiments herein; FIG. 20C is a hearing index curve diagram of a cavity structure having a leak structure of different positions and different sizes at a frequency of 2000 Hz, according to some embodiments herein; and FIG. 20D is a hearing index curve diagram of a cavity structure having a leak structure of different positions and different sizes at a frequency of 5000 Hz, according to some embodiments herein. Taking into consideration the relative area S / S0 of the opening of the leaking structure and the relative distance L / d0 from the centroid of the opening to the external sound source in a comprehensive manner, in some embodiments, in order to ensure that the hearing index is higher than that of a dipole in all major frequency bands of hearing (e.g., frequency bands below 5000 Hz or 10 kHz), the relative area S / S0 of the opening of the leaking structure may be set to 0.8 or less, while the relative distance L / d0 from the centroid of the opening to the external sound source may be set to 1.7 or less.

[0086] It should be noted that the above-mentioned leakage structure with one opening is merely an example, and the leakage structure of the cavity structure can include one or more openings, which can realize an excellent hearing index, and can especially improve the hearing index of high frequencies. Taking a structure with two openings as an example, the following will analyze the cases of equal openings and equal opening ratios. The structure with only one opening is compared, and "equal openings" here means that two openings of the same size are installed as in the structure with only one opening, and "equal opening ratio" means that the sum S / S0 of the opening areas of the two installed holes is the same as in the structure with only one hole. The equal openings are equivalent to the relative opening size S / S0 of the structure with only one hole being enlarged by a factor of 1, and as mentioned above, the overall hearing index is reduced. In the case of equal opening ratios, even if S / S0 is the same as in the structure with only one hole, the distances from the two openings to the external sound source are different, resulting in different hearing indexes.

[0087] In some embodiments, when the line connecting the two openings forms different included angles with respect to the line connecting the two sound sources, it will result in differences in the positions of the secondary sound sources formed at the openings, and further affect the sound leakage reduction effect. FIG. 21A is a schematic diagram of a cavity structure having two horizontal openings according to some embodiments herein. FIG. 21B is a schematic diagram of a cavity structure having two vertical openings according to some embodiments herein. As shown in FIG. 21A, when the line connecting the two openings is parallel to the line connecting the two sound sources (i.e., two horizontal openings), the distances from the two openings to the external sound source are maximum and minimum, respectively, and as shown in FIG. 21B, when the two connecting lines are perpendicular (i.e., two vertical openings), the distances from the two openings to the external sound source are equal and take an intermediate value.

[0088] FIG. 22 is a comparison diagram of the hearing index curves of a cavity structure having two openings and a cavity structure having one opening according to some embodiments of the present disclosure. As shown in FIG. 22, the cavity structure with equal openings has a lower hearing index overall than the cavity structure with one opening. For the cavity structure with equal opening ratio, the distances from the two openings to the external sound source are different, resulting in different hearing indexes. As shown in FIG. 21A, FIG. 21B, and FIG. 22, the hearing index of the leakage structure with equal opening ratio is higher than that of the leakage structure with equal opening ratio, whether it is a horizontal opening or a vertical opening. This is because the relative opening size S / S0 of the leakage structure with equal opening ratio is reduced by 1 times compared to the leakage structure with equal opening ratio, resulting in a higher hearing index. As shown in FIG. 21A, FIG. 21B, and FIG. 22, the hearing index of the leakage structure with equal opening ratio is higher than that of the leakage structure with equal opening ratio, whether it is a horizontal opening or a vertical opening. This is because in the leakage structure of the horizontal openings, the distance from one of the openings to the external sound source is smaller than the distance between the two sound sources, and the distance between the secondary sound source thus formed and the external sound source is closer than the original two sound sources, so that the hearing index is higher and the sound leakage reduction effect is further improved. Therefore, in order to improve the sound leakage reduction effect, the distance from at least one opening to the external sound source may be made smaller than the distance between the two sound sources.

[0089] Fig. 23A is a schematic diagram of a cavity structure having one opening, Fig. 23B is a schematic diagram of a cavity structure having two openings, Fig. 23C is a schematic diagram of a cavity structure having three openings, Fig. 23D is a schematic diagram of a cavity structure having four openings, according to some embodiments of the present disclosure.

[0090] FIG. 24 is a comparison diagram of hearing index curves of cavity structures with different numbers of openings according to some embodiments of the present specification. As shown in FIG. 24, a cavity structure using multiple openings can better improve the resonant frequency of the air sound in the cavity structure compared to a cavity structure with one opening, so that the whole device has a better hearing index in the high frequency band (e.g., sound with a frequency close to 10000Hz) compared to a cavity structure with only one opening. The high frequency band is a frequency band where human ears are more sensitive, so there is a greater need for sound leakage reduction. Therefore, a cavity structure with a number of openings greater than 1 may be selected to improve the sound leakage reduction effect in the high frequency band.

[0091] In some embodiments, the acoustic effect is related to the cavity volume in the cavity structure, and the following describes the influence of the cavity volume on the acoustic effect. FIG. 25A is a schematic diagram of a cavity structure with one opening according to some embodiments herein. As shown in FIG. 25A, the cavity volume of the cavity structure is V, the distance from the opening to the external sound source is d0, the reference volume is V0=d0*d0, and the relative volume of the cavity structure is V / V0. Note that FIG. 25A is studied and simulated in a 2D scale, so the concept of volume is the square of length, and accordingly, when analyzing in a 3D scale, the change of volume should be corrected to the cube of length.

[0092] FIG. 25B is a comparison diagram of the hearing index curves at different relative volumes of a cavity structure with one opening according to some embodiments of the present specification. As shown in FIG. 25B, for a double point sound source (dipole) without a cavity structure, the larger the relative volume V / V0 of the cavity structure, the larger the hearing index in the low frequency band (e.g., frequency is 500 Hz or less) and the smaller the hearing index in the high frequency band (e.g., frequency is 500 Hz or more). Overall, the larger the relative volume V / V0 of the cavity structure, the smaller the hearing index overall. This is because, due to the influence of the air-sound resonance in the cavity structure, air-sound is generated in the cavity structure at the resonant frequency of the cavity structure, which radiates a sound far louder than the external sound source outward, resulting in a significant improvement in sound leakage, and furthermore, the hearing index is significantly smaller around the resonant frequency. As shown in FIG. 25B, the hearing index is significantly smaller around the resonant frequency, which appears as a deep dip on the frequency response curve. When the size of the opening is unchanged, the larger the relative volume of the cavity structure, the lower the resonant frequency and the deeper the dip formed. As shown in FIG. 25B, in order to reduce the effect of the dip in the hearing index and make the hearing index of most frequency bands higher than that of the dipole sound source without the cavity structure, the relative volume V / V0 of the cavity structure is set so that its resonant frequency is shifted to as high a frequency as possible and meets a certain condition, for example, the condition of 7000Hz or more. In this situation, the relative volume V / V0 of the cavity structure may be 1.75 or less. For example, the relative volume V / V0 of the cavity structure may be 1.7 or less.

[0093] In some embodiments, the hearing and sound leakage effects are related to the magnitude of the sound source volume. FIG. 26A is a schematic diagram of a cavity structure with one opening according to some embodiments of the present specification. As shown in FIG. 26A, the magnitude of the sound source volume is characterized by testing the effective values ​​PA and PB of the sound pressure generated by the two sound sources at positions having the same distance from the sound sources A and B, respectively, and the sound pressure ratio of the two sound sources is set as Nsource=PB / PA. Note that calibrating the magnitude of the sound source volume using the effective values ​​PA and PB of the sound pressure is just an example, and other methods may be used to calibrate the magnitude of the sound source volume.

[0094] Fig. 26B is a comparison diagram of the hearing index of cavity structures with different sound pressure ratio Nsource values ​​according to some embodiments of the present specification. As shown in Fig. 26B, when the relative opening size (e.g., S / S0=0.09) is kept unchanged and the Nsource value is small, the suppression of the internal sound of the cavity structure is insufficient, which causes the hearing volume in the cavity structure, especially the hearing volume of high frequency (e.g., above 5000Hz), to be large, resulting in the improvement of the hearing index of high frequency; in the low frequency band (e.g., below 1000Hz), the volume of sound source B is small, and it is difficult to form an ideal dipole sound field distribution, so the anti-phase cancellation effect on the sound leakage of sound source A is weak, the sound leakage is large, and the hearing index of low frequency is reduced.

[0095] When Nsource is close to 1, more sound from sound source B enters the cavity structure, weakening the sound volume, especially at high frequencies (e.g., above 5000 Hz), so that the high-frequency sound pressure index is lower than when the sound leakage is low relative to Nsource; in the mid-low frequency band (e.g., below 1000 Hz), sound source A and sound source B are closer to the ideal dipole sound field distribution, so the overall sound leakage is reduced, the sound pressure index is significantly improved, and the sound pressure index is ideal in the entire frequency band.

[0096] When Nsource is greater than 1, the sound leaking from sound source A is difficult to suppress in antiphase with the sound generated from sound source B, sound leakage in the internal space of the cavity structure increases, and the overall hearing index decreases. Only in the frequency band near the resonance frequency of the cavity structure (for example, about 2000 Hz), the hearing volume increases sharply due to air tone resonance, and the hearing index also increases sharply in that frequency band.

[0097] FIG. 27A is a hearing index curve diagram at a frequency of 20 Hz when the cavity structure shown in FIG. 26A has different sound pressure ratios Nsource with different leak structures of different sizes, according to some embodiments herein. FIG. 27B is a hearing index curve diagram at a frequency of 100 Hz when the cavity structure shown in FIG. 26A has different sound pressure ratios Nsource with different leak structures of different sizes, according to some embodiments herein. FIG. 27C is a hearing index curve diagram at a frequency of 1000 Hz when the cavity structure shown in FIG. 26A has different sound pressure ratios Nsource with different leak structures of different sizes, according to some embodiments herein. FIG. 27D is a hearing index curve diagram at a frequency of 10000 Hz when the cavity structure shown in FIG. 26A has different sound pressure ratios Nsource with different leak structures of different sizes, according to some embodiments herein.

[0098] FIG. 28A is a schematic diagram of a cavity structure with one opening, according to some embodiments herein. FIG. 28B is a hearing index curve diagram at a frequency of 20 Hz when the cavity structure shown in FIG. 28A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein. FIG. 28C is a hearing index curve diagram at a frequency of 100 Hz when the cavity structure shown in FIG. 28A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein. FIG. 28D is a hearing index curve diagram at a frequency of 1000 Hz when the cavity structure shown in FIG. 28A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein. FIG. 28E is a hearing index curve diagram at a frequency of 10000 Hz when the cavity structure shown in FIG. 28A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein.

[0099] FIG. 29A is a schematic diagram of a cavity structure with one opening, according to some embodiments herein. FIG. 29B is a hearing index curve diagram at a frequency of 20 Hz when the cavity structure shown in FIG. 29A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein. FIG. 29C is a hearing index curve diagram at a frequency of 100 Hz when the cavity structure shown in FIG. 29A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein. FIG. 29D is a hearing index curve diagram at a frequency of 1000 Hz when the cavity structure shown in FIG. 29A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein. FIG. 29E is a hearing index curve diagram at a frequency of 10000 Hz when the cavity structure shown in FIG. 29A has different leaking structures and different sound pressure ratios Nsource, according to some embodiments herein.

[0100] The difference between the cavity structures having one opening shown in Fig. 26A, Fig. 28A and Fig. 29A is that they have a relative distance L / d0 from the centroid of the opening to an external sound source. In Fig. 26A, the center of the cavity structure, the centroid of the opening of the leaking structure and the sound source located outside the cavity structure are on a straight line, and there is no shielding between the two sound sources, and the line connecting the center of the cavity structure and the centroid of the opening of the leaking structure in Fig. 28A is perpendicular to the line connecting the two sound sources, and in Fig. 29A, the center of the cavity structure, the centroid of the opening of the leaking structure and the sound source located outside the cavity structure are on a straight line, and the two sound sources are shielded via the cavity structure. As shown in Figures 27A to 27D, 28B to 28E, and 29B to 29E, in a situation where a dual point sound source in which a cavity structure is installed has a relative distance L / d0 from the centroid of a different opening to an external sound source, in order to ensure that both have a higher hearing index within the frequency range audible to the human ear than a dual point sound source structure in which a cavity structure is not installed, when the relative area S / S0 of the openings is 0.075 or less, the value of the sound pressure ratio Nsource of the two sound sources may be in the range of 0.2 to 2.0, when the relative area S / S0 of the openings is 0.25 or less, the value of the sound pressure ratio Nsource of the two sound sources may be in the range of 0.6 to 1.4, and when the relative area S / S0 of the openings is 0.45 or less, the value of the sound pressure ratio Nsource of the two sound sources may be in the range of 0.7 to 1.3.

[0101] In some embodiments, the loudness of the two sound sources may be adjusted by directly adjusting and controlling the magnitude of the output power of the two sound sources. In some embodiments, the difference in the sound volume of the two sound sources may be achieved by a specific acoustic structure of the sound sources. Exemplary acoustic structures may include slits, conduits, cavities, gauze, porous media, etc., or any combination thereof. For example, a conduit may be placed between one of the sound sources and the listening position to form a sound guide channel, thereby improving the sound volume at a specific frequency of the sound source. Also, for example, a porous medium may be placed between one of the sound sources and the listening position to reduce the sound volume of the sound source.

[0102] FIG. 30 is a block diagram of an exemplary open-type earphone 100 according to some embodiments of the present disclosure. As shown in FIG. 30, the open-type earphone 100 may include an acoustic driver 110, a housing 120, and a suspension structure 130. The acoustic driver 110 generates two sounds that are out of phase with each other. The housing 120 accommodates the acoustic driver 110. The suspension structure 130 fixes the housing 120 in a position near the user's ear and not blocking the user's ear canal. In some embodiments, the housing 120 may include a body 121 and a baffle 122. The body 121 defines a first cavity for accommodating the acoustic driver 110, and the baffle 122 is connected to the body 121 and extends toward the ear canal of the user to define a second cavity together with the pinna of the user (e.g., similar to the cavity structures shown in Figures 12, 13, 14D, 17, 21A-21B, 23A-23D, 25A, 26A, 28A, or 29A). For an explanation of the acoustic driver 110, the housing 120, and the suspension structure 130, reference may be made to Figure 1 or 31 of this specification.

[0103] Various embodiments of open-type earphones will be described below by way of example with reference to Figs.

[0104] FIG. 31 is a schematic diagram of an exemplary open-type earphone 100 according to some embodiments of the present disclosure. As shown in FIG. 31, the open-type earphone 100 may include an acoustic driver 110, a housing 120, and a suspension structure 130. The suspension structure 130 is connected to the housing 120 and fixes the housing 120 in a position near the user's ear 101 and not blocking the user's ear canal. For example, the housing 120 may be fixed to the front side of the user's tragus and closely contacted with a person's face. Also, for example, one end of the housing 120 (e.g., one end away from the suspension structure 130) may abut the inside of the user's pinna (e.g., in the cavity of the concha, above the antihelix, etc.). The acoustic driver 110 may generate two sounds that are out of phase. The housing 120 has a first cavity, and the acoustic driver 110 is installed in the first cavity. In some embodiments, the housing 120 may include a body 121 and a baffle 122. The body 121 may define a first cavity that accommodates the acoustic driver 110. In some embodiments, the body 121 may be a regular shape, such as a rectangle, a square, a cylinder, an elliptical cylinder, a sphere, or any other irregular shape. The baffle 122 may be connected to a side of the body 121 away from the user's face. For example, the baffle 122 may be connected to a surface of the body 121 that faces the face-contacting surface of the body 121 to avoid impacting the tragus of the ear. The baffle 122 may form a second cavity together with the user's pinna. In some embodiments, the housing 120 may be provided with a first sound emission hole 123 and a second sound emission hole 124 that communicate with the first cavity and respectively guide two sounds generated by the acoustic driver 110 in opposite phase. In some embodiments, according to the related description of FIG. 12, in order to increase the listening volume of the open-type earphone 100, especially the listening volume of the mid-low frequency, while still maintaining the effect of canceling the sound leakage in the far field, a second cavity is used to separate the two sound emission holes, so that one of the sound emission holes is located inside the second cavity and the other sound emission hole is located outside the second cavity.For example, as shown in FIG. 31, the first sound emission hole 123 is located inside the second cavity, and the second sound emission hole 124 is located outside the second cavity. For example, the first sound emission hole 123 may be located at a cross section (for example, as shown in FIG. 32) where the main body 121 and the baffle 122 intersect, and the second sound emission hole 124 may be located on any surface located outside the second cavity of the main body 121 (for example, a side familiar from a person's face as shown in FIG. 31, or a surface parallel to the side where the first sound emission hole 123 of the main body 121 is located). Note that the sound emission hole 123 cannot be seen from the angle shown in FIG. 31, and the number 123 indicates only the relative position between the plane where the first sound emission hole is located and the main body 121 and the baffle 122. In some embodiments, a sound emission hole located inside the second cavity (i.e., the first sound emission hole 123) may be located between the user's ear canal and a sound emission hole located outside the second cavity (i.e., the second sound emission hole 124).

[0105] In some embodiments, the first sound emission hole 123 may be located at a cross section (e.g., as shown in FIG. 32 ) where the main body 121 and the baffle 122 intersect, and the second sound emission hole 124 may be located on a side of the main body 121 away from the face, and the first sound emission hole 123 may be located closer to the user's ear canal than the second sound emission hole 124, so that the first sound emission hole 123 is located inside the second cavity and the second sound emission hole 124 is located outside the second cavity. In some embodiments, the first sound emission hole 123 may be located close to the baffle 122. If the baffle 122 is part of the main body 121, the first sound emission hole 123 may be located in the baffle 122. In some embodiments, the first sound emission hole 123 may be located between the user's ear canal and the second sound emission hole 124. In some embodiments, the first sound emitting hole 123 and the second sound emitting hole 124 may be distributed diagonally on the side surface facing the face of the main body 121. Note that the first sound emitting hole 123 and the second sound emitting hole 124 are not limited to being distributed diagonally as shown in Fig. 31, and may be distributed along the side of the main body 121 facing the face, or in any other distribution manner.

[0106] FIG. 32 is a schematic diagram of an example housing 120 according to some embodiments of the present disclosure. In some embodiments, the main body 121 may be located in front of the tragus or may be located in the pinna (there is an overlap between the main body 121 and the pinna projection surface), and the baffle 122 may be connected to the side of the main body 121 away from the user's face and extends toward the ear canal relative to the main body 121. In some embodiments, the baffle 122 may be a plate-like structure, and the thickness of the baffle 122 may be smaller than the thickness of the main body 121 because the main body 121 defines a first cavity that accommodates the acoustic driver 110. As shown in FIG. 32, the thickness t2 of the baffle 122 may be smaller than the thickness t1 of the main body 121. In some embodiments, when the body 121 is located in front of the tragus, the thickness of the body 121 may be the distance between the side of the body 121 close to the face and the side of the body 121 away from the face, and the thickness of the baffle 122 may be the distance between two sides parallel to the two sides of the body 121. In some embodiments, when the body 121 is located in the auricle or overlaps with the auricle projection plane, the thickness of the body 121 may be the distance between the side of the body 121 close to the auricle and the side of the body 121 away from the auricle, and the thickness of the baffle 122 may be the distance between two sides parallel to the two sides of the body 121. In some embodiments, the thickness of the body 121 may be the length of the body 121 along the coronal axis of the human body. The projection plane in this specification is the projection of the object on the head. For example, when the projection surface of the main body 121 overlaps with the auricle projection surface, it means that the projection surface of the main body 121 on the head overlaps with the projection surface of the auricle on the head, for example, the projection surface of the main body 121 is located completely within the range of the projection surface of the auricle.

[0107] 20A-20D and their related descriptions, in some embodiments, in order to improve the hearing index and make the hearing index at each frequency larger than that of a double-point (dipole) sound source without a cavity structure, the relative distance L / d0 from the centroid of the opening of the cavity structure to the sound source located outside the cavity structure may be 1.78 or less. As shown in FIG. 31, when a user wears the open-type earphone 100, the relative distance L / d0 from the centroid of the opening of the cavity structure to the sound source located outside the cavity structure may be expressed as a ratio of the distance L from the boundary 1221 (shown in FIG. 31) of the baffle 122 close to the user's ear canal to the second sound emission hole 124 to the distance d0 between the two sound emission holes. Here, the "distance from the boundary 1221 to the second sound emission hole 124" is the distance between the midpoint (e.g., midpoint M of the line segment m shown in FIG. 31) of the line connecting the two end points that abut against the pinna at the boundary or boundary surface of the baffle 122 close to the ear canal of the user (e.g., the midpoint M of the line segment m shown in FIG. 31) and the second sound emission hole 124. In some embodiments, the ratio of the distance from the boundary 1221 close to the ear canal of the user of the baffle 122 to the second sound emission hole 124 and the distance between the two sound emission holes may be less than 1.78. As a mere example, the ratio of the distance from the boundary 1221 close to the ear canal of the user of the baffle 122 to the second sound emission hole 124 and the distance between the two sound emission holes may be less than 1.78, 1.68, 1.58, 1.48, 1.38, 1.28, 1.18, or 1.08, etc.

[0108] In some embodiments, according to FIG. 22 and its related description, in order to make the distance between the secondary sound source located inside the cavity structure (i.e., the second cavity) and the sound source located outside the cavity structure (i.e., the second cavity) closer and improve the sound leakage reduction effect, the distance from the opening of the cavity structure to the external sound source may be smaller than the distance between the two sound sources. When the user wears the open-type earphone 100, the distance from the opening of the cavity structure (i.e., the second cavity) to the external sound source may be expressed as the distance from the boundary 1221 of the baffle 122 that is close to the user's ear canal to the second sound emission hole 124. In some embodiments, the distance from the boundary 1221 of the baffle 122 that is close to the user's ear canal to the second sound emission hole 124 may be smaller than the distance between the two sound emission holes (i.e., the first sound emission hole 123 and the second sound emission hole 124).

[0109] In some embodiments, according to Figs. 25A-25B and their related descriptions, in order to improve the overall hearing index, the relative volume V / V0 of the cavity structure (i.e., the second cavity) may be smaller than 1.75. The relative volume V / V0 of the cavity structure (i.e., the second cavity) may be expressed as a ratio between the volume of the second cavity and the reference volume. For example, the ratio between the volume of the second cavity and the reference volume may be smaller than 1.75. When the user wears the open-type earphone 100, the reference volume may be the cube of the distance from the boundary 1221 close to the user's ear canal to the sound emission hole (i.e., the second sound emission hole 124) located outside the second cavity. In some embodiments, the volume of the second cavity may be the volume of a sealed space surrounded by the concha cavity, the ear canal, the housing 120, the sound emission hole, and a curved surface surrounded by a gap that leaks sound. Therefore, the volume of the second cavity can be measured with a gel-injected mold for the ear. In some embodiments, the volume of the second cavity can be the product of the distance from the surface of the housing 120 facing the pinna / concha to the surface of the pinna / concha and the area enclosed by each contact point between the pinna and the housing 120. The distance from the surface of the housing 120 facing the pinna / concha to the surface of the pinna / concha may be the distance to the surface of the pinna / concha along the normal direction of a sound emission hole (e.g., the first sound emission hole 123) located inside the second cavity of the housing 120. Each contact point between the pinna and the housing 120 can include a contact point between the upper and lower edges of the housing 120 (e.g., two edges along the vertical axis of the human body) and the pinna, a contact point between an end of the housing 120 (e.g., one end away from the hanging structure 130) and the concha, an end point of the housing 120 closest to the wall of the concha, etc., or any combination thereof.

[0110] In some embodiments, according to Figures 27A-27D, 28B-28E, and 29B-29E and their related descriptions, in a situation where the dual point sound source in which the cavity structure (i.e., the second cavity) is installed has a relative distance L / d0 from the centroid of the different openings to the external sound source and a relative area S / S0 of the different openings, in a frequency range audible by the human ear, the value of the sound pressure ratio Nsource of the two sound sources may be in the range of 0.2 to 2.0 to ensure that the dual point sound source in which the cavity structure is not installed has a larger hearing index than the dual point sound source structure in which the cavity structure is not installed. For example, the ratio between the volume (or sound pressure) of the sound derived from the sound output hole (e.g., the second sound output hole 124) located outside the second cavity and the volume (or sound pressure) of the sound derived from the sound output hole located inside the second cavity (e.g., the first sound output hole 123) is in the range of 0.2 to 2.0. As a mere example, the range of the ratio between the volume of the sound guided from the second sound output hole 124 and the volume of the sound guided from the first sound output hole 123 may be 0.6 to 1.4. Also, for example, the range of the ratio between the volume of the sound guided from the second sound output hole 124 and the volume of the sound guided from the first sound output hole 123 may be 0.7 to 1.3.

[0111] In some embodiments, the volume of the sound radiated from the first sound radiating hole 123 and the second sound radiating hole 124 may be adjusted and controlled by adjusting and controlling the sound output power of the acoustic driver 110. In some embodiments, acoustic structures may be installed in the first cavity corresponding to the first sound radiating hole 123 and the second sound radiating hole 124, respectively, and two sounds output by the acoustic driver 110 that are out of phase with each other are radiated through the first sound radiating hole 123 and the second sound radiating hole 124 by the acoustic structures, respectively, and the acoustic structures can adjust the ratio between the volume of the sound radiated from the sound radiating hole located outside the second cavity (i.e., the second sound radiating hole 124) and the volume of the sound radiated from the sound radiating hole located inside the second cavity (i.e., the first sound radiating hole 123). Exemplary acoustic structures may include slits, conduits, cavities, gauze, porous media, etc., or any combination thereof.

[0112] In some embodiments, the hanging structure 130 may be an arc structure that conforms to the user's pinna so as to be suspended from the user's upper pinna. In some embodiments, the hanging structure 130 may be a clamping structure that conforms to the user's pinna so as to be clamped to the user's pinna. In some embodiments, the hanging structure 130 may have one end connected to the housing 120 away from the pinna and the other end extending along the user's pinna.

[0113] FIG. 33 is a schematic diagram of an exemplary housing 120 according to some embodiments of the present disclosure. As shown in FIG. 33, the main body 121 may be located in front of the tragus of the user, and the baffle 122 may be disposed to protrude from the main body 121 in the lateral direction or in the longitudinal direction. Here, the "lateral direction" is the direction along the sagittal axis of the human body, and the "longitudinal direction" is the direction along the vertical axis of the human body. The portion of the baffle 122 protruding from the main body 121 in the longitudinal direction has a longitudinal extension dimension (dimension a shown in FIG. 33), and the portion of the baffle 122 protruding from the main body 121 in the lateral direction has a lateral extension dimension (dimension b shown in FIG. 33).

[0114] FIG. 34A is a diagram showing a sound field of an open-type earphone without a baffle. FIG. 34B is a diagram showing a sound field of an open-type earphone with a baffle shown in FIG. 33. As shown in FIG. 34A, when the baffle 122 does not exist, the sound pressure is concentrated and distributed on the acoustic driver 110 (which can also be called the main body 121). As shown in FIG. 34B, when the baffle 122 exists, the baffle 122 may be approximated to a leaking structure in which the gap (for example, the gap 3401 shown in FIG. 34B) between the baffle 122 and the auricle (for example, the ear 101 shown in FIG. 34B) forms the second cavity. Since the sound A derived from the first sound emission hole 123 in the second cavity and the sound B derived from the second sound emission hole 124 outside the second cavity are in opposite phases, the sound A leaks through the leaking structure and is offset in opposite phase with the sound B, thereby ensuring the normal operation of the sound leakage reduction mechanism of the open-type earphone 100. At the same time, the existence of the second cavity can change the sound pressure distribution in the pinna, the sound pressure is concentrated and distributed on the baffle 122, and at least a part of the ear canal opening overlaps with the projection surface of the baffle 122, so that the sound pressure at the ear canal opening is greatly enhanced. Therefore, the existence of the second cavity can change the sound pressure distribution in the pinna, enhance the sound pressure at the ear canal opening, significantly increase the listening volume, and improve the hearing index.

[0115] FIG. 35 is a comparison diagram of the frequency response curves of an open-type earphone without a baffle and an open-type earphone with a baffle. As shown in FIG. 35, curve 351 represents the frequency response curve of the sound volume of the open-type earphone 100 when the baffle 122 is installed, and curve 352 represents the frequency response curve of the sound volume of the open-type earphone 100 when the baffle 122 is not installed. As can be seen from curves 351 and 352, the open-type earphone 100 with the baffle 122 installed has a significantly improved sound volume compared to when the baffle 122 is not installed. Curve 353 represents the frequency response curve of the sound leakage volume of the open-type earphone 100 when the baffle 122 is installed, and curve 354 represents the frequency response curve of the sound leakage volume of the open-type earphone 100 when the baffle 122 is not installed. As can be seen from the curves 353 and 354, the sound leakage volume of the open-type earphone 100 in which the baffle 122 is installed within the mid-low frequency range (for example, 100Hz to 600Hz) is lower than that in which the baffle 122 is not installed, indicating that the open-type earphone 100 with the baffle 122 has a high effect of reducing sound leakage within the mid-low frequency range. Fig. 36 is a curve diagram of the difference between the listening volume and the sound leakage volume of the open-type earphone without a baffle and the open-type earphone with a baffle. As shown in Fig. 36, the curve 355 represents the curve of the difference between the listening volume and the sound leakage volume of the open-type earphone 100 when the baffle 122 is installed, and the curve 355 represents the curve of the difference between the listening volume and the sound leakage volume of the open-type earphone 100 when the baffle 122 is not installed. According to the curves 355 and 356, the difference between the listening volume and the sound leakage volume of the open-type earphone 100 in which the baffle 122 is installed is larger in the low frequency band (for example, within 100 to 1000 Hz), and the listening effect and the sound leakage reduction effect are higher.

[0116] In some embodiments, the dimensions of the baffle 122 (e.g., the vertical and horizontal extension dimensions of the baffle 122 shown in FIG. 33) affect the dimensions of the second cavity and the relative opening size, so the listening volume and sound leakage volume of the open-type earphone 100 may be related to the vertical and horizontal extension dimensions of the baffle 122. FIG. 37A is a diagram showing the change in listening volume for different horizontal and vertical extension dimensions of the baffle 122 shown in FIG. 33 when the frequency is 500 Hz. FIG. 37B is a diagram showing the change in listening volume for different horizontal and vertical extension dimensions of the baffle 122 shown in FIG. 33 when the frequency is 1000 Hz. FIG. 37C is a diagram showing the change in sound leakage volume for different horizontal and vertical extension dimensions of the baffle 122 shown in FIG. 33 when the frequency is 500 Hz. FIG. 37D is a diagram showing the change in sound leakage volume in the horizontal and vertical extension dimensions of the baffle 122 shown in FIG. 33 when the frequency is 1000 Hz. As shown in FIG. 37A to FIG. 37D, when the horizontal extension dimension b of the baffle 122 varies within the range of 2 mm to 22 mm and the vertical extension dimension a varies within the range of 2 mm to 10 mm, the open-type earphone 100 improves the listening volume by up to about 8 dB and at the same time increases the sound leakage volume by up to about 3 dB, indicating that the hearing index of the open-type earphone 100 can always be improved when the horizontal extension dimension of the baffle 122 is within the range of 2 mm to 22 mm and the vertical extension dimension is within the range of 2 mm to 10 mm. Therefore, in some embodiments, the vertical extension dimension of the baffle 122 may be within the range of 2 mm to 10 mm. For example, the vertical extension dimension of the baffle 122 may be within the range of 3 mm to 9 mm. For example, the baffle 122 may have a longitudinal extension dimension in the range of 4 mm to 8 mm. In some embodiments, the baffle 122 may have a lateral extension dimension in the range of 2 mm to 22 mm. For example, the baffle 122 may have a lateral extension dimension in the range of 4 mm to 20 mm. For example, the baffle 122 may have a lateral extension dimension in the range of 6 mm to 18 mm.

[0117] The longitudinal and lateral extension dimensions of the baffle 122 may define an effective area of ​​the baffle 122. The "effective area" here refers to the area of ​​the portion of the baffle 122 that forms the second cavity together with the pinna (e.g., the area of ​​the hatched portion shown in FIG. 33). In some embodiments, the effective area of ​​the baffle 122 is 70 mm 2 ~1110mm 2 For example, the effective area of ​​the baffle 122 may be in the range of 84 mm 2 ~1060mm 2 For example, the effective area of ​​the baffle 122 may be in the range of 100 mm 2 ~900mm 2 may be in the range.

[0118] In some embodiments, the body 121 and the baffle 122 may be an integral structure, with the baffle 122 being the portion of the housing 120 that extends toward the user's ear canal and is placed adjacent to the face. In some embodiments, the body 121 and the baffle 122 may be separate structures that are assembled together. In some embodiments, the baffle 122 may be on a side of the body 121 (e.g., the side of the body 121 that faces the user's face).

[0119] In some embodiments, one of the two sound emission holes (e.g., the first sound emission hole 123) may be located on the side of the main body 121 facing the tragus, and the other sound emission hole (e.g., the second sound emission hole 124) may be located on the side where the baffle 122 is located, such that the first sound emission hole 123 is inside the second cavity and the second sound emission hole 124 is outside the second cavity.

[0120] FIG. 38 is a schematic diagram of an exemplary open-type earphone 100 according to some embodiments of the present disclosure. As shown in FIG. 38, the open-type earphone 100 includes an acoustic driver (not shown), a housing 120, and a suspension structure 130. The housing 120 includes a main body 121 and a baffle 122, where the main body 121 overlaps with the projection surface of the pinna, and the baffle 122 is located on the side of the main body 121 close to the ear canal and may overlap with the projection surface of the pinna. In some embodiments, the main body 121 may be partially located in the pinna (e.g., located in the upper pinna as shown in FIG. 38). In some embodiments, the main body 121 may be partially located in the lower pinna. In some embodiments, the main body 121 may be located to cover the tragus. In some embodiments, one of the two sound emission holes (e.g., the first sound emission hole 123) may be located on a side of the main body 121 that is close to the ear canal, and the other sound emission hole (e.g., the second sound emission hole 124) may be located on a side of the main body 121 that is away from the ear canal, such that the first sound emission hole 123 is inside the second cavity and the second sound emission hole 124 is outside the second cavity.

[0121] In some embodiments, when the body 121 is located in the auricle or overlaps with the auricle projection surface, in order to improve the listening volume of the open-type earphone 100, the effective area of ​​the baffle 122 is 15 mm 2 For example, the effective area of ​​the baffle 122 may be 20 mm 2 In some embodiments, when the main body 121 is located within the auricle or overlaps with the auricle projection, and when the main body 121 and the baffle 122 are arranged along the vertical direction (as shown in FIG. 38 ), the vertical extension dimension of the baffle 122 may be 0.8 cm or more. For example, the vertical extension dimension of the baffle 122 may be 1 cm or more.

[0122] 39 is a comparative diagram of frequency response curves of an example open-type earphone 100 with and without a baffle, according to some embodiments herein. As shown in FIG. 39, curve 381 is a curve of an earphone having a vertical extension dimension of 1 cm (or greater than 1 cm), or an effective area of ​​baffle 122 of 20 mm 2 The above shows the hearing frequency response curves of the open-type earphone 100 when the baffle 122 is installed, and curve 382 shows the hearing frequency response curve of the open-type earphone 100 when the baffle 122 is not installed. As can be seen from curves 381 and 382, ​​the hearing index of the open-type earphone 100 when the baffle 122 is installed can be improved by 5 dB or more compared to the hearing index when the baffle 122 is not installed.

[0123] FIG. 40 is a schematic diagram of an exemplary open-type earphone 100 according to some embodiments of the present disclosure. FIG. 41 is a cross-sectional view of the open-type earphone 100 shown in FIG. 40 along AA. FIG. 42 is a front view of an exemplary open-type earphone 100 according to some embodiments of the present disclosure when worn on a user's ear 101. FIG. 43 is a plan view of the open-type earphone 100 shown in FIG. 42 when worn on a user's ear 101. FIG. 44 is a bottom view of the open-type earphone 100 shown in FIG. 42 when worn on a user's ear 101. FIG. 45 is a plan view of an exemplary open-type earphone 100 according to other embodiments of the present disclosure. FIG. 46 is a bottom view of the open-type earphone 100 shown in FIG. 45. FIG. 47 is a plan view of an exemplary open-type earphone 100 according to further embodiments of the present disclosure. FIG. 48 is a bottom view of the open-type earphone 100 shown in FIG. 47.

[0124] As shown in Figs. 40 to 44, the open-type earphone 100 may include an acoustic driver 110, a housing 120, and a suspension structure 130. The housing 120 is an entire structure, and the suspension structure 130 has one end connected to the housing 120 and the other end extending along the auricle. One end of the housing 120 (e.g., the side away from the suspension structure 130) abuts against the user's auricle (e.g., abuts within the concha cavity 103, and as shown in Fig. 42, the housing 120 abuts against the edge 1031 of the concha cavity 103). The housing 120 defines a second cavity together with the auricle (e.g., the concha cavity 103). For example, as shown in Fig. 42, the surface of the housing 120 facing the auricle can define a second cavity together with the concha cavity. Also, for example, as shown in FIG. 45-FIG. 46 or FIG. 47-FIG. 48, the housing 120 may include a first bent portion 127 and a second bent portion 128. In some embodiments, the surfaces of the first bent portion 127 and the second bent portion 128 facing the auricle may define a second cavity together with the concha cavity. In some embodiments, the second bent portion 128 may define a second cavity together with the concha cavity. By providing the first bent portion 127, the open-type earphone 100 can better fit the shape of the ear during the wearing process and bypass the position of the front side of the helical crus or the tragus. At the same time, the installation of the first bent portion 127 allows the second bent portion 128 to abut more closely within the user's concha cavity, and the surface of the first bent portion 127 facing the auricle can form a more "complete" second cavity together with the concha cavity by abutting the end of the second bent portion 128 against the edge or inside of the user's concha cavity, and the volume of the formed second cavity is smaller (i.e., the second cavity has a smaller relative volume V / V0, which further improves the overall hearing index), and can better envelop the first sound emission hole and the ear canal opening. Furthermore, the installation of the first bent portion 127 allows the center of gravity of the entire housing 120 to be closer to the cut surface at the base of the ear, and the open-type earphone 100 becomes more stable when worn.In this case, the "ear base cut plane" refers to the plane where the ear base intersects with the user's head, and the "center of gravity of housing 120" refers to the overall center of gravity including all structures inside housing 120 (e.g., acoustic driver 110, core, battery, etc.) and the weight of housing 120 itself.

[0125] In some embodiments, the first bent portion 127 and the second bent portion 128 may be integrally molded to form the housing 120. In other embodiments, the first bent portion 127 and the second bent portion 128 may be integrally connected to form the housing 120 by a method such as insertion, locking, etc. In some embodiments, the included angle between the first bent portion 127 and the second bent portion 128 may be 90 degrees or more. The "included angle" here refers to the included angle between the two surfaces of the first bent portion 127 and the second bent portion 128 facing the auricle. For example, as shown in Figures 45 to 46, the included angle γ between the first bent portion 127 and the second bent portion 128 may be 90 degrees. For example, as shown in Figures 47 to 48, the included angle between the first bent portion 127 and the second bent portion 128 may be an obtuse angle. In addition, the included angle between the first bent portion 127 and the second bent portion 128 shown in Figs. 45 to 48 may be any angle that can form a second cavity together with the concha cavity, and is not limited here. The gap between the housing 120 and the ear canal opening 102 may be a leakage structure of the second cavity. By abutting the end of the housing 120 against the edge or inside of the user's concha cavity, the surface of the housing 120 facing the auricle can form a more "complete" second cavity together with the concha cavity, and the volume of the formed second cavity becomes smaller (i.e., the second cavity has a smaller relative volume V / V0, which further improves the hearing index overall), and can better enclose the first sound emission hole and the ear canal opening.

[0126] In some embodiments, in order to bring one end of the housing 120 (e.g., the side away from the hanging structure 130) into contact with the user's concha 103, the angle β between the surface 125 of the housing 120 facing the triangular fossa 104 and the tangent 126 of the connection between the hanging structure 130 and the housing 120 is in the range of 100° to 150°, as shown in Fig. 42. For example, the angle β between the surface 125 of the housing 120 facing the triangular fossa 104 and the tangent 126 of the connection between the hanging structure 130 and the housing 120 is in the range of 120° to 140°.

[0127] In some embodiments, when most users wear the open-type earphone 100, in order to allow the housing 120 to be inserted into the concha cavity and form a second cavity with high acoustic effect (e.g., the relative opening S / S0 of the second cavity is small), the distance between the upper surface of the housing 120 along the user's vertical axis (i.e., vertical direction) and the point of the suspension structure 130 that contacts the user's ear along the user's vertical axis may be in the range of 10 mm to 20 mm. As shown in FIG. 40, the distance between the upper surface of the housing 120 along the user's vertical axis and the point of the suspension structure 130 that contacts the user's ear along the user's vertical axis may be represented as LL. In some embodiments, the distance LL between the upper surface of the housing 120 along the user's vertical axis and the point of the suspension structure 130 that contacts the user's ear along the user's vertical axis may be in the range of 15 mm to 18 mm. In some embodiments, the length of the housing 120 along the long axis direction of the housing 120 on the surface away from the user's ear is within a range of 20 mm to 30 mm. As shown in FIG. 40, the length of the housing 120 along the long axis direction of the housing 120 on the surface away from the user's ear may be represented as a. In some embodiments, the length of the housing 120 along the short axis direction of the housing 120 on the surface away from the user's ear (which may also be called height) is within a range of 11 mm to 16 mm. As shown in FIG. 40, the length of the housing 120 along the short axis direction of the housing 120 on the surface away from the user's ear may be represented as h. In this specification, the "long axis direction" of the housing 120 is the direction in which the longest line segment connecting two points on the edge of the surface of the housing 120 exists on the surface facing the user's ear canal of the housing 120, and the "short axis direction" is the direction perpendicular to the long axis direction on the surface facing the user's ear canal of the housing 120 (shown in FIG. 51).

[0128] The first sound emission hole 123 and the second sound emission hole 124 of the open-type earphone 100 may be located inside and outside the second cavity, respectively, and the first sound emission hole 123 is disposed closer to the ear canal opening 102 than the second sound emission hole 124. As shown in Figs. 40 to 42, the sound emission hole located inside the second cavity (i.e., the first sound emission hole 123) may be located on the side of the housing 120 facing the ear canal. In some embodiments, according to Figs. 25A to 25B, the larger the volume of the cavity structure, the higher the hearing index in the low frequency band (for example, a frequency of 500 Hz or less). In order to improve the hearing index of the open-type earphone 100 at low frequencies, when the area of ​​the user's concha covered by the housing is constant, the larger the distance between the sound emission hole (i.e., the first sound emission hole 123) located inside the second cavity along the coronal axis direction of the human body and the wall surface of the concha (i.e., the height of the second cavity along the coronal axis direction of the human body), the larger the volume of the second cavity. In some embodiments, the distance between the sound emission hole (i.e., the first sound emission hole 123) located inside the second cavity and the wall surface of the concha along the coronal axis direction of the human body is within a range of 4 mm to 10 mm. In some embodiments, the greater the distance between the sound emission hole (i.e., the first sound emission hole 123) located inside the second cavity and the leaking structure (e.g., the gap formed by the upper and lower edges of the housing 120 and the auricle), the higher the acoustic effect, and at the same time, the sound emission hole located inside the second cavity is not too far from the ear canal, so that the minimum distance from the sound emission hole located inside the second cavity to the leaking structure (e.g., the upper edge or lower edge along the short axis direction of the housing) along the short axis direction of the housing may be in the range of 3 mm to 8 mm. For example, the minimum distance from the sound emission hole located inside the second cavity to the leaking structure (e.g., the upper edge or lower edge perpendicular to the short axis direction of the housing) along the short axis direction of the housing may be in the range of 4 mm to 6 mm. The minimum distance from the sound emission hole located inside the second cavity to the leaking structure is the minimum distance of the distance from the sound emission hole located inside the second cavity to the upper edge perpendicular to the short axis direction of the housing and the distance to the lower edge.

[0129] In some embodiments, the sound emission hole located outside the second cavity (i.e., the second sound emission hole 124) may be located on the side of the housing 120 away from the concha cavity. For example, as shown in FIG. 43, the sound emission hole located outside the second cavity (i.e., the second sound emission hole 124) may be located on the side of the housing 120 toward the triangular fossa. For example, as shown in FIG. 44, the sound emission hole located outside the second cavity (i.e., the second sound emission hole 124) may be located on the side of the housing 120 toward the earlobe. Furthermore, for example, the sound emission hole located outside the second cavity may include two or more sound emission holes, two of which are located on the side of the housing 120 toward the triangular fossa and the side of the housing 120 toward the earlobe, respectively.

[0130] In some embodiments, according to Figures 20A to 20D and their related descriptions, in order to improve the hearing index and make the hearing index at each frequency larger than that of a double-point (dipole) sound source that does not use a cavity structure, the relative distance L / d0 from the centroid of the opening of the cavity structure to the sound source located outside the cavity structure may be 1.78 or less. When a user wears the open-type earphone 100 shown in Figures 40 to 48, the relative distance L / d0 from the centroid of the opening of the cavity structure to the sound source located outside the cavity structure may be expressed as the ratio of the distance from the gap between the housing 120 and the ear canal opening 102 to the second sound emission hole 124 to the distance between the two sound emission holes. The "distance from the gap between the housing 120 and the ear canal opening 102 to the second sound emission hole 124" may be the distance between the center point (e.g., center point 4201 of the area 420 shown in FIG. 42) of the gap area (e.g., area 420 shown in FIG. 42) formed between the surface of the housing 120 facing the earlobe (e.g., earlobe 105 shown in FIG. 42) and the ear 101, and the second sound emission hole 124. In some embodiments, the ratio of the distance from the gap between the housing 120 and the ear canal opening 102 to the second sound emission hole 124 and the distance between the two sound emission holes may be less than 1.78. By way of example only, the ratio of the distance from the gap between the housing 120 and the ear canal opening 102 to the second sound emission hole 124 to the distance between the two sound emission holes may be less than 1.78, 1.68, 1.58, 1.48, 1.38, 1.28, 1.18 or 1.08, etc.

[0131] In some embodiments, according to FIG. 22 and its related description, in order to make the distance between the secondary sound source of the sound source located inside the cavity structure (i.e., the second cavity) and the sound source located outside the cavity structure (i.e., the second cavity) closer and improve the sound leakage reduction effect, the distance from the opening of the cavity structure to the external sound source may be smaller than the distance between the two sound sources. When a user wears the open-type earphone 100 shown in FIG. 40 to FIG. 48, the distance from the opening of the cavity structure (i.e., the second cavity) to the external sound source may be expressed as the distance from the gap between the housing 120 and the ear canal opening 102 to the second sound emission hole 124. In some embodiments, the distance from the gap between the housing 120 and the ear canal opening 102 to the second sound emission hole 124 may be smaller than the distance between the two sound emission holes (i.e., the first sound emission hole 123 and the second sound emission hole 124).

[0132] In some embodiments, according to Figs. 25A-25B and their related descriptions, in order to improve the overall hearing index, the relative volume V / V0 of the cavity structure (i.e., the second cavity) may be smaller than 1.75. The relative volume V / V0 of the cavity structure (i.e., the second cavity) may be expressed as a ratio between the volume of the second cavity and the reference volume. For example, the ratio between the volume of the second cavity and the reference volume may be smaller than 1.75. When a user wears the open-type earphone 100 shown in Figs. 40-44, the reference volume may be the cube of the distance from the gap between the housing 120 and the ear canal opening 102 to the sound emission hole (i.e., the second sound emission hole 124) located outside the second cavity. In some embodiments, the volume of the second cavity may be the volume of a sealed space surrounded by the concha cavity, the ear canal, the housing 120, the sound emission hole, and a curved surface surrounded by a gap that leaks sound. Thus, the volume of the second cavity can be measured with an ear gel injection mold. In some embodiments, the volume of the second cavity can be the product of the distance from the surface of the housing 120 facing the pinna / concha to the surface of the pinna / concha and the area enclosed by each contact point between the pinna and the housing 120. The distance from the surface of the housing 120 facing the pinna / concha to the surface of the pinna / concha can be the distance along the normal direction of the sound emission hole of the housing 120 to the surface of the pinna / concha. Each contact point between the pinna and the housing 120 can include contact points between the upper and lower edges of the housing 120 and the pinna, contact points between the ends of the housing 120 and the concha, end points of the housing 120 closest to the wall of the concha, etc., or any combination thereof.

[0133] In some embodiments, according to Figures 27A-27D, 28B-28E, and 29B-29E and their related descriptions, in a situation where the dual point sound source in which the cavity structure (i.e., the second cavity) is installed has a relative distance L / d0 from the centroid of the different openings to the external sound source and a relative area S / S0 of the different openings, in a frequency range audible by the human ear, the value of the sound pressure ratio Nsource of the two sound sources may be in the range of 0.2 to 2.0 to ensure that the dual point sound source in which the cavity structure is not installed has a larger hearing index than the dual point sound source structure in which the cavity structure is not installed. For example, the ratio between the volume (or sound pressure) of the sound derived from the sound output hole (e.g., the second sound output hole 124) located outside the second cavity and the volume (or sound pressure) of the sound derived from the sound output hole located inside the second cavity (e.g., the first sound output hole 123) is in the range of 0.2 to 2.0. As a mere example, the range of the ratio between the volume of the sound guided from the second sound output hole 124 and the volume of the sound guided from the first sound output hole 123 may be 0.6 to 1.4. Also, for example, the range of the ratio between the volume of the sound guided from the second sound output hole 124 and the volume of the sound guided from the first sound output hole 123 may be 0.7 to 1.3.

[0134] FIG. 49A is a schematic diagram of an exemplary open-type earphone according to some embodiments herein. FIG. 49B is a schematic diagram of an ear section according to some embodiments herein. FIG. 49C is a schematic diagram of an ear section according to some embodiments herein. FIG. 50A is a schematic diagram of an exemplary open-type earphone according to some embodiments herein. FIG. 50B is a schematic diagram of an exemplary open-type earphone according to some embodiments herein. FIG. 50C is a schematic diagram of an ear section according to some embodiments herein. In some embodiments, the ear canal of a user may be considered as a listening position, the ear canal faces the concha cavity, and the area of ​​the housing 120 covering the concha cavity of the user is 20 mm 2 or less, so that the second cavity defined by the housing 120 and the concha cavity encloses the listening position (i.e., the ear canal) as much as possible. 2 ~130mm 2In some embodiments, the area that the housing 120 covers of the user's concha may be measured by placing the open-type earphone 100 on a standard ear (e.g., a KB5000 / KB50001 anthropometric pinna manufactured by GRAS Sound&Vibration, Denmark, or any pinna conforming to the IEC 60318-7 standard). For example, when the housing 120 of the open-type earphone 100 does not abut the wall of the concha (as shown in FIG. 49A), the area that the housing 120 covers of the user's concha may be the area of ​​a triangular region formed by the two furthest contact points (contact points 491 and 492 shown in FIG. 49B) among the contact points between the housing 120 and the inner contour of the concha (the contour facing the person's face, the inner contour of the concha shown in FIG. 49C) and the furthest end point of the housing 120 away from the face (furthest end point 493 shown in FIG. 49B). Also, for example, when the housing 120 of the open-type earphone 100 abuts against the wall of the concha cavity (as shown in FIG. 50A) or the housing 120 of the open-type earphone 100 abuts against the pinna beyond the concha cavity (as shown in FIG. 50B), the area that the housing 120 covers of the user's concha cavity may be the area of ​​a triangular region formed by the two farthest contact points (contact points 501 and 502 shown in FIG. 50C) among the contact points between the housing 120 and the inner contour of the concha cavity (the contour toward the person's face) and the farthest end point (farthest end point 503 shown in FIG. 50C) of the housing 120 that contacts the wall of the concha cavity or the outer contour of the concha cavity (the contour away from the person's face, the outer contour shown in FIG. 49C). In addition, when a user is wearing the open-type earphone 100, the housing 120 may be suspended without touching the user, and therefore the contact point between the housing 120 and the inner or outer contour of the concha in this specification may be the intersection point between the projection of the housing 120 onto the contour of the user's concha and the inner or outer contour of the concha.

[0135] FIG. 51 is a schematic diagram of an exemplary open-type earphone according to some embodiments of the present disclosure. In some embodiments, the housing 120 may at least partially cover the user's ear canal as shown in FIG. 51 so that the second cavity envelops the listening position (i.e., the ear canal). In some embodiments, the ratio of the area of ​​the housing 120 covering the user's ear canal to the area of ​​the ear canal may be greater than 1 / 2. In some embodiments, the lower edge of the housing 120 along the short axis direction of the housing 120 may be lower than the center of the user's ear canal opening (e.g., closer to the user's earlobe). In some embodiments, the overlap distance h1 between the lower edge of the housing 120 and the user's ear canal along the short axis direction of the housing 120 may be in the range of 1 mm to 7.5 mm. 51, when the lower edge 511 of the housing 120 is parallel to the sagittal axis of the human body, the overlap distance h1 between the lower edge 511 of the housing 120 and the user's ear canal along the vertical axis direction of the human body (i.e., the short axis direction of the housing 120) may be within a range of 1 mm to 7.5 mm. Also, when the lower edge 511 of the housing 120 is not parallel to the sagittal axis of the human body, the overlap distance h1 between the lower edge 511 of the housing 120 and the user's ear canal along the short axis direction of the housing 120 may be within a range of 1 mm to 7.5 mm.

[0136] In some embodiments, the volume of the sound radiated from the first sound radiating hole 123 and the second sound radiating hole 124 may be adjusted and controlled by adjusting and controlling the sound output power of the acoustic driver 110. In some embodiments, acoustic structures may be installed in the first cavity corresponding to the first sound radiating hole 123 and the second sound radiating hole 124, respectively, and two sounds output by the acoustic driver 110 that are out of phase with each other are radiated through the first sound radiating hole 123 and the second sound radiating hole 124 by the acoustic structures, respectively, and the acoustic structures can adjust the ratio between the volume of the sound radiated from the sound radiating hole located outside the second cavity (i.e., the second sound radiating hole 124) and the volume of the sound radiated from the sound radiating hole located inside the second cavity (i.e., the first sound radiating hole 123). Exemplary acoustic structures may include slits, conduits, cavities, gauze, porous media, etc., or any combination thereof.

[0137] 31 to 44 are merely used for illustrative purposes and do not limit the present application. Those skilled in the art can make various changes and modifications based on the description of the present application. Although the achievable beneficial effects differ depending on the embodiment, in different embodiments, the achievable beneficial effects may be any one or a combination of any of the above, or any other achievable beneficial effects. For example, the housing 120 may have a circular structure and be entirely located in the concha cavity. Also, for example, the housing 120 may have an elliptical structure, one end of which abuts the concha cavity and the other end of which is located outside the auricle. Note that this specification describes an example in which there are two sound emission holes, but the number of sound emission holes is not limited, and there may be two or more sound emission holes, which guide the sound generated by the acoustic driver. This specification describes that the leakage structure includes only one opening, and the cavity structure (i.e., the second cavity) may include multiple openings.

[0138] Although the basic concept has been described above, it is clear to those skilled in the art that the detailed disclosure above is merely provided as an example and does not limit the present application. Although not explicitly described herein, those skilled in the art can make various changes, improvements and modifications to the present application. These changes, improvements and modifications are intended to be suggested by the present application and therefore still fall within the spirit and scope of the exemplary embodiments of the present application.

[0139] Also, certain terms are used herein to describe embodiments of the present application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the present application. Thus, it is emphasized and understood that references to "one embodiment" or "one embodiment" or "one alternative embodiment" more than once in various parts of this specification do not necessarily all refer to the same embodiment. Also, certain features, structures, or characteristics in one or more embodiments of the present application may be combined as appropriate.

[0140] Additionally, unless expressly stated in the claims, the order of enumeration of processing elements or sequences described herein, the use of alphanumeric characters, or the use of other designations, does not limit the order of procedures and methods of the present application. While the above disclosure describes through various examples what are presently believed to be various useful embodiments of the invention, it is to be understood that such details are merely illustrative and that the appended claims are not limited to only the disclosed embodiments, but on the contrary are intended to cover all modifications and equivalent combinations that are within the spirit and scope of the embodiments of the present application. For example, the system assembly described above may be implemented by a hardware device, but may also be implemented by a software-only solution, for example, by installing the described system on an existing server or mobile device.

[0141] Similarly, in the foregoing description of embodiments of the present application, various features may be grouped together in a single embodiment, figure, or description for the purpose of simplifying the description of the present disclosure and facilitating an understanding of one or more embodiments of the present invention. However, this method of disclosure should not be interpreted as reflecting an intention that the subject matter requires more features than are recited in each claim. In fact, an embodiment may include fewer than all features of a single embodiment disclosed above.

[0142] In some embodiments, numbers are used to describe components and attributes, and it is to be understood that the numbers described in such embodiments are modified in some instances by the modifiers "about," "approximately," or "substantially." Unless otherwise specified, "about," "approximately," or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, all numerical parameters used in the specification and claims are approximations that may vary depending on the characteristics required for a particular embodiment. In some embodiments, ordinary placekeeping techniques should be applied to the numerical parameters while taking into account the number of significant digits provided. In some embodiments, the numerical ranges and parameters for determining the ranges are approximations, however, in specific embodiments, such numerical values ​​are set as precisely as possible.

[0143] All patents, patent applications, published patent applications, and other materials, such as articles, books, specifications, publications, documents, etc., referenced in this application are incorporated herein by reference in their entirety, except for prosecution history documents that are inconsistent or inconsistent with the content of this application, and documents that may limit the broadest scope of the claims of this application (now or later related to this application). In addition, if a statement, definition, and / or use of a term in the accompanying documents of this application is inconsistent or inconsistent with the content set forth in this application, the statement, definition, and / or use of the term in this application shall control.

[0144] Finally, it should be understood that the embodiments herein are merely illustrative of the principles of the embodiments of the present application. Other variations may be within the scope of the present application. Thus, by way of example, and not of limitation, alternative configurations of the embodiments of the present application may be considered consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments expressly introduced and described herein. [Explanation of symbols]

[0145] 100 Open type earphones 101 Ear 102 External auditory canal ostium 103 Concha cavity 104 Triangular fossa 110 Acoustic Driver 120 Housing 121 Main unit 122 Baffle 123 First sound hole 124 Second sound hole 127 First bend 128 Second fold 130 Suspension structure

Claims

1. an acoustic driver that generates two sounds that are out of phase with each other; a housing that accommodates the acoustic driver and has two sound emission holes that output the two sounds that are in opposite phase to each other; a suspension structure for securing the housing near the user's ear in a position that does not block the user's ear canal; The housing includes a main body and a baffle, the main body defining a first cavity that accommodates the acoustic driver, the baffle connected to the main body and extending toward a user's ear canal and defining a second cavity together with the user's pinna, and the two sound emission holes are located inside and outside the second cavity, respectively.

2. 2. The open-type earphone according to claim 1, wherein the baffle is connected to a side of the main body away from a user's face and has a thickness smaller than a thickness of the main body.

3. 3. The open-type earphone according to claim 1, wherein a ratio of a distance from a boundary of the baffle close to a user's ear canal to a sound emission hole located outside the second cavity to a distance between the two sound emission holes is smaller than 1.

78.

4. The open-type earphone according to any one of claims 1 to 3, characterized in that a distance from a boundary of the baffle close to a user's ear canal to a sound emission hole located outside the second cavity is smaller than a distance between the two sound emission holes.

5. The open-type earphone according to any one of claims 1 to 4, characterized in that a ratio of the volume of the second cavity to a reference volume is smaller than 1.75, and the reference volume is the cube of a distance from a boundary of the baffle close to a user's ear canal to a sound emission hole located outside the second cavity.

6. The open-type earphone according to any one of claims 1 to 5, characterized in that a ratio between the volume of the sound guided from the sound output hole located outside the second cavity and the volume of the sound guided from the sound output hole located inside the second cavity is in a range of 0.2 to 2.

0.

7. 7. The open-type earphone according to claim 6, further comprising an acoustic structure, the acoustic structure adjusting a ratio between a volume of sound guided from a sound output hole located outside the second cavity and a volume of sound guided from a sound output hole located inside the second cavity, and comprising one of a slit, a conduit, a cavity, gauze, or a porous medium.

8. The open-type earphone according to any one of claims 1 to 7, characterized in that the sound emission hole located inside the second cavity is located between the user's ear canal and the sound emission hole located outside the second cavity.

9. The open-type earphone according to any one of claims 1 to 8, characterized in that, when the main body is located in front of the user's tragus, the baffle has a horizontal extension dimension in the range of 2 mm to 22 mm and a vertical extension dimension in the range of 2 mm to 10 mm.

10. The effective area of ​​the baffle is 84 mm ２ ~1060mm ２ 10. The open-type earphone according to claim 9, wherein the frequency of the open-type earphone is within a range of 0.1 to 1.0 Hz.

11. The open-type earphone according to claim 9 or 10, characterized in that one of the two sound emission holes is on a side of the main body facing the tragus, and the other sound emission hole is on a side where the baffle is located.

12. When the main body is located within the auricle or overlaps with the auricle projection surface, the longitudinal extension dimension of the baffle is 1 cm or more, or the effective area of ​​the baffle is 20 mm ２ The open-type earphone according to any one of claims 1 to 8, characterized in that:

13. The open-type earphone according to claim 12, characterized in that one of the two sound emission holes is located on a side of the main body facing the ear canal, and the other sound emission hole is located on a side of the main body away from the ear canal.

14. The open-type earphone according to any one of claims 1 to 13, characterized in that at least a part of an ear canal of a user is located inside the second cavity.

15. The open-type earphone according to any one of claims 1 to 14, characterized in that the housing at least partially covers the user's ear canal.

16. an acoustic driver that generates two sounds that are out of phase with each other; a housing that accommodates the acoustic driver and has two sound emission holes that output the two sounds that are in opposite phase to each other; a suspension structure, the suspension structure being configured to abut an end of the housing remote from the suspension structure against an auricle of a user; An open-type earphone, wherein the housing defines a first cavity that accommodates the acoustic driver and defines a second cavity together with the auricle, and the two sound emission holes are located inside and outside the second cavity, respectively.

17. 17. The open-type earphone according to claim 16, wherein one end of the housing remote from the suspension structure abuts against the concha cavity, and the housing defines the second cavity together with the concha cavity.

18. The open-type earphone according to claim 16 or 17, characterized in that the angle between the surface of the housing facing the triangular fossa and the tangent of the connection between the suspension structure and the housing is within the range of 100° to 150°.

19. The open-type earphone according to any one of claims 16 to 18, characterized in that the ratio of the distance from the gap between the housing and the ear canal opening to a sound emission hole located outside the second cavity to the distance between the two sound emission holes is smaller than 1.

78.

20. The open-type earphone according to any one of claims 16 to 19, characterized in that the distance from the gap between the housing and the ear canal opening to a sound emission hole located outside the second cavity is smaller than the distance between the two sound emission holes.

21. The open-type earphone according to any one of claims 16 to 20, characterized in that the ratio of the volume of the second cavity to the reference volume is smaller than 1.75, and the reference volume is the cube of the distance from the gap between the housing and the ear canal opening to a sound emission hole located outside the second cavity.

22. The open-type earphone according to any one of claims 16 to 21, characterized in that the ratio between the volume of the sound guided from the sound output hole located outside the second cavity and the volume of the sound guided from the sound output hole located inside the second cavity is in the range of 0.2 to 2.

0.

23. 23. The open-type earphone according to claim 22, further comprising an acoustic structure, the acoustic structure adjusting a ratio between a volume of sound guided from a sound output hole located outside the second cavity and a volume of sound guided from a sound output hole located inside the second cavity, and comprising one of a slit, a conduit, a cavity, gauze, or a porous medium.

24. The open-type earphone according to any one of claims 16 to 23, characterized in that the sound emission hole located inside the second cavity is located on the side of the housing facing the ear canal.

25. The open-type earphone according to claim 24, characterized in that the distance between the sound emission hole located inside the second cavity and the wall surface of the cavity of the concha is within a range of 4 mm to 10 mm along the coronal axis direction of the human body.

26. The open-type earphone according to claim 24 or 25, characterized in that the minimum distance along the short axis direction of the housing from a sound emission hole located inside the second cavity to an upper edge or a lower edge perpendicular to the short axis direction of the housing is within a range of 3 mm to 8 mm.

27. The open-type earphone according to any one of claims 24 to 26, characterized in that the sound emission hole located outside the second cavity is located on the side of the housing facing the triangular fossa or the side of the housing facing the earlobe.

28. The open-type earphone according to any one of claims 16 to 27, characterized in that the distance between an upper surface of the housing along the user's vertical axis direction and a point of the suspension structure that contacts the user's ear along the user's vertical axis direction is within a range of 10 mm to 20 mm.

29. The open-type earphone according to claim 28, characterized in that the length of the housing along the longitudinal direction of the housing on the surface away from the user's ear is within a range of 20 mm to 30 mm.

30. The open-type earphone according to claim 28 or 29, characterized in that the length of the housing along the minor axis direction of the housing on the surface away from the user's ear is within a range of 11 mm to 16 mm.

31. The area of ​​the housing covering the user's concha is 20 mm ２ ~130mm ２ The open-type earphone according to any one of claims 16 to 30, characterized in that the range of

32. The open-type earphone according to any one of claims 16 to 31, characterized in that the housing at least partially covers the user's ear canal.

33. 33. The open-type earphone according to claim 32, wherein the ratio of the area of ​​the housing covering the cavity of the user's concha to the area of ​​the ear canal is greater than 1 / 2.

34. The open-type earphone according to claim 32 or 33, characterized in that an overlap distance between a lower edge of the housing and a user's ear canal along a short axis direction of the housing is within a range of 1 mm to 7.5 mm.

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