Open-type earphones

Abstract

This invention provides open-type earphones that improve the volume of near-field audio signals while simultaneously reducing the volume of far-field sound leakage. [Solution] An open-type earphone 100 according to an embodiment of this specification includes an acoustic driver 110 that generates two sounds with opposite phases, a housing 120 that houses the acoustic driver 110 and is provided with two sound outlets 123 and 124 that each emit two sounds with opposite phases, and a suspension structure 130 that fixes the housing 120 near the user's ear 101 in a position that does not obstruct the user's ear canal, wherein the housing 120 includes a main body 121 and a baffle 122, the main body 121 defining a first cavity that houses the acoustic driver 110, the baffle 122 is connected to the main body and extends toward the user's ear canal, defining a second cavity together with the user's auricle, and the two sound outlets are located inside and outside the second cavity, respectively.

Description

[Technical Field]

[0001] This specification relates to the field of acoustics, and more particularly to open-type earphones.

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

[0003] Earphones are portable audio output devices capable of transmitting sound. To solve the problem of sound leakage from earphones, two or more sound sources are typically 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 between two sound sources with opposite phases is essentially negligible, so the two acoustic signals cancel each other out, reducing far-field sound leakage. While this method can achieve a certain degree of sound leakage reduction, it still has certain limitations. For example, suppressing the far-field acoustic signal also reduces the volume of the near-field audio signal, and the phase difference increases as the signal frequency increases, so this method is less effective at suppressing high-frequency far-field signals.

[0004] Therefore, it is desirable to provide earphones that can improve the volume of near-field audio signals while simultaneously reducing the volume of far-field sound leakage, thereby more effectively reducing sound leakage. [Overview of the project] [Means for solving the problem]

[0005] An open-type earphone according to one embodiment of this specification includes an acoustic driver that generates two sounds with opposite phases, a housing that houses the acoustic driver and is provided with two sound outlets that each emit the two sounds with opposite phases, and a suspension structure that fixes the housing near the user's ear in a position that does not obstruct the user's ear canal, wherein the housing includes a main body and a baffle, the main body defining a first cavity for housing the acoustic driver, the baffle being connected to the main body and extending toward the user's ear canal, defining a second cavity together with the user's auricle, and the two sound outlets being located inside and outside the second cavity, respectively.

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

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

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

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

[0010] In some embodiments, the ratio of the volume of sound emitted from a sound vent located outside the second cavity to the volume of sound emitted from a sound vent 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 which adjusts the ratio between the volume of sound emitted from a sound outlet located outside the second cavity and the volume of sound emitted from a sound outlet located inside the second cavity, and includes one of a slit, conduit, cavity, gauze, or porous medium.

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

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

[0014] In some embodiments, the effective area of ​​the baffle is 84 mm². 2 ~1060mm 2 It is within the range.

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

[0016] In some embodiments, when the main body is located inside the auricle or overlaps with the auricle projection surface, the vertical extension dimension of the baffle is 1 cm or more, or the effective area of ​​the baffle is 20 mm². 2 That's all.

[0017] In some embodiments, one of the two sound vents is located on the side of the main body facing the ear canal, and the other sound vent is located on the side of the main body away from the ear canal.

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

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

[0020] Another open 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 is provided with two sound output holes respectively leading out the two sounds with opposite phases; and a suspension structure, one end of the housing abutting against the user's concha cavity through the suspension structure, wherein the housing defines a first cavity for accommodating the acoustic driver, and defines a second cavity together with the concha cavity, and the two sound output holes are respectively located inside and outside the second cavity.

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

[0022] In some embodiments, a ratio of a distance from a gap between the housing and the external auditory meatus to the sound output hole located outside the second cavity to a distance between the two sound output holes is less than 1.78.

[0023] In some embodiments, the distance from the gap between the housing and the external auditory meatus to the sound output hole located outside the second cavity is smaller than the distance between the two sound output holes.

[0024] In some embodiments, a 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 external auditory meatus to the sound output hole located outside the second cavity.

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

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

[0027] In some embodiments, the sound vent located inside the second cavity is positioned on the side of the housing facing the ear canal.

[0028] In some embodiments, the sound vent located outside the second cavity is positioned either toward the triangular fossa of the housing or toward the earlobe of the housing.

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

[0030] In some embodiments, the housing has a length along its long axis at a surface away from the user's ears that is in the range of 20 mm to 30 mm.

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

[0032] This specification will be further described by exemplary embodiments, which will be described in detail with reference to the drawings. These embodiments are not limiting, and in these embodiments the same numbers indicate the same structure. [Brief explanation of the drawing]

[0033] [Figure 1] This is an illustrative diagram of an open-type earphone configuration according to some embodiments of this specification. [Figure 2] This is a schematic diagram of two point sound sources relating to some embodiments of this specification. [Figure 3] This is a schematic diagram illustrating the measurement of sound leakage according to some embodiments of this specification. [Figure 4] This is a comparative diagram of the sound leakage index at different frequencies for single-point and dual-point sound sources according to some embodiments of this specification. [Figure 5] These are frequency response characteristic curves at near-field listening positions for dipole sound sources with different spacings, according to some embodiments of this specification. [Figure 6] This is a schematic diagram of two point sources and listening positions according to some embodiments of this specification. [Figure 7] This figure shows the sound leakage index in the far field for dipole sound sources with different spacings, according to some embodiments of this specification. [Figure 8] This is a schematic diagram illustrating an exemplary distribution in which a baffle is installed around one of the dipole sound sources according to some embodiments of this specification. [Figure 9] This figure shows the sound leakage index in some embodiments of this specification, with and without a baffle installed around one of the dipole sound sources. [Figure 10] This is a schematic diagram illustrating some embodiments of this specification in which a dipole sound source with a baffle is located at different listening positions in the near field. [Figure 11] These are frequency response curve diagrams for a dipole sound source with a baffle, according to some embodiments of this specification, when it is located at different listening positions in the near field. [Figure 12] This is a schematic diagram illustrating an exemplary distribution when a cavity structure is installed around one of the dipole sound sources according to some embodiments of this specification. [Figure 13] This is a schematic diagram illustrating the principle of a dipole sound source structure and a case in which a cavity structure is installed around one of the dipole sound sources, according to some embodiments of this specification. [Figure 14A]This is a schematic diagram of a monopole sound source according to some embodiments of this specification. [Figure 14B] This is a schematic diagram of a dipole sound source according to some embodiments of this specification. [Figure 14C] This is a schematic diagram showing a case in which a baffle structure is installed around one of the dipole sound sources according to some embodiments of this specification. [Figure 14D] This is a schematic diagram showing a case where a cavity structure is installed around one of the dipole sound sources according to some embodiments of this specification. [Figure 15A] This diagram shows the frequency response characteristic curves of the sound being heard and the sound leakage at the listening position of a monopole sound source according to some embodiments of this specification. [Figure 15B] This diagram shows the frequency response characteristic curves of the sound being heard and the sound leakage at the listening position of a dipole sound source according to some embodiments of this specification. [Figure 15C] This diagram shows the frequency response characteristics curves of sound perception and sound leakage at the listening position when a baffle structure is installed around one of the dipole sound sources according to some embodiments of this specification. [Figure 15D] This diagram shows the frequency response characteristics of sound perception and sound leakage at the listening position when a cavity structure is installed around one of the dipole sound sources according to some embodiments of this specification. [Figure 16] This is a schematic diagram of the auditory index for some embodiments of this specification, including a monopole sound source, a dipole sound source, a case where a baffle structure is installed around one of the dipole sound sources, and a case where a cavity structure is installed around one of the dipole sound sources. [Figure 17] This is a schematic diagram of a cavity structure according to some embodiments of this specification. [Figure 18] These are auditory index curves of cavity structures having leak structures of different sizes, according to some embodiments of this specification. [Figure 19] This is a sonic index curve diagram of a cavity structure having leak structures at different locations, according to some embodiments of this specification. [Figure 20A]This is a diagram of auditory index curves at a frequency of 500 Hz for cavity structures having leak structures of different positions and sizes according to some embodiments of this specification. [Figure 20B] This is a diagram of auditory index curves at a frequency of 1000 Hz for cavity structures having leak structures of different positions and sizes according to some embodiments of this specification. [Figure 20C] This is a diagram of auditory index curves at a frequency of 2000 Hz for cavity structures having leak structures of different positions and sizes according to some embodiments of this specification. [Figure 20D] This is a diagram of auditory index curves at a frequency of 5000 Hz for cavity structures having leak structures of different positions and sizes according to some embodiments of this specification. [Figure 21A] This is a schematic diagram of a cavity structure having two horizontal openings according to some embodiments of this specification. [Figure 21B] This is a schematic diagram of a cavity structure having two vertical openings according to some embodiments of this specification. [Figure 22] This is a comparative diagram of the auditory index curves of a cavity structure having two openings and a cavity structure having one opening, according to some embodiments of this specification. [Figure 23A] This is a schematic diagram of a cavity structure having one opening, according to some embodiments of this specification. [Figure 23B] This is a schematic diagram of a cavity structure having two openings according to some embodiments of this specification. [Figure 23C] This is a schematic diagram of a cavity structure having three openings according to some embodiments of this specification. [Figure 23D] This is a schematic diagram of a cavity structure having four openings according to some embodiments of this specification. [Figure 24] This is a comparative diagram of auditory index curves for cavity structures with different numbers of openings, according to some embodiments of this specification. [Figure 25A] This is a schematic diagram of a cavity structure having one opening, according to some embodiments of this specification. [Figure 25B] This is a comparative diagram of auditory index curves for different relative volumes of cavity structures having one opening, according to some embodiments of this specification. [Figure 26A] This is a schematic diagram of a cavity structure having one opening, according to some embodiments of this specification. [Figure 26B] This is a comparative diagram of auditory indices for cavity structures having different sound pressure ratio (Nsource) values, according to some embodiments of this specification. [Figure 27A] Figure 26A shows auditory index curves at a frequency of 20 Hz for several embodiments of this specification, where the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). [Figure 27B] Figure 26A shows auditory index curves at a frequency of 100 Hz for cavity structures of different sizes and different sound pressure ratios (Nsource) according to some embodiments of this specification. [Figure 27C] Figure 26A shows auditory index curves at a frequency of 1000 Hz for cavity structures of different sizes and different sound pressure ratios (Nsource) according to some embodiments of this specification. [Figure 27D] Figure 26A shows auditory index curves at a frequency of 10,000 Hz for cavity structures of different sizes and different sound pressure ratios (Nsource) according to some embodiments of this specification. [Figure 28A] This is a schematic diagram of a cavity structure having one opening, according to some embodiments of this specification. [Figure 28B] Figure 28A shows auditory index curves at a frequency of 20 Hz for several embodiments of this specification, where the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). [Figure 28C] Figure 28A shows auditory index curves at a frequency of 100 Hz for several embodiments of this specification, where the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). [Figure 28D]Figure 28A shows auditory index curves at a frequency of 1000 Hz for several embodiments of this specification, where the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). [Figure 28E] Figure 28A shows auditory index curves at a frequency of 10,000 Hz for cavity structures of different sizes and different sound pressure ratios (Nsource) according to some embodiments of this specification. [Figure 29A] This is a schematic diagram of a cavity structure having one opening, according to some embodiments of this specification. [Figure 29B] Figure 29A shows auditory index curves at a frequency of 20 Hz for several embodiments of this specification, where the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). [Figure 29C] Figure 29A shows auditory index curves at a frequency of 100 Hz for cavity structures of different sizes and different sound pressure ratios (Nsource) according to some embodiments of this specification. [Figure 29D] Figure 29A shows auditory index curves at a frequency of 1000 Hz for cavity structures of different sizes and different sound pressure ratios (Nsource) according to some embodiments of this specification. [Figure 29E] Figure 29A shows auditory index curves at a frequency of 10,000 Hz for several embodiments of this specification, where the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). [Figure 30] This is a block diagram of an exemplary open-type earphone according to some embodiments of this specification. [Figure 31] This is a schematic diagram of an exemplary open-type earphone according to some embodiments of this specification. [Figure 32] This is a schematic diagram of an exemplary housing configuration according to some embodiments of this specification. [Figure 33] This is a schematic diagram of an exemplary housing configuration according to some embodiments of this specification. [Figure 34A]This diagram shows the sound field of open-type earphones without baffles. [Figure 34B] Figure 33 shows the sound field of an open-type earphone with a baffle. [Figure 35] This is a comparison chart of the frequency response curves of open-type earphones without a baffle and open-type earphones with a baffle. [Figure 36] This is a curve diagram showing the difference between the listening volume and the sound leakage volume for open-type earphones without a baffle and open-type earphones with a baffle. [Figure 37A] Figure 33 shows the change in auditory volume for different baffle lengths in the lateral and vertical directions when the frequency is 500 Hz. [Figure 37B] Figure 33 shows the change in auditory volume for different baffle lengths in the lateral and vertical directions when the frequency is 1000 Hz. [Figure 37C] Figure 33 shows the change in sound leakage volume for different baffle lengths in the lateral and vertical directions when the frequency is 500 Hz. [Figure 37D] Figure 33 shows the change in sound leakage volume for different baffle lengths in the lateral and vertical extension dimensions when the frequency is 1000 Hz. [Figure 38] This is a schematic diagram of an exemplary open-type earphone according to some embodiments of this specification. [Figure 39] This is a comparison diagram of the frequency response curves of an exemplary open-type earphone according to some embodiments of this specification, showing the case with a baffle and the case without a baffle. [Figure 40] This is a schematic diagram of an exemplary open-type earphone according to some embodiments of this specification. [Figure 41] Figure 40 is a cross-sectional view of an open-type earphone along AA. [Figure 42] This is a front view of an exemplary open-type earphone, according to some embodiments of this specification, when worn in the user's ear. [Figure 43] Figure 42 is a plan view of the open-type earphones when they are worn in the user's ears. [Figure 44] Figure 42 is a bottom view of the open-type earphone when it is worn in the user's ear. [Figure 45] This is a plan view of an exemplary open-type earphone relating to some other embodiments of this specification. [Figure 46] Figure 45 is a bottom view of the open-type earphone shown. [Figure 47] This is a plan view of an exemplary open-type earphone relating to some further embodiments of this specification. [Figure 48] Figure 47 is a bottom view of the open-type earphone shown. [Figure 49A] This is a schematic diagram illustrating the fitting of an exemplary open-type earphone according to some embodiments of this specification. [Figure 49B] This is a schematic diagram of the ear portion according to some embodiments of this specification. [Figure 49C] This is a schematic diagram of the ear portion according to some embodiments of this specification. [Figure 50A] This is a schematic diagram illustrating the fitting of an exemplary open-type earphone according to some embodiments of this specification. [Figure 50B] This is a schematic diagram illustrating the fitting of an exemplary open-type earphone according to some embodiments of this specification. [Figure 50C] This is a schematic diagram of the ear portion according to some embodiments of this specification. [Figure 51] This is a schematic diagram illustrating the fitting of an exemplary open-type earphone according to some embodiments of this specification. [Modes for carrying out the invention]

[0034] To more clearly illustrate the technical means of the embodiments of this application, the drawings necessary for describing the embodiments are briefly described below. Clearly, the drawings described below are only a few examples or embodiments of this application, and those skilled in the art can apply this application to other similar scenarios based on these drawings without requiring any creative effort. Unless otherwise evident from the context or explicitly stated, the same reference numerals in the drawings represent the same structure or operation.

[0035] It should be understood that the terms “system,” “apparatus,” “unit,” and / or “module” as used herein are ways of distinguishing various assemblies, parts, components, sections, or assemblies of different levels. However, other terms may be used in place of the above terms if they can achieve the same purpose.

[0036] As shown in the present application and claims, unless the context explicitly indicates otherwise, terms such as “one,” “one,” “one kind,” and / or “the” do not specifically mean singular and may include plural forms. Generally, the terms “includes” and “contains” merely indicate the inclusion of clearly identified steps and elements, which are not an exclusive list, and the method or apparatus may also include other steps or elements.

[0037] In the embodiments described herein, open-type earphones are described. When a user wears an open-type earphone, the housing can be fixed via a suspension structure in a position near the user's ear, without obstructing the user's ear canal. The open-type earphone may be worn on the user's head (e.g., open-type earphones worn with glasses or in other structural ways), on other parts of the user's body (e.g., the user's neck / shoulder area), or positioned near the user's ear in other ways (e.g., handheld). 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 houses the acoustic driver and is provided with two sound outlets, each for emitting the two sounds with opposite phases.

[0038] In some embodiments, the suspension structure secures the housing near the user's ear, in a position that does not obstruct the user's ear canal. In some embodiments, the housing may include a body and a baffle. The body defines a first cavity for housing the acoustic driver. The baffle is connected to the body and extends toward the user's ear canal, defining a second cavity together with the user's auricle. Two sound vents are located inside and outside the second cavity, respectively.

[0039] In some other embodiments, the suspension structure abuts one end of the housing (for example, the end away from the suspension structure) against the user's concha. The housing defines a first cavity for housing the acoustic driver and, together with the concha, defines a second cavity. Two sound vents are located inside and outside the second cavity, respectively.

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

[0041] Figure 1 is a diagram illustrating the configuration of an exemplary open-type earphone 100 according to some embodiments of this specification. As shown in Figure 1, the open-type earphone 100 may include an acoustic driver 110, a housing 120, and a suspension structure 130. In some embodiments, the housing 120 of the open-type earphone 100 may be attached to the user's body (e.g., the head, neck, or upper torso) via the suspension structure 130, and at the same time, the housing 120 and acoustic driver 110 may be close to the ear canal but not block it, thereby keeping the user's ear 101 open and allowing the user to hear not only the sound output from the open-type earphone 100 but also sounds from the external environment. For example, the open-type earphone 100 may be mounted 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 attached to the user's body and house the acoustic driver 110. In some embodiments, the housing 120 may be a hollow, sealed housing structure, and the acoustic driver 110 may be located inside the housing 120. In some embodiments, the open-type earphone 100 may be combined with products such as glasses, headphones, head-mounted displays, or AR / VR helmets, in which case the housing 120 may be fixed near the user's ear 101 by suspension or clamping. In some alternative embodiments, a suspension structure (e.g., a hook) may be installed on the housing 120. For example, the shape of the hook may conform to the shape of the auricle, and the open-type earphone 100 may be attached independently to the user's ear 101 via the hook.

[0043] In some embodiments, the housing 120 may have a housing structure that conforms to the shape of the human ear 101, such as an annular, elliptical, (regular or irregular) polygonal, U-shaped, V-shaped, or semicircular shape, so that it can be directly placed on the user's ear 101. In some embodiments, the housing 120 may further include a fixing structure. The fixing structure may include ear hooks, elastic bands, etc., to better secure the open-type earphone 100 to the user and prevent it from falling out during use.

[0044] In some embodiments, when a user is wearing an open-type earphone 100, the housing 120 may be positioned above, below, in front of (e.g., in front of the tragus) or inside the auricle (e.g., inside the concha). The housing 120 may further have two or more sound vents for transmitting sound. In some embodiments, the acoustic driver 110 may output sound having a phase difference (e.g., inverse phase) through the two sound vents.

[0045] The acoustic driver 110 is a component that receives an electrical signal, converts it into an audio signal, and outputs it. In some embodiments, distinguished by frequency, the type of 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, low frequency, high frequency, etc., only represent approximate frequency ranges, and different application scenes may have different division methods. For example, a crossover frequency may be determined, with low frequencies representing the frequency range below the crossover frequency, and high frequencies representing frequencies above the crossover frequency. The crossover frequency may be any value within the range of human hearing, 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 an acoustic driver 110, which is capable of generating sound by the core, and the sound is transmitted along the corresponding acoustic path to the corresponding sound vents and output from the sound vents. The motherboard may be electrically connected to the core to control the core's sound generation. In some embodiments, the motherboard may be positioned close to the core in the housing 120 to reduce the wiring distance between the core and other components (e.g., function buttons).

[0047] In some embodiments, the acoustic driver 110 may include a diaphragm. When the diaphragm vibrates, sound is emitted from the front and rear sides of the diaphragm, respectively. In some embodiments, a sound-transmitting front cavity (not shown) is provided at the front of the diaphragm within the housing 120. The front cavity is acoustically coupled to one of its sound outlets (e.g., a first sound outlet), so that sound from the front of the diaphragm can be emitted from the first sound outlet via the front cavity. A sound-transmitting rear cavity (not shown) is provided at the rear of the diaphragm within the housing 120. The rear cavity is acoustically coupled to another sound outlet (e.g., a second sound outlet), so that sound from the rear of the diaphragm can be emitted from the second sound outlet 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 the front and rear cavities of the acoustic driver 110. In some embodiments, the open-type earphone 100 may further include a power supply (not shown). The power supply may be installed at any location on the open-type earphone 100, for example, at a location on the housing 120 away from the acoustic driver 110 or at a location close to the acoustic driver 110. In some embodiments, the location of the power supply may be rationally set depending on the weight distribution of the open-type earphone 100, thereby equalizing the weight distribution of the open-type earphone 100 and improving the comfort and stability of the open-type earphone 100 when worn by the user. In some embodiments, the power supply may supply power to individual components of the open-type earphone 100 (e.g., the acoustic driver 110, the core, etc.). The power supply can be electrically connected to the acoustic driver 110 and / or the core and supply power to them. Furthermore, when the diaphragm is vibrating, a pair of sound signals with a phase difference (for example, opposite phases) can be generated simultaneously on the front and rear sides of the diaphragm. After the sound signals pass through the front cavity and rear cavity, respectively, they propagate outward from the positions of the first and second sound outlets.In some embodiments, the structure of the front cavity and rear cavity may be configured such that the sound output from the first and second sound outlets of the acoustic driver 110 satisfies certain conditions. For example, by designing the lengths of the front cavity and rear cavity, a set of sounds with a specific phase relationship (e.g., opposite phase) can be output from the first and second sound outlets, thereby reducing the near-field listening volume of the open-type earphone 100 and effectively improving the far-field sound leakage problem.

[0048] To further explain the effect of sound vents distributed on both sides of the auricle on the sound output effect of open-type earphones, this specification equates the open-type earphone and the auricle with a dual-point source-baffle model.

[0049] For the sake of explanation, if the dimensions of the sound vents of open-type earphones are small, each sound vent can be considered approximately as a single point source. The sound field sound pressure p generated by a single point source satisfies equation (1).

[0050]

number

[0051] In the equation, 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, k is the wavenumber, and the magnitude of the sound field sound pressure of a point source is inversely proportional to the distance to the point source.

[0052] As described above, by configuring a dipole sound source by installing two sound vents (for example, a first sound vent and a second sound vent) in the open-type earphone 100, the sound radiated 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 vents, i.e., the dipole sound source, has a certain phase difference. When certain conditions are met, such as the position and phase difference between the dipole sound sources, the open-type earphone can achieve different sound effects in the near field and the far field. For example, if the phases of the point sound sources corresponding to the two sound vents are opposite, that is, if the absolute value of the phase difference between the two point sound sources is 180°, then, according to the principle that sound waves with opposite phases cancel each other out, a reduction in sound leakage in the far field can be achieved. Also, for example, if the phases of the point sound sources corresponding to the two sound vents are approximately opposite, a reduction in sound leakage in the far field can also be achieved. As a simple example, the absolute value of the phase difference between two point sources used to reduce sound leakage in the distant field may be within the range of 120° to 240°.

[0053] Figure 2 is a schematic diagram of two point sound sources according to some embodiments of this specification.

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

[0055]

number

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

[0057]

number

[0058] In the formula, r is the distance between any target point in space and the center of the dipole sound source, and θ represents the angle between the line connecting the target point and the center of the dipole sound source and the 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 the target point in the 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 sufficiently large to satisfy the listening needs, while simultaneously ensuring that the sound pressure radiated into the distant field is sufficiently small to reduce sound leakage. Therefore, the sound leakage index α can be used as an indicator to evaluate the ability to reduce sound leakage.

[0061]

number

[0062] In the formula, P far This represents the sound pressure at a distance for open-type earphones (i.e., the sound leakage pressure at a distance), and P ear This represents the sound pressure around the user's ear (i.e., near-field auditory sound pressure). As can be seen from equation (4), the smaller the sound leakage index, the better the sound leakage reduction ability of open-type earphones, and if the near-field auditory volume at the listening position is the same, the far-field sound leakage will be smaller.

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

[0064] Figure 4 is a comparative diagram of the sound leakage index at different frequencies for single-point and dual-point sound sources according to some embodiments of this specification. The dual-point sound source (also called a dipole sound source) in Figure 4 may be a typical dual-point sound source, that is, the spacing is constant, the amplitudes of the two point sound sources are the same, and the phases of the two point sound sources are opposite. Note that a typical dual-point sound source is selected to explain only the principle and effect, and the parameters of each point sound source can be adjusted according to actual needs to create a certain difference from a typical dual-point sound source. As shown in Figure 4, when the spacing is constant, the sound leakage generated by the dual-point sound source increases with increasing frequency, and the sound leakage reduction ability weakens with increasing frequency. When the frequency is greater than a certain frequency value (for example, around 8000 Hz as shown in Figure 4), the generated sound leakage is greater than that of a single-point sound source, and this frequency (for example, 8000 Hz) is the upper frequency limit at which the dual-point sound source can reduce sound leakage.

[0065] To adjust the output effect of a dipole source (e.g., reducing the sound leakage index), the interval d between the dipole sources can be adjusted. Figure 5 shows the frequency response characteristic curves at a near-field listening position for dipole sources with different intervals according to some embodiments of this specification. As shown in Figure 5, as the interval between point source A1 and point source A2 gradually increases (e.g., from d to 10d), the volume at the listening position gradually increases. This is because, as the interval between point source A1 and point source A2 increases, the sound from the two paths reaching the listening position has a larger amplitude difference (i.e., a larger sound pressure difference) and a larger acoustic distance difference, thus reducing the sound cancellation effect and further increasing the volume at the listening position. However, because sound cancellation still exists, the volume at the listening position is still lower than the volume produced by a single point source of the same intensity at the same position in the mid-to-low frequency band (e.g., sound with a frequency lower than 1000 Hz). In the high-frequency range (for example, speech with frequencies close to 10,000 Hz), the wavelength of the speech becomes smaller, so the conditions for synergistic sound generation appear, and as a result, the speech generated by a dipole source is louder than the speech generated by a single-point source. In the embodiments of this specification, the sound pressure amplitude, i.e., the sound pressure, may be the pressure of the speech due to air vibrations.

[0066] In some embodiments, increasing the spacing between dipole sound sources can increase the volume at the listening position. However, as the spacing increases, the cancellation ability of the dipole sound sources weakens, further increasing far-field sound leakage. For illustrative purposes only, Figure 6 is a schematic diagram of two point sources and a listening position according to some embodiments of this specification. Figure 7 is a diagram showing the far-field sound leakage index of dipole sound sources with different spacings according to some embodiments of this specification. Based on the listening position shown in Figure 6, point sources A1 and A2 are located on the same side of the listening position, with point source A1 being closer to the listening position, and point sources A1 and A2 each output sound with the same amplitude but opposite phase. The method for measuring sound leakage involves selecting the average value of the sound pressure amplitude at each point on a sphere with a radius of 50 cm, with the center of the dual point source as the center, and calculating the far-field sound leakage index for a single point source and dipole sound sources with different spacings. As shown in Figure 7, using the far-field sound leakage index of a single-point source as a reference, the far-field sound leakage index gradually increases as the distance between dipole sources increases from d to 10d, indicating a gradual increase in sound leakage. Simultaneously, the frequency band in which sound leakage can be reduced compared to a single-point source gradually narrows. Note that the selection of the method for measuring sound leakage described above is merely for the purpose of explaining the principle and effect.

[0067] In some embodiments, a baffle may be placed around one of the dual point sources to improve the output effect of open-type earphones, that is, 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 of a case in which a baffle is placed around one of the dipole sources according to some embodiments of this specification. As shown in Figure 8, when a baffle is placed between point source A1 and point source A2, in the near field, the sound field of point source A2 can interfere with the sound waves of point source A1 at the listening position only by bypassing the baffle, which corresponds to an increase in the acoustic distance from point source A2 to the listening position. Therefore, assuming that point source A1 and point source A2 have the same amplitude, the amplitude difference of the sound waves of point source A1 and point source A2 at the listening position increases compared to when no baffle is placed, which reduces the degree to which the sounds from the two paths cancel each other out at the listening position, and increases the volume at the listening position. In the far field, sound waves generated by point sources A1 and A2 can interfere with each other within a wide spatial range without bypassing the baffle (similar to the case without a baffle), so the sound leakage in the far field does not increase significantly compared to the case without a baffle. Therefore, by installing a baffle structure around one of the point sources A1 and A2, if the sound leakage volume in the far field does not increase significantly, the volume at the near-field listening position can be significantly increased.

[0068] Figure 9 shows the sound leakage index for several embodiments of this specification, with and without a baffle installed around one of the dipole sound sources. After adding a baffle to the dual-point sound source, in the near field, it is equivalent to increasing the distance between the two point sound sources, and the volume at the near-field listening position is equivalent to that generated by a dual-point sound source at a greater distance, so the listening volume in the near field is clearly increased compared to the case without a baffle. In the far field, the sound field of the two point sound sources is less affected by the baffle, and the resulting sound leakage is equivalent to that generated by a dual-point sound source at a smaller distance. Therefore, as shown in Figure 9, after adding a baffle, the sound leakage index is significantly lower than in the case without a baffle, that is, at the same listening volume, the sound leakage in the far field is smaller than in the case without a baffle, and the sound leakage reduction capability is clearly stronger.

[0069] In some embodiments, on the premise that the spacing between dipole sound sources is kept constant, the listening position has a certain influence on the near-field listening volume and the far-field sound leakage reduction with respect to the positions of the dipole sound sources. In order to improve the output effect of open earphones, in some embodiments, two sound output holes may be provided in the open earphone. When a user wears the earphone, the two sound output holes are respectively located on the front and rear sides of the baffle. In some embodiments, considering that the sound emitted from the sound output hole located on the rear side of the baffle needs to bypass the baffle to reach the user's external auditory canal, the acoustic path from the sound output hole located on the front side of the baffle to the user's external auditory canal (that is, the acoustic distance from the sound output hole to the opening of the user's external auditory canal) is shorter than the acoustic path from the sound output 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, as an illustrative description, in the embodiments of the present specification, Figure 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 the present specification. As shown in Figure 10, four representative listening positions (Listening Position 1, Listening Position 2, Listening Position 3, and Listening Position 4) are selected to explain the effect and principle of the selection of the listening position. Listening Position 1, Listening Position 2, and Listening Position 3 are equally spaced from the point sound source A1, and the spacing is r1; the spacing between Listening Position 4 and the point sound source A1 is r2, and r2<r1. Point sound source A1 and point sound source A2 respectively generate sound with opposite phases.

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

[0071] To increase the auditory volume, particularly the mid-to-low frequency range, while still maintaining the effect of canceling out sound leakage from the far field, a cavity structure may be installed around one of the dual-point sound sources. Figure 12 is an exemplary schematic distribution diagram of a case in which a cavity structure is installed around one of the dipole sound sources according to some embodiments of this specification. The “cavity structure” as used herein is a structure that is isolated from the outside and has a hollow interior, and the structure does not completely seal and block its interior from the outside, but has leakage structures (e.g., openings, gaps, conduits, etc.) that acoustically communicate with the external environment, forming a cavity-like structure and ensuring the characteristic of opening both ears. In some embodiments, the cavity structure may be equipped with leakage structures that can acoustically communicate the interior of the cavity structure with the external environment and ensure the opening of both ears. Exemplary leakage structures may include openings, gaps, conduits, etc., or any combination thereof.

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

[0073] Two sound sources with opposite phases form a dipole, each radiating sound into the surrounding space, causing a sound wave interference cancellation phenomenon and achieving a sound leakage cancellation effect. Because the difference in acoustic distance and volume difference between the two sound sources is large at the listening position, the sound cancellation effect is relatively less pronounced, and louder sound can be heard at the listening position than at other positions. To ensure the sound leakage cancellation effect and at the same time to increase the listening volume as much as possible, a cavity structure as shown in Figure 12 may be installed. As shown in Figure 12, when a cavity structure is installed between 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] Figure 13 is a schematic diagram illustrating the principle of a dipole sound source structure and a case in which a cavity structure is installed around one of the dipole sound sources, according to some embodiments of this specification.

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

[0076] To ensure sound leakage cancellation while simultaneously maximizing the listening volume, a cavity structure, as shown in Figure 12, may be installed around one of the two dipole sound sources. For listening, as shown in the upper right of Figure 13, since one of the sound sources A is enclosed in the cavity structure, most of the radiated sound reaches the listening position by direct or reflected light. In contrast, without the cavity structure, most of the sound radiated from the sound source does not reach the listening position. Therefore, by installing the cavity structure, the volume of sound reaching the listening position can be significantly increased. At the same time, only a small portion of the out-of-phase sound radiated from the out-of-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, and its intensity is significantly lower than that of sound source B and significantly lower than that of sound source A. The sound generated by secondary sound source B' exhibits a weak inverse phase cancellation effect with respect to sound source A within the cavity, which significantly increases the perceived volume at the listening position.

[0077] Regarding sound leakage, as shown in the lower right of Figure 13, the emission of sound from sound source A to the outside through the leakage structure of the cavity corresponds to the generation of a secondary sound source A' in the leakage structure. Almost all of the sound emitted from sound source A is output from the leakage structure, and since the structural scale of the cavity is much smaller (at least an order of magnitude smaller) than the spatial scale used to evaluate sound leakage, the intensity of secondary sound source A' is considered to be equivalent to that of sound source A. The sound cancellation effect generated by secondary sound source A' and sound source B with respect to the external space corresponds to the sound cancellation effect generated by sound source A and sound source B. In other words, this cavity structure still maintains a considerable sound leakage reduction effect.

[0078] Figure 14A is a schematic diagram of a monopole sound source according to some embodiments of this specification. Figure 14B is a schematic diagram of a dipole sound source according to some embodiments of this specification. Figure 14C is a schematic diagram of a case in which a baffle structure is installed around one of the sound sources of the dipole sound source according to some embodiments of this specification. Figure 14D is a schematic diagram of a case in which a cavity structure is installed around one of the sound sources of the dipole sound source according to some embodiments of this specification. Figure 15A is a frequency response characteristic curve diagram of the sound and sound leakage at the listening position of a monopole sound source according to some embodiments of this specification. Figure 15B is a frequency response characteristic curve diagram of the sound and sound leakage at the listening position of a dipole sound source according to some embodiments of this specification. Figure 15C is a frequency response characteristic curve diagram of the sound and sound leakage at the listening position when a baffle structure is installed around one of the sound sources of the dipole sound source according to some embodiments of this specification. Figure 15D is a frequency response characteristic curve diagram of the sound and sound leakage at the listening position when a cavity structure is installed around one of the dipole sound sources according to some embodiments of this specification.

[0079] Generally, a larger difference between the frequency response curve of the auditory volume and the frequency response curve of the sound leakage volume is desirable. As can be seen from Figures 15A to 15D, the scheme using a cavity structure clearly improves the auditory volume compared to other structures, while the sound leakage volume is comparable to that of other structures. This indicates that using a cavity structure minimizes sound leakage at the same auditory volume and maximizes auditory volume at the same sound leakage volume.

[0080] To more directly express the effect of this scheme, the reciprocal of the sound leakage index α, 1 / α, which may be called the auditory index, may be used as the effect of evaluating each structure. Its meaning is the magnitude of the auditory volume when the sound leakage is the same. From the viewpoint of application, a larger auditory index is preferable. Figure 16 is a schematic diagram of the auditory index in some embodiments of this specification, where a baffle structure is installed around a monopole sound source, a dipole sound source, one of the dipole sound sources, and a cavity structure is installed around one of the dipole sound sources. As shown in Figure 16, in terms of auditory index, the cavity structure can significantly increase the auditory volume, and therefore its auditory effect is significantly better than that of the other structures.

[0081] In some embodiments, the acoustic effect is related to the leakage structure in the cavity structure (e.g., openings, gaps, conduits, etc.), and the location of the leakage structure and the size of the opening will be described below.

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

[0083] Figure 18 is a diagram of auditory index curves for cavity structures with leak structures of different sizes according to some embodiments of this specification. As shown in Figure 18, while keeping the relative distance from the opening to the centroid constant (e.g., L / d0 = 1.09), the auditory index decreases as the relative opening size S / S0 increases. This is because a larger relative opening results in more sound components being directly radiated outward from the contained sound source, and less sound reaching the listening position. As a result, the auditory volume decreases with increasing relative opening, and consequently, the auditory index decreases.

[0084] Figure 19 is a diagram of auditory index curves for cavity structures having leakage structures at different locations according to some embodiments of this specification. As shown in Figure 19, the larger the relative distance L / d0 from the opening to the centroid, while keeping the relative opening size (e.g., S / S0 = 0.06) constant, the smaller the auditory index. This is because, as the relative distance increases, the distance between the secondary sound source A' and sound source B generated at the opening increases, weakening the inverse phase cancellation effect of the sounds generated by both in the external sound field, resulting in greater sound leakage and, consequently, a decrease in the auditory index.

[0085] Figure 20A is an auditory index curve diagram at 500 Hz for cavity structures having leak structures of different locations and sizes according to some embodiments of this specification. Figure 20B is an auditory index curve diagram at 1000 Hz for cavity structures having leak structures of different locations and sizes according to some embodiments of this specification. Figure 20C is an auditory index curve diagram at 2000 Hz for cavity structures having leak structures of different locations and sizes according to some embodiments of this specification. Figure 20D is an auditory index curve diagram at 5000 Hz for cavity structures having leak structures of different locations and sizes according to some embodiments of this specification. Considering the relative area S / S0 of the opening of the leak structure and the relative distance L / d0 from the centroid of the opening to the external sound source, in some embodiments, in order to ensure that the auditory index is higher than that of a dipole in the main frequency band of the sound (for example, the frequency band of 5000 Hz or below 10 kHz), the relative area S / S0 of the opening of the leak 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 example of a single-opening leakage structure is merely one example; a cavity structure leakage structure can include one or more openings, achieving a superior auditory index, and particularly improving the auditory index at high frequencies. Using a structure with two openings as an example, the cases of equal opening and equal opening ratio are analyzed below. Comparing this to a structure with only one opening, "equal opening" here means installing two openings of the same dimensions as the structure with only one opening, and "equal opening ratio" means that the sum of the opening areas S / S0 of the two installed openings is the same as the structure with only one opening. Equal opening corresponds to a 1x enlargement of the relative opening size S / S0 of the structure with only one opening, and as mentioned earlier, the overall auditory index decreases. In the case of equal opening ratio, even if S / S0 is the same as the structure with only one opening, the distance from the two openings to the external sound source is different, resulting in a different auditory index.

[0087] In some embodiments, when the line connecting the two openings forms a different angle with respect to the line connecting the two sound sources, it results in a difference in the position of the secondary sound sources formed in the openings, further affecting the sound leakage reduction effect. Figure 21A is a schematic diagram of a cavity structure having two horizontal openings according to some embodiments of this specification. Figure 21B is a schematic diagram of a cavity structure having two vertical openings according to some embodiments of this specification. As shown in Figure 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 sources are the maximum and minimum, respectively. As shown in Figure 21B, when the lines connecting the two openings are perpendicular (i.e., two vertical openings), the distances from the two openings to the external sound sources are equal and take an intermediate value.

[0088] Figure 22 is a comparison of the auditory index curves of a cavity structure with two openings and a cavity structure with one opening, according to some embodiments of this specification. As shown in Figure 22, the auditory index of a cavity structure with equal openings is generally lower than that of a cavity structure with one opening. The difference in distance from the two openings to the external sound source results in a different auditory index for a cavity structure with equal openings. As shown in Figures 21A, 21B, and 22, the auditory index of a leakage structure with equal openings is higher than that of a leakage structure with equal openings, whether horizontal or vertical. This is because the relative opening size S / S0 of a leakage structure with equal openings is reduced to 1x compared to a leakage structure with equal openings, resulting in a higher auditory index. As shown in Figures 21A, 21B, and 22, the auditory index for horizontal openings is higher for both leakage structures with equal openings and leakage structures with equal openings. This is because, in a horizontal opening leakage structure, 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 thus formed secondary sound source and the external sound source is closer to the original two sound sources, resulting in a higher auditory index and further improving the sound leakage reduction effect. 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] Figure 23A is a schematic diagram of a cavity structure having one opening according to some embodiments of this specification. Figure 23B is a schematic diagram of a cavity structure having two openings according to some embodiments of this specification. Figure 23C is a schematic diagram of a cavity structure having three openings according to some embodiments of this specification. Figure 23D is a schematic diagram of a cavity structure having four openings according to some embodiments of this specification.

[0090] Figure 24 is a comparative diagram of auditory index curves for cavity structures with different numbers of openings according to some embodiments of this specification. As shown in Figure 24, cavity structures using multiple openings can better improve the resonant frequency of aeration sound within the cavity structure compared to a cavity structure with one opening, thereby giving the entire device a better auditory index in the high-frequency range (e.g., sounds with frequencies close to 10,000 Hz) compared to a cavity structure with only one opening. The need for sound leakage reduction is greater in the high-frequency range because the human ear is more sensitive to this range. Therefore, a cavity structure with more than one opening may be selected to improve the sound leakage reduction effect in the high-frequency range.

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

[0092] Figure 25B is a comparative diagram of auditory index curves for different relative volumes of a cavity structure having a single opening, according to several embodiments of this specification. As shown in Figure 25B, compared to a dual-point sound source (dipole) without a cavity structure, the larger the relative volume V / V0 of the cavity structure, the larger the auditory index in the low-frequency range (e.g., frequencies below 500 Hz) and the smaller the auditory index in the high-frequency range (e.g., frequencies above 500 Hz). Overall, the larger the relative volume V / V0 of the cavity structure, the smaller the auditory index overall. This is because, due to the influence of aerial resonance within the cavity structure, aerial noise is generated within the cavity structure at the resonant frequency of the cavity structure, radiating sound outward at a much louder volume than the external sound source, resulting in a significant improvement in sound leakage, and furthermore, the auditory index becomes remarkably smaller near the resonant frequency. As shown in Figure 25B, the remarkably small auditory index near the resonant frequency appears as a deep dip in the frequency response curve. If the dimensions of the opening remain constant, the larger the relative volume of the cavity structure, the lower the resonant frequency and the deeper the resulting deep dip. As shown in Figure 25B, by setting the relative volume V / V0 of the cavity structure to reduce the effect of the dip in the auditory index and to make the auditory index in most frequency bands higher than that of a dipole sound source without a cavity structure, the resonant frequency is shifted to the highest possible frequency, satisfying a certain condition, for example, that it is 7000 Hz or higher. 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 audible and sound leakage effects are related to the volume of the sound source. Figure 26A is a schematic diagram of a cavity structure having one opening according to some embodiments of this specification. As shown in Figure 26A, the volume of the two sound sources is characterized by testing the effective sound pressure values ​​PA and PB generated by the two sound sources at positions equal to the distance from sound sources A and B, and the sound pressure ratio of the two sound sources is set to Nsource = PB / PA. Note that calibrating the volume of the sound source using the effective sound pressure values ​​PA and PB is merely one example, and the volume of the sound source may be calibrated using other methods.

[0094] Figure 26B is a comparative diagram of the auditory index of cavity structures having different sound pressure ratio (Nsource) values ​​according to some embodiments of this specification. As shown in Figure 26B, when the relative opening size (e.g., S / S0 = 0.09) is kept constant and the Nsource value is small, the suppression of internal sound within the cavity structure is insufficient. This results in an increase in the auditory volume within the cavity structure, especially at high frequencies (e.g., above 5000 Hz), leading to an improvement in the auditory index at high frequencies. In the low-frequency band (e.g., below 1000 Hz), the volume of sound source B is low, making it difficult to form an ideal dipole sound field distribution. As a result, the inverse phase cancellation effect against sound leakage from sound source A weakens, leading to increased sound leakage and a decrease in the auditory index at low frequencies.

[0095] When Nsource is close to 1, more sound from sound source B enters the cavity structure, particularly weakening the audible volume at high frequencies (e.g., above 5000Hz). As a result, the audible figure at high frequencies is lower than when sound leakage is low relative to Nsource. In the mid-to-low frequency range (e.g., below 1000Hz), sound sources A and B are closer together due to an ideal dipole sound field distribution, reducing overall sound leakage and significantly improving the audible figure, making the audible figure ideal across the entire frequency range.

[0096] When Nsource is greater than 1, the sound leaking from sound source A is less likely to suppress the sound generated from sound source B in opposite phase, increasing sound leakage within the cavity structure. Furthermore, the overall auditory index decreases, and the auditory volume increases sharply due to aeration resonance only in the frequency band around the resonant frequency of the cavity structure (e.g., around 2000 Hz), and the auditory index also increases sharply in that frequency band.

[0097] Figure 27A is an auditory index curve diagram at a frequency of 20 Hz for the cavity structure shown in Figure 26A, according to some embodiments of this specification, when the cavity structure has a different size of leakage structure and a different sound pressure ratio Nsource. Figure 27B is an auditory index curve diagram at a frequency of 100 Hz for the cavity structure shown in Figure 26A, according to some embodiments of this specification, when the cavity structure has a different size of leakage structure and a different sound pressure ratio Nsource. Figure 27C is an auditory index curve diagram at a frequency of 1000 Hz for the cavity structure shown in Figure 26A, according to some embodiments of this specification, when the cavity structure has a different size of leakage structure and a different sound pressure ratio Nsource. Figure 27D is an auditory index curve diagram at a frequency of 10000 Hz for the cavity structure shown in Figure 26A, according to some embodiments of this specification, when the cavity structure has a different size of leakage structure and a different sound pressure ratio Nsource.

[0098] Figure 28A is a schematic diagram of a cavity structure having one opening according to some embodiments of this specification. Figure 28B is a auditory index curve diagram at a frequency of 20 Hz for the cavity structure shown in Figure 28A, according to some embodiments of this specification, when the cavity structure shown in Figure 28A has a leak structure of a different size and a different sound pressure ratio Nsource. Figure 28C is a auditory index curve diagram at a frequency of 100 Hz for the cavity structure shown in Figure 28A, according to some embodiments of this specification, when the cavity structure shown in Figure 28A has a leak structure of a different size and a different sound pressure ratio Nsource. Figure 28D is a auditory index curve diagram at a frequency of 1000 Hz for the cavity structure shown in Figure 28A, according to some embodiments of this specification, when the cavity structure shown in Figure 28A has a leak structure of a different size and a different sound pressure ratio Nsource. Figure 28E is an auditory index curve diagram at a frequency of 10000 Hz for the cavity structure shown in Figure 28A, according to some embodiments of this specification, when the cavity structure shown in Figure 28A has a leak structure of a different size and a different sound pressure ratio Nsource.

[0099] Figure 29A is a schematic diagram of a cavity structure having one opening according to some embodiments of this specification. Figure 29B is an auditory index curve diagram at a frequency of 20 Hz for the cavity structure shown in Figure 29A, according to some embodiments of this specification, when the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). Figure 29C is an auditory index curve diagram at a frequency of 100 Hz for the cavity structure shown in Figure 29A, according to some embodiments of this specification, when the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). Figure 29D is an auditory index curve diagram at a frequency of 1000 Hz for the cavity structure shown in Figure 29A, according to some embodiments of this specification, when the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource). Figure 29E is an auditory index curve diagram at a frequency of 10000 Hz for the cavity structure shown in Figure 29A, according to some embodiments of this specification, when the cavity structure has different sizes of leakage structures and different sound pressure ratios (Nsource).

[0100] The difference between the cavity structures with one opening shown in Figures 26A, 28A, and 29A is that they have a relative distance L / d0 from the centroid of the different openings to the external sound source. In Figure 26A, the center of the cavity structure, the centroid of the opening of the leak structure, and the sound source located outside the cavity structure are on a straight line with no shielding between the two sound sources. In Figure 28A, the line connecting the center of the cavity structure and the centroid of the opening of the leak structure is perpendicular to the line connecting the two sound sources. In Figure 29A, the center of the cavity structure, the centroid of the opening of the leak structure, and the sound source located outside the cavity structure are on a straight line with shielding between the two sound sources through the cavity structure. As shown in Figures 27A to 27D, 28B to 28E, and 29B to 29E, in order to ensure that a dual-point sound source with a cavity structure installed has a higher auditory index within the frequency range audible to the human ear compared to a dual-point sound source structure without a cavity structure, when the relative area S / S0 of the openings is 0.075 or less, 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 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 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 volume of the two sound sources may be adjusted by directly adjusting and controlling the output power of the two sound sources. In some embodiments, the difference in volume of the two sound sources may be achieved by a specific acoustic structure. Exemplary acoustic structures may include slits, conduits, cavities, gauze, porous media, 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 channel, thereby increasing the volume of the sound source at a specific frequency. Alternatively, for example, a porous media may be placed between one of the sound sources and the listening position to reduce the volume of the sound source.

[0102] Figure 30 is a block diagram of an exemplary open-type earphone 100 according to some embodiments of this specification. As shown in Figure 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 with opposite phases. The housing 120 houses the acoustic driver 110. The suspension structure 130 fixes the housing 120 near the user's ear in a position that does not obstruct the user's ear canal. In some embodiments, the housing 120 may include a body 121 and a baffle 122. The main body 121 defines a first cavity for housing the acoustic driver 110, and the baffle 122 is connected to the main body 121 and extends toward the user's ear canal, defining a second cavity together with the user's auricle (similar to the cavity structure shown in Figures 12, 13, 14D, 17, 21A-21B, 23A-23D, 25A, 26A, 28A, or 29A). For a description of the acoustic driver 110, housing 120, and suspension structure 130, refer to Figure 1 or 31 of this specification.

[0103] Hereinafter, various embodiments of open-type earphones will be illustrated with reference to Figures 31 to 44.

[0104] Figure 31 is a schematic diagram of an exemplary open-type earphone 100 according to some embodiments of this specification. As shown in Figure 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, without obstructing the user's ear canal. For example, the housing 120 may be fixed in front of the user's tragus and be in close contact with the person's face. Alternatively, for example, one end of the housing 120 (for example, the end away from the suspension structure 130) may be in contact with the inside of the user's auricle (for example, in the concha cavity, above the antihelix, etc.). The acoustic driver 110 may generate two sounds with opposite phases. 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 main body 121 may define a first cavity for housing the acoustic driver 110. In some embodiments, the main body 121 may have a regular shape such as a rectangle, square, cylinder, ellipse, or sphere, or any irregular shape. The baffle 122 may be connected to the side of the main body 121 away from the user's face. For example, the baffle 122 may be connected to the surface of the main body 121 opposite the face-contact surface of the main body 121 that is in contact with the face, so as to avoid collision with the tragus. The baffle 122 may form a second cavity together with the user's auricle. In some embodiments, the housing 120 may be provided with a first sound vent 123 and a second sound vent 124 that are conductive to the first cavity, each emitting two sound signals with opposite phases generated by the acoustic driver 110. In some embodiments, as described in the relevant section of Figure 12, in order to increase the listening volume of the open-type earphone 100, particularly the listening volume of mid-to-low frequencies, while still maintaining the effect of canceling out sound leakage from the far field, a second cavity is used to separate two sound vents, so that one of the sound vents is located inside the second cavity and the other sound vent is located outside the second cavity.For example, as shown in Figure 31, the first sound vent 123 is located inside the second cavity, and the second sound vent 124 is located outside the second cavity. For example, the first sound vent 123 may be located in the cross-section where the main body 121 and the baffle 122 intersect (for example, shown in Figure 32), and the second sound vent 124 may be located on any surface outside the second cavity of the main body 121 (for example, the side that is familiar to a person's face as shown in Figure 31, or a surface parallel to the side of the main body 121 where the first sound vent 123 is located). Note that the sound vent 123 is not visible from the angle shown in Figure 31, and the number 123 only indicates the relative position of the plane in which the first sound vent is located, and the main body 121 and baffle 122. In some embodiments, the sound vent located inside the second cavity (i.e., the first sound vent 123) may be located between the user's ear canal and the sound vent located outside the second cavity (i.e., the second sound vent 124).

[0105] In some embodiments, the first sound vent 123 may be located in the cross-section where the main body 121 and the baffle 122 intersect (for example, as shown in Figure 32), and the second sound vent 124 may be located on the side of the main body 121 away from the face, and the first sound vent 123 may be located closer to the user's ear canal than the second sound vent 124, so that the first sound vent 123 is located inside the second cavity and the second sound vent 124 is located outside the second cavity. In some embodiments, the first sound vent 123 may be located close to the baffle 122. If the baffle 122 is part of the main body 121, the first sound vent 123 may be located on the baffle 122. In some embodiments, the first sound vent 123 may be located between the user's ear canal and the second sound vent 124. In some embodiments, the first sound vents 123 and the second sound vents 124 may be distributed diagonally on the side of the main body 121 facing the face. However, the first sound vents 123 and the second sound vents 124 are not limited to being distributed diagonally as shown in Figure 31, but may be distributed along the side of the main body 121 facing the face, or in any other arbitrary distribution method.

[0106] Figure 32 is a schematic diagram of an exemplary housing 120 according to some embodiments of this specification. In some embodiments, the body 121 may be located anterior to the tragus or located within the auricle (with overlap between the body 121 and the auricle projection plane), and the baffle 122 may be connected to the side of the body 121 away from the user's face and extend toward the external auditory canal relative to the body 121. In some embodiments, the baffle 122 may be a plate-like structure, and the thickness of the baffle 122 may be less than the thickness of the body 121, as the body 121 defines a first cavity for housing the acoustic driver 110. As shown in Figure 32, the thickness t2 of the baffle 122 may be less than the thickness t1 of the body 121. In some embodiments, when the body 121 is located anterior to the tragus, the thickness of the body 121 is the distance between the side of the body 121 closest to the face and the side of the body 121 furthest from the face, and the thickness of the baffle 122 may be the distance between two sides of the body 121 parallel to the two sides. In some embodiments, when the body 121 is located within the auricle or overlaps with the auricle projection plane, the thickness of the body 121 is the distance between the side of the body 121 closest to the auricle and the side of the body 121 furthest from the auricle, and the thickness of the baffle 122 may be the distance between two sides of the body 121 parallel to the two sides. 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. In this specification, the projection plane is the projection of an object onto the head. For example, the projection surface of the main body 121 overlapping with the projection surface of the auricle means that the projection surface of the main body 121 on the head overlaps with the projection surface of the auricle on the head, and for example, the projection surface of the main body 121 is completely located within the range of the projection surface of the auricle.

[0107] In some embodiments, as shown in Figures 20A to 20D and their related descriptions, in order to improve the auditory index and make the auditory index at each frequency greater than that of a dual-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 Figure 31, when the user is wearing open-type earphones 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 the ratio of the distance L from the boundary 1221 (shown in Figure 31) of the baffle 122 close to the user's ear canal to the second sound outlet 124 and the distance d0 between the two sound outlets. Here, "the distance from boundary 1221 to the second sound vent 124" is the distance between the midpoint (for example, the midpoint M of the line segment m shown in Figure 31) of the line connecting the two endpoints that abut the auricle at the boundary line or interface of the baffle 122 that is close to the ear canal (for example, the line segment m shown in Figure 31) and the second sound vent 124. In some embodiments, the ratio of the distance from the boundary 1221 of the baffle 122 that is close to the user's ear canal to the second sound vent 124 to the distance between the two sound vents may be less than 1.78. As just one example, the ratio of the distance from the boundary 1221 of the baffle 122 that is close to the user's ear canal to the second sound vent 124 to the distance between the two sound vents 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, as shown in Figure 22 and its related description, 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 in order to bring 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 to improve the sound leakage reduction effect. When the user is wearing open-type earphones 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 outlet 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 outlet 124 may be smaller than the distance between the two sound outlets (i.e., the first sound outlet 123 and the second sound outlet 124).

[0109] In some embodiments, as shown in Figures 25A to 25B and their related descriptions, the relative volume V / V0 of the cavity structure (i.e., the second cavity) may be less than 1.75 in order to improve the overall auditory index. The relative volume V / V0 of the cavity structure (i.e., the second cavity) may be expressed as the ratio of the volume of the second cavity to the reference volume. For example, the ratio of the volume of the second cavity to the reference volume may be less than 1.75. When the user is wearing the open-type earphone 100, the reference volume may be the cube of the distance from the boundary 1221 adjacent to the user's ear canal to the sound outlet (i.e., the second sound outlet 124) located outside the second cavity. In some embodiments, the volume of the second cavity may be the volume of a sealed space enclosed together by the concha, the ear canal, the housing 120, the sound outlet, and a curved surface enclosed by a gap through which sound leaks. Therefore, the volume of the second cavity can be measured using a gel injection mold for the ear. In some embodiments, the volume of the second cavity may be the product of the distance from the surface of the housing 120 facing the auricle / conchae cavity to the surface of the auricle / conchae cavity and the area enclosed by each contact point between the auricle and the housing 120. The distance from the surface of the housing 120 facing the auricle / conchae cavity to the surface of the auricle / conchae cavity may be the distance to the surface of the auricle / conchae cavity along the normal direction of the sound vent (e.g., the first sound vent 123) located inside the second cavity of the housing 120. Each contact point between the auricle and the housing 120 may include the contact points between the upper and lower edges of the housing 120 (e.g., two edges along the vertical axis of the human body) and the auricle, the contact point between the end of the housing 120 (e.g., one end away from the suspension structure 130) and the conchae cavity, the end of the housing 120 closest to the wall of the conchae cavity, or any combination thereof.

[0110] In some embodiments, as shown in Figures 27A to 27D, 28B to 28E, and 29B to 29E and their related descriptions, in a dual-point sound source where a cavity structure (i.e., a second cavity) is installed, the relative distance L / d0 from the centroids of different openings to the external sound source, and the relative area S / S0 of the different openings, the value of the sound pressure ratio Nsource of the two sound sources may be in the range of 0.2 to 2.0 in order to ensure that both have a higher auditory index within the frequency range audible to the human ear compared to a dual-point sound source structure without a cavity structure. For example, the ratio of the volume (or sound pressure) of the sound derived from a sound outlet located outside the second cavity (e.g., a second sound outlet 124) to the volume (or sound pressure) of the sound derived from a sound outlet located inside the second cavity (e.g., a first sound outlet 123) is in the range of 0.2 to 2.0. As a mere example, the range of the ratio between the volume of sound derived from the second sound hole 124 and the volume of sound derived from the first sound hole 123 may be 0.6 to 1.4. Alternatively, for example, the range of the ratio between the volume of sound derived from the second sound hole 124 and the volume of sound derived from the first sound hole 123 may be 0.7 to 1.3.

[0111] In some embodiments, the volume of sound emitted from the first sound outlet 123 and the second sound outlet 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 within the first cavity corresponding to the first sound outlet 123 and the second sound outlet 124, and the two sound signals with opposite phases output by the acoustic driver 110 are emitted through the first sound outlet 123 and the second sound outlet 124, respectively, by the acoustic structures, and the acoustic structures can adjust the ratio between the volume of sound emitted from the sound outlet located outside the second cavity (i.e., the second sound outlet 124) and the volume of sound emitted from the sound outlet located inside the second cavity (i.e., the first sound outlet 123). Exemplary acoustic structures may include slits, conduits, cavities, gauze, porous media, or any combination thereof.

[0112] In some embodiments, the suspension structure 130 may be an arc-shaped structure that conforms to the user's auricle so that it is suspended from the user's upper auricle. In some embodiments, the suspension structure 130 may be a clamping structure that conforms to the user's auricle so that it is clamped onto the user's auricle. In some embodiments, one end of the suspension structure 130 away from the auricle may be connected to the housing 120, and the other end may extend along the user's auricle.

[0113] Figure 33 is a schematic diagram of an exemplary housing 120 according to some embodiments of this specification. As shown in Figure 33, the main body 121 may be located in front of the user's tragus, and the baffle 122 may be installed so as to protrude from the main body 121 in the lateral direction or in the longitudinal direction. Here, "lateral direction" is the direction along the sagittal axis of the human body, and "longitudinal direction" is the direction along the vertical axis of the human body. The portion of the baffle 122 that protrudes from the main body 121 in the longitudinal direction has a longitudinal extension dimension (dimension a shown in Figure 33), and the portion of the baffle 122 that protrudes from the main body 121 in the lateral direction has a lateral extension dimension (dimension b shown in Figure 33).

[0114] Figure 34A shows the sound field of an open-type earphone without a baffle. Figure 34B shows the sound field of an open-type earphone with a baffle as shown in Figure 33. As shown in Figure 34A, when the baffle 122 is absent, the sound pressure is concentrated and distributed around the acoustic driver 110 (which can also be called the main body 121). As shown in Figure 34B, when the baffle 122 is present, the baffle 122, along with a portion of the auricle, surrounds the second cavity, and the gap between the auricle (e.g., the ear 101 shown in Figure 34B) and the baffle (e.g., the gap 3401 shown in Figure 34B) may approximate a leakage structure that forms the second cavity. Since the sound A emanated from the first sound outlet 123 inside the second cavity and the sound B emanated from the second sound outlet 124 outside the second cavity are in opposite phases, sound A leaks through the leakage structure and cancels out sound B in opposite phase, ensuring the normal operation of the sound leakage reduction mechanism of the open-type earphone 100. At the same time, the presence of the second cavity can alter the sound pressure distribution within the auricle, causing the sound pressure to concentrate on the baffle 122. At least a portion of the external auditory canal opening overlaps with the projection plane of the baffle 122, thereby significantly increasing the sound pressure at the external auditory canal opening. Consequently, the presence of the second cavity alters the sound pressure distribution within the auricle, increasing the sound pressure at the external auditory canal opening, significantly increasing the perceived volume, and improving the auditory index.

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

[0116] In some embodiments, the dimensions of the baffle 122 (for example, the longitudinal and lateral extension dimensions of the baffle 122 shown in Figure 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 longitudinal and lateral extension dimensions of the baffle 122. Figure 37A is a diagram showing the change in listening volume for different lateral and longitudinal extension dimensions of the baffle 122 shown in Figure 33 when the frequency is 500 Hz. Figure 37B is a diagram showing the change in listening volume for different lateral and longitudinal extension dimensions of the baffle 122 shown in Figure 33 when the frequency is 1000 Hz. Figure 37C is a diagram showing the change in sound leakage volume for different lateral and longitudinal extension dimensions of the baffle 122 shown in Figure 33 when the frequency is 500 Hz. Figure 37D is a diagram showing the change in sound leakage volume for different lateral and vertical extension dimensions of the baffle 122 shown in Figure 33, when the frequency is 1000 Hz. As shown in Figures 37A to 37D, when the lateral extension b of the baffle 122 varies within the range of 2 mm to 22 mm and the vertical extension a varies within the range of 2 mm to 10 mm, the open-type earphone 100 shows a maximum increase in listening volume of approximately 8 dB and a maximum increase in sound leakage volume of approximately 3 dB. This indicates that the listening index of the open-type earphone 100 can always be improved when the lateral extension of the baffle 122 is within the range of 2 mm to 22 mm and the vertical extension is within the range of 2 mm to 10 mm. Therefore, in some embodiments, the vertical extension of the baffle 122 may be within the range of 2 mm to 10 mm. For example, the vertical extension of the baffle 122 may be within the range of 3 mm to 9 mm. For example, the vertical extension dimension of the baffle 122 may be in the range of 4 mm to 8 mm. In some embodiments, the lateral extension dimension of the baffle 122 may be in the range of 2 mm to 22 mm. For example, the lateral extension dimension of the baffle 122 may be in the range of 4 mm to 20 mm. For example, the lateral extension dimension of the baffle 122 may be in the range of 6 mm to 18 mm.

[0117] The vertically extending dimension and the horizontally extending dimension of the baffle 122 can form an effective area of the baffle 122. The "effective area" herein refers to the area of a portion of the baffle 122 that forms a second cavity together with the auricle (for example, the area of the hatched portion shown in FIG. 33). In some embodiments, the effective area of the baffle 122 is 70 mm 2 ~1110 mm 2 may be within the range of . For example, the effective area of the baffle 122 is 84 mm 2 ~1060 mm 2 may be within the range of . For another example, the effective area of the baffle 122 is 100 mm 2 ~900 mm 2 may be within the range of .

[0118] In some embodiments, the main body 121 and the baffle 122 may be of an integrated structure, and the baffle 122 is a part of the housing 120 extending toward the user's external auditory canal and is disposed to be close to the face. In some embodiments, the main body 121 and the baffle 122 are separate structures and may be assembled together. In some embodiments, the baffle 122 may be a side surface of the main body 121 (for example, a side surface of the main body 121 facing the user's face).

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

[0120] Figure 38 is a schematic diagram of an exemplary open-type earphone 100 according to some embodiments of this specification. As shown in Figure 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 body 121 and a baffle 122, the body 121 overlapping the auricle projection plane, and the baffle 122 positioned on the side of the body 121 adjacent to the external auditory canal and may overlap the auricle projection plane. In some embodiments, part of the body 121 may be located inside the auricle (for example, located in the superior auricle as shown in Figure 38). In some embodiments, part of the body 121 may be located in the inferior auricle. In some embodiments, the body 121 may be positioned to cover the tragus. In some embodiments, one of the two sound vents (e.g., the first sound vent 123) may be located on the side of the body 121 closest to the ear canal, and the other sound vent (e.g., the second sound vent 124) may be located on the side of the body 121 away from the ear canal, so that the first sound vent 123 is inside the second cavity and the second sound vent 124 is outside the second cavity.

[0121] In some embodiments, when the main body 121 is located inside the auricle or overlaps with the auricle projection surface, the effective area of ​​the baffle 122 is 15 mm² in order to improve the listening volume of the open-type earphone 100. 2 It may be greater than this. For example, the effective area of ​​baffle 122 is 20 mm². 2 The above is also acceptable. In some embodiments, when the main body 121 is located inside the auricle or overlaps with the auricle projection plane, and the main body 121 and baffle 122 are arranged along the vertical direction (as shown in Figure 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] Figure 39 is a comparison of the frequency response curves of an exemplary open-type earphone 100 according to some embodiments of this specification, with and without a baffle. As shown in Figure 39, curve 381 is when the vertical extension dimension is 1 cm (or 1 cm or more, or when the effective area of ​​the baffle 122 is 20 mm) 2 The above curves show the auditory frequency response curve of the open-type earphone 100 when the baffle 122 is installed, and curve 382 shows the auditory 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 auditory index of the open-type earphone 100 with the baffle 122 installed can be improved by 5 dB or more compared to the case when the baffle 122 is not installed.

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

[0124] As shown in Figures 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 the overall 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 (for example, the side away from the suspension structure 130) abuts against the user's auricle (for example, abuts into the concha 103, and as shown in Figure 42, the housing 120 abuts against the edge 1031 of the concha 103). The housing 120 together with the auricle (for example, the concha 103) defines a second cavity. For example, as shown in Figure 42, the auricle-facing surface of the housing 120 can define a second cavity together with the concha 103. Furthermore, as shown in Figures 45-46 or 47-48, the housing 120 may also include a first bent portion 127 and a second bent portion 128. In some embodiments, the auricle-facing surfaces of the first bent portion 127 and the second bent portion 128 may define a second cavity together with the concha. In some embodiments, the second bent portion 128 may define a second cavity together with the concha. The inclusion of the first bent portion 127 allows the open-type earphone 100 to conform well to the shape of the ear during the wearing process and to bypass the anterior side of the helix crus or the tragus. Simultaneously, the placement of the first bent portion 127 allows the second bent portion 128 to fit more snugly into the user's concha, and by bringing the end of the second bent portion 128 into contact with the edge or interior of the user's concha, the surface of the first bent portion 127 facing the auricle can form a more "complete" second cavity together with the concha, and the volume of the formed second cavity becomes smaller (i.e., the second cavity has a smaller relative volume V / V0, further improving the overall auditory index), and it can better enclose the first sound outlet and the ear canal opening. Furthermore, the placement of the first bent portion 127 allows the center of gravity of the entire housing 120 to be closer to the ear base cross-section, making the open-type earphone 100 more stable when worn.Here, the "ear base cross-section" refers to the plane where the ear base intersects with the user's head, and the "center of gravity of the housing 120" is the overall center of gravity, including the weight of all the internal structures of the housing 120 (e.g., acoustic driver 110, core, battery, etc.) and the housing 120 itself.

[0125] In some embodiments, the first bent portion 127 and the second bent portion 128 may form the housing 120 by integral molding. In some other embodiments, the first bent portion 127 and the second bent portion 128 may be integrally connected by means of insertion, locking, etc., to form the housing 120. In some embodiments, the angle between the first bent portion 127 and the second bent portion 128 may be 90 degrees or more. Here, "angle between the bent portion" is the 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 angle between the first bent portion 127 and the second bent portion 128 γ may be 90 degrees. For example, as shown in Figures 47 to 48, the angle between the first bent portion 127 and the second bent portion 128 may be an obtuse angle. The angle between the first bent portion 127 and the second bent portion 128 shown in Figures 45 to 48 may be any angle that can form a second cavity together with the conchaecular cavity, and is not limited thereto. The gap between the housing 120 and the external auditory canal opening 102 may be a leak structure for the second cavity. By bringing the end of the housing 120 into contact with the edge or inside of the user's conchaecular cavity, the surface of the housing 120 facing the auricle can form a more "complete" second cavity together with the conchaecular cavity, and the volume of the formed second cavity becomes smaller (i.e., the second cavity has a smaller relative volume V / V0, further improving the overall auditory index), and it can better enclose the first sound outlet and the external auditory canal opening.

[0126] In some embodiments, in order to bring one end of the housing 120 (for example, the side away from the suspension 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 suspension structure 130 and the housing 120 is in the range of 100° to 150°, as shown in Figure 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 suspension structure 130 and the housing 120 is in the range of 120° to 140°.

[0127] In some embodiments, when the majority of users are wearing open-type earphones 100, 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 in order to allow the housing 120 to be inserted into the concha and form a second cavity with high acoustic effect (e.g., a small relative opening S / S0 of the second cavity). As shown in Figure 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 expressed 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 housing 120 has a length along its long axis on a surface away from the user's ear, ranging from 20 mm to 30 mm. As shown in Figure 40, the length along its long axis on a surface away from the user's ear may be denoted as 'a'. In some embodiments, the housing 120 has a length along its short axis (which may also be called its height) ranging from 11 mm to 16 mm on a surface away from the user's ear. As shown in Figure 40, the length along its short axis on a surface away from the user's ear may be denoted as 'h'. In this specification, the "long axis" of the housing 120 is the direction in which the longest line segment connecting two points on the edge of the surface exists on the surface of the housing 120 facing the user's ear canal, and the "short axis" is the direction perpendicular to the long axis on the surface of the housing 120 facing the user's ear canal (shown in Figure 51).

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

[0129] In some embodiments, the sound vents located outside the second cavity (i.e., the second sound vents 124) may be positioned on the side of the housing 120 away from the concha. For example, as shown in Figure 43, the sound vents located outside the second cavity (i.e., the second sound vents 124) may be positioned on the side of the housing 120 facing the triangular fovea. Alternatively, as shown in Figure 44, for example, the sound vents located outside the second cavity (i.e., the second sound vents 124) may be positioned on the side of the housing 120 facing the earlobe. Furthermore, for example, the sound vents located outside the second cavity may include two or more sound vents, two of which are positioned on the side of the housing 120 facing the triangular fovea and the side of the housing 120 facing the earlobe.

[0130] In some embodiments, as shown in Figures 20A to 20D and their related descriptions, in order to improve the auditory index and make the auditory index at each frequency greater than that of a dual-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. When the user is wearing 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 external auditory canal opening 102 to the second sound outlet 124 to the distance between the two sound outlets. The distance from the gap between the housing 120 and the ear canal opening 102 to the second sound vent 124 may be the distance between the center point of the gap region (e.g., region 420 shown in Figure 42) formed between the surface of the housing 120 facing the earlobe (e.g., earlobe 105 shown in Figure 42) and the ear 101 (e.g., the center point 4201 of region 420 shown in Figure 42) and the second sound vent 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 vent 124 to the distance between the two sound vents may be less than 1.78. As a mere example, the ratio of the distance from the gap between the housing 120 and the external auditory canal opening 102 to the second sound vent 124 to the distance between the two sound vents 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, as shown in Figure 22 and its related description, 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 in order to bring the secondary sound source of the sound source located inside the cavity structure (i.e., the second cavity) closer to the sound source located outside the cavity structure (i.e., the second cavity) and improve the sound leakage reduction effect. When the user is wearing the open-type earphone 100 shown in Figures 40 to 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 outlet 124. In some embodiments, the distance from the gap between the housing 120 and the ear canal opening 102 to the second sound outlet 124 may be smaller than the distance between the two sound outlets (i.e., the first sound outlet 123 and the second sound outlet 124).

[0132] In some embodiments, as shown in Figures 25A to 25B and their related descriptions, the relative volume V / V0 of the cavity structure (i.e., the second cavity) may be less than 1.75 in order to improve the overall auditory index. The relative volume V / V0 of the cavity structure (i.e., the second cavity) may be expressed as the ratio of the volume of the second cavity to the reference volume. For example, the ratio of the volume of the second cavity to the reference volume may be less than 1.75. When the user is wearing the open-type earphone 100 shown in Figures 40 to 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 outlet (i.e., the second sound outlet 124) located outside the second cavity. In some embodiments, the volume of the second cavity may be the volume of the sealed space enclosed together by the concha, the ear canal, the housing 120, the sound outlet, and the curved surface enclosed by the gap through which sound leaks. Therefore, the volume of the second cavity can be measured using a gel injection mold for the ear. In some embodiments, the volume of the second cavity may be the product of the distance from the surface of the housing 120 facing the auricle / conchae cavity to the surface of the auricle / conchae cavity and the area enclosed by each contact point between the auricle and the housing 120. The distance from the surface of the housing 120 facing the auricle / conchae cavity to the surface of the auricle / conchae cavity may be the distance to the surface of the auricle / conchae cavity along the normal direction of the sound vent of the housing 120. Each contact point between the auricle and the housing 120 may include the contact points between the upper and lower edges of the housing 120 and the auricle, the contact points between the end of the housing 120 and the conchae cavity, the endpoint of the housing 120 closest to the wall of the conchae cavity, or any combination thereof.

[0133] In some embodiments, as shown in Figures 27A to 27D, 28B to 28E, and 29B to 29E and their related descriptions, in a dual-point sound source where a cavity structure (i.e., a second cavity) is installed, the relative distance L / d0 from the centroids of different openings to the external sound source, and the relative area S / S0 of the different openings, the value of the sound pressure ratio Nsource of the two sound sources may be in the range of 0.2 to 2.0 in order to ensure that both have a higher auditory index within the frequency range audible to the human ear compared to a dual-point sound source structure without a cavity structure. For example, the ratio of the volume (or sound pressure) of the sound derived from a sound outlet located outside the second cavity (e.g., a second sound outlet 124) to the volume (or sound pressure) of the sound derived from a sound outlet located inside the second cavity (e.g., a first sound outlet 123) is in the range of 0.2 to 2.0. As a mere example, the range of the ratio between the volume of sound derived from the second sound hole 124 and the volume of sound derived from the first sound hole 123 may be 0.6 to 1.4. Alternatively, for example, the range of the ratio between the volume of sound derived from the second sound hole 124 and the volume of sound derived from the first sound hole 123 may be 0.7 to 1.3.

[0134] Figure 49A is a schematic diagram of the fit of an exemplary open-type earphone according to some embodiments of this specification. Figure 49B is a schematic diagram of the ear portion according to some embodiments of this specification. Figure 49C is a schematic diagram of the ear portion according to some embodiments of this specification. Figure 50A is a schematic diagram of the fit of an exemplary open-type earphone according to some embodiments of this specification. Figure 50B is a schematic diagram of the fit of an exemplary open-type earphone according to some embodiments of this specification. Figure 50C is a schematic diagram of the ear portion according to some embodiments of this specification. In some embodiments, the user's ear canal may be considered the auditory position, and the ear canal faces the concha, and the area that the housing 120 covers the user's concha is 20 mm², so that the second cavity defined by the housing 120 and the concha encloses the auditory position (i.e., the ear canal) as much as possible. 2 ~130mm 2It may be within the range. In some embodiments, the area covered by the housing 120 to the user's concha canal may be measured by fitting the open-type earphone 100 to a standard ear (for example, a KB5000 / KB50001 human ear from GRAS Sound&Vibration GmbH of Denmark, or any ear conforming to the IEC 60318-7 standard). For example, if the housing 120 of the open-type earphone 100 is not in contact with the wall of the concha canal (as shown in Figure 49A), the area covered by the housing 120 to the user's concha canal may be the area of ​​a triangular region consisting of the two furthest contact points (contact points 491 and 492 shown in Figure 49B) where the housing 120 contacts the inner contour of the concha canal (the contour facing the person's face, the inner contour of the concha canal shown in Figure 49C), and the furthest end point of the housing 120 away from the face (furthest end point 493 shown in Figure 49B). For example, if the housing 120 of the open-type earphone 100 abuts against the wall of the concha (as shown in Figure 50A) or abuts against the auricle beyond the concha (as shown in Figure 50B), the area that the housing 120 covers the user's concha may be the area of ​​a triangular region consisting of the two furthest contact points (contact points 501 and 502 shown in Figure 50C) where the housing 120 contacts the inner contour of the concha (the contour facing the person's face), and the furthest end point (furthest end point 503 shown in Figure 50C) of the housing 120 that contacts the wall of the concha or the outer contour of the concha (the contour away from the person's face, shown in Figure 49C). Furthermore, when the user is wearing the open-type earphone 100, the housing 120 may be suspended without contacting the user. Therefore, the contact point between the housing 120 and the inner or outer contour of the concha of the ear may be the intersection of the projection of the housing 120 onto the user's concha of the ear and the inner or outer contour of the concha of the ear.

[0135] Figure 51 is a schematic diagram of the fitting of an exemplary open-type earphone according to some embodiments of this specification. In some embodiments, the housing 120 may cover at least a portion of the user's ear canal, as shown in Figure 51, in order for the second cavity to enclose 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, along the short axis of the housing 120, the lower edge 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, along the short axis of the housing 120, the overlap distance h1 between the lower edge of the housing 120 and the user's ear canal may be in the range of 1 mm to 7.5 mm. For example, as shown in Figure 51, if 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 external auditory canal may be in the range of 1 mm to 7.5 mm along the vertical axis of the human body (i.e., the minor axis of the housing 120). Also, for example, if 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 external auditory canal may be in the range of 1 mm to 7.5 mm along the minor axis of the housing 120.

[0136] In some embodiments, the volume of sound emitted from the first sound outlet 123 and the second sound outlet 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 within the first cavity corresponding to the first sound outlet 123 and the second sound outlet 124, and the two sound signals with opposite phases output by the acoustic driver 110 are emitted through the first sound outlet 123 and the second sound outlet 124, respectively, by the acoustic structures, and the acoustic structures can adjust the ratio between the volume of sound emitted from the sound outlet located outside the second cavity (i.e., the second sound outlet 124) and the volume of sound emitted from the sound outlet located inside the second cavity (i.e., the first sound outlet 123). Exemplary acoustic structures may include slits, conduits, cavities, gauze, porous media, or any combination thereof.

[0137] Figures 31 to 44 are for illustrative purposes only and do not limit the present invention. Those skilled in the art can make various changes and modifications based on the description herein. The beneficial effects that can be achieved will differ depending on the embodiment, and in different embodiments, the achievable beneficial effects may be one or more of the above, or any other achievable beneficial effects. For example, the housing 120 may be circular in shape and the entire structure may be located in the concha. Alternatively, for example, the housing 120 may be elliptical in shape, with one end abutting the concha and the other end located outside the auricle. This specification describes the case where there are two sound vents as an example, but the number of sound vents is not limited, and there may be two or more sound vents that derive sound generated by the acoustic driver. This specification describes the leakage structure as including only one opening, but the cavity structure (i.e., the second cavity) may include multiple openings.

[0138] Having explained the basic concepts above, it will be clear to those skilled in the art that the above detailed disclosures are merely examples and do not limit the present application. Although not explicitly stated 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 remain within the spirit and scope of the exemplary embodiments of the present application.

[0139] Furthermore, certain terms are used in this Application to describe the embodiments thereof. For example, “one embodiment,” “one embodiment,” and / or “several embodiments” mean certain features, structures, or characteristics relating to at least one embodiment of this Application. Therefore, it should be emphasized and understood that two or more references to “one embodiment,” “one embodiment,” or “one alternative embodiment” 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 this Application can be appropriately combined.

[0140] Furthermore, unless explicitly stated in the claims, the enumerated order, use of alphanumeric characters, or use of other names of the processing elements or sequences described herein does not limit the order of the procedures and methods of this application. While the above disclosure illustrates various examples that are currently considered useful embodiments of the invention, such details are for illustrative purposes only, and it should be understood that the attached claims are not limited to the disclosed embodiments, but rather are intended to cover all modifications and equivalent combinations that fall within the spirit and scope of the embodiments of this application. For example, the system assembly described above may be implemented by hardware devices, but may also be implemented by software-only solutions, 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 into a single embodiment, drawing, or description thereof for the purpose of simplifying the description of the disclosure and aiding in the understanding of embodiments of one or more inventions. However, such disclosure methods should not be interpreted as reflecting an intention that the subject matter of the present application requires more features than are enumerated in each claim. In fact, the features of an embodiment may be fewer than all the features of a single embodiment disclosed above.

[0142] In some embodiments, numbers are used to describe components and attributes, and it should be understood that in some examples, these numbers are modified by the modifiers “approximately,” “nearly,” or “substantial.” Unless otherwise specified, “approximately,” “nearly,” or “substantial” indicates that the numbers are allowed to vary by up to ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are all approximations that may vary depending on the characteristics required for the particular embodiment. In some embodiments, the numerical parameters should be treated with the specified number of significant figures and the usual place-keep method applied. In some embodiments of this application, the numerical ranges and parameters used to determine the range are approximations, but in specific embodiments, such numbers should be set as precisely as possible.

[0143] All patents, patent applications, published patent gazettes, and other materials such as articles, books, specifications, publications, and documents referenced herein are incorporated in their entirety by reference, with the exception of any prosecution history documents that are inconsistent with or contradict the content of this Application, and any documents that may limit the broadest scope of the claims of this Application (currently or later relating to this Application). In the event that any description, definition, and / or use of terminology in the appendices to this Application is inconsistent with or contradicts the content of this Application, the description, definition, and / or use of terminology in this Application shall prevail.

[0144] Finally, it should be understood that the embodiments in this application are merely for illustrating the principles of the embodiments. Other modifications may also be within the scope of this application. Therefore, alternative configurations of the embodiments in this application may be considered, not as limiting but as illustrative, to be consistent with the teachings of this application. Accordingly, the embodiments in this application are not limited to those explicitly 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 folding section 128 Second folding section 130 Suspension structure

Claims

1. An acoustic driver that generates two sounds with opposite phases, A housing that houses the aforementioned acoustic driver and is equipped with two sound emission holes that each emit the two sounds having opposite phases, A suspension structure comprising a suspension structure that causes one end of the housing, away from the suspension structure, to abut against the user's auricle, The housing defines a first cavity for housing the acoustic driver, One end of the housing, away from the suspension structure, abuts against the concha, and the housing and the concha define a second cavity. The two sound-emitting holes are located inside and outside the second cavity, respectively, in an open-type earphone.

2. The open-type earphone according to claim 1, characterized in that the distance from the gap between the housing and the ear canal opening to the sound vent located outside the second cavity is smaller than the distance between the two sound vents.

3. The open-type earphone according to claim 1, characterized in that the housing includes a first bent portion and a second bent portion, the surfaces of the first bent portion and the second bent portion facing the auricle define the second cavity together with the concha cavity, and the angle between the first bent portion and the second bent portion is 90° or more.

4. The open-type earphone according to claim 1, characterized in that the angle between the surface of the housing facing the triangular fossa and the tangent to the connection between the suspension structure and the housing is within the range of 100° to 150°.

5. The open-type earphone according to claim 1, characterized in that the two sound vents include a first sound vent and a second sound vent, the first sound vent and the second sound vent are located inside and outside the second cavity, respectively, and the first sound vent is positioned closer to the ear canal opening than the second sound vent.

6. The open-type earphone according to claim 5, characterized in that the distance between the first sound vent and the wall surface of the concha cavity is in the range of 4 mm to 10 mm along the coronal axis direction of the user.

7. The open-type earphone according to claim 5 or 6, characterized in that the minimum distance from the first sound-emitting hole to the upper or lower edge perpendicular to the short axis direction of the housing is within the range of 3 mm to 8 mm, along the short axis direction of the housing.

8. The open-type earphone according to claim 1, characterized in that the distance between the upper surface of the housing along the user's vertical axis and the point of the suspension structure that contacts the user's ear along the user's vertical axis is within the range of 10 mm to 20 mm.

9. The open-type earphone according to claim 1, characterized in that the ratio of the distance from the gap between the housing and the ear canal opening to the sound vent located outside the second cavity to the distance between the two sound vents is less than 1.

78.

10. The open-type earphone according to claim 1, characterized in that the ratio of the volume of the second cavity to the 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 the sound outlet located outside the second cavity.

11. The open-type earphone according to claim 1, characterized in that the ratio of the area of ​​the housing covering the user's ear canal to the area of ​​the ear canal is greater than 1 / 2.

12. The open-type earphone according to claim 1 or 11, characterized in that, along the short axis direction of the housing, the overlap distance between the lower edge of the housing and the user's ear canal is in the range of 1 mm to 7.5 mm.

13. The area of ​​the housing that covers the user's concha is 20 mm². ２ ~130mm ２ An open-type earphone according to claim 1, characterized in that it is within the range.

14. The open-type earphone according to claim 1, characterized in that the ratio of the volume of sound emitted from a sound outlet located outside the second cavity to the volume of sound emitted from a sound outlet located inside the second cavity is within the range of 0.2 to 2.

0.

15. The open-type earphone according to claim 1, characterized in that the housing includes a main body and a baffle, the main body defines a first cavity for housing the acoustic driver, the baffle is connected to the side of the main body away from the user's face, and the baffle extends toward the ear canal relative to the main body.

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