Open-back headphones

Abstract

The present invention provides open-type headphones having an acoustic module configured to be located within the concha of the user's outer ear. [Solution] The open-type headphones 10 include an acoustic module 12 located at least partially within the concha 51 of the user's outer ear 50. The acoustic module 12 includes a housing that accommodates an acoustic transducer. The housing has a first sound-emitting opening 16 that radiates sound generated by the acoustic transducer. The acoustic module 12 defines a central longitudinal axis, and the first sound-emitting opening 16 is offset from the central axis.

Description

Technical Field

[0001] The present disclosure relates to open headphones that are worn on the ear.

Background Art

[0002] Open headphones typically radiate sound near the ear canal rather than inside the ear canal.

Summary of the Invention

Means for Solving the Problems

[0003] Aspects and examples are directed to open headphones having an acoustic module configured to be positioned in the concha of a user's outer ear. In some embodiments, the acoustic module is configured to be positioned within the conchal cavity. The acoustic module includes a housing that accommodates an acoustic transducer. The housing has a sound-emitting opening configured to radiate sound generated by the acoustic transducer. The sound-emitting opening is offset from the central longitudinal axis of the acoustic module such that the opening is in very close proximity to the external auditory meatus but not located within the external auditory meatus. Positioning the opening in this manner increases acoustic output gain and thus provides a better user experience.

[0004] All examples and features mentioned below can be combined in any technically feasible manner.

[0005] In one aspect, the open headphone includes an acoustic module configured to be positioned at least partially within the concha of a user's outer ear. The acoustic module includes a housing that accommodates an acoustic transducer. The housing has a first sound-emitting opening configured to radiate sound generated by the acoustic transducer. The acoustic module defines a central longitudinal axis, and the first sound-emitting opening is offset from the central axis.

[0006] Some embodiments include one of the above and / or below features, or any combination thereof. In one embodiment, the first sound-emitting opening is offset mainly or entirely from the central longitudinal axis such that the first sound-emitting opening does not overlap with the central longitudinal axis. In one embodiment, the central longitudinal axis bisects the acoustic module housing. In some embodiments, the open-type headphones also include a body coupled to the acoustic module and comprising a first portion configured to pass over the outside of at least one of (i) the antihelix and helix, and (ii) the earlobe of the outer ear, and a second portion configured to be located behind the outer ear. In one embodiment, the central longitudinal axis bisects the acoustic module housing and the first portion of the body. In one embodiment, the acoustic module housing is configured to be spaced away from and close to the user's ear canal opening and defines a front surface that curves with respect to the central longitudinal axis, and the first sound-emitting opening is located within the front surface of the housing.

[0007] Some embodiments include one of the features described above and / or below, or any combination thereof. In some embodiments, the open-type headphones further include a second sound-emitting opening within the acoustic module housing. In one embodiment, the acoustic module housing defines first and second internal acoustic cavities on either side of the acoustic transducer. In one embodiment, the first sound-emitting opening is a sound outlet for the first internal acoustic cavity, and the second sound-emitting opening is a sound outlet for the second internal acoustic cavity. In one embodiment, the acoustic energy from the first sound-emitting opening combines with the acoustic energy from the second sound-emitting opening to provide an acoustic dipole.

[0008] Some embodiments include one of the above and / or below features, or any combination thereof. In some embodiments, the second sound-emitting opening is located opposite the first sound-emitting opening on the central longitudinal axis. In one embodiment, the acoustic module housing defines a front and a side located behind the front, with the first sound-emitting opening located within the front of the acoustic module housing and the second sound-emitting opening located within the side of the acoustic module housing. In one embodiment, the acoustic module housing is configured to be at least partially located within the concha of the outer ear. In one embodiment, the first sound-emitting opening is configured to be substantially closer to the opening of the external auditory canal than the second sound-emitting opening.

[0009] Some embodiments include one of the features described above and / or below, or any combination thereof. In some embodiments, the open-type headphones further include a first microphone opening. In one embodiment, the first microphone opening lies on the same side of the central longitudinal axis as the first sound emission opening. In one embodiment, the open-type headphones further include a second microphone opening, and the bisectors of the first and second microphone openings are configured to point towards the expected position of the mouth of the person wearing the open-type headphones.

[0010] In another embodiment, open-back headphones include an acoustic module configured to be at least partially located within the concha of the user's outer ear. The acoustic module comprises a housing configured to house an acoustic transducer and a first sound-emitting opening within the housing, and to radiate sound produced by the acoustic transducer. The acoustic module defines a central longitudinal axis that bisects the acoustic module housing. The first sound-emitting opening is offset completely or almost completely from the central longitudinal axis such that the first sound-emitting opening does not overlap with the central longitudinal axis, or overlaps with it only slightly.

[0011] Some embodiments include one of the features described above and / or below, or any combination thereof. In some embodiments, the open-type headphones further include a second sound-emitting opening within the acoustic module housing, the acoustic module housing defines first and second internal acoustic cavities on either side of the acoustic transducer, the first sound-emitting opening being a sound outlet for the first internal acoustic cavity, and the second sound-emitting opening being a sound outlet for the second internal acoustic cavity, the second sound-emitting opening being opposite to the first sound-emitting opening with respect to the central longitudinal axis, and the acoustic energy from the first sound-emitting opening combined with the acoustic energy from the second sound-emitting opening to provide an acoustic dipole. In one embodiment, the acoustic module housing defines a front and a side located behind the front, the first sound-emitting opening being within the front of the acoustic module housing, and the second sound-emitting opening being within the side of the acoustic module housing.

[0012] Some embodiments include one of the features described above and / or below, or any combination thereof. In some embodiments, the acoustic module housing is configured to be at least partially located within the concha of the outer ear, and the first sound-emitting opening is configured to be closer to the ear canal opening than the second sound-emitting opening. In one embodiment, the open-type headphones further include a microphone opening that lies on the same side of the central longitudinal axis as the first sound-emitting opening.

[0013] Various aspects of at least one embodiment are discussed below with reference to the accompanying drawings, which are not intended to be drawn to scale. These drawings are included to illustrate and further understand the various aspects and examples, and are incorporated into and form part of this specification, but are not intended to define limitations of the invention. In the drawings, identical or nearly identical components illustrated in the various drawings may be represented by similar letters or numbers. For clarity, not all components may be labeled in all drawings. [Brief explanation of the drawing]

[0014] [Figure 1A] This is a lower perspective view of an open-back headphone configured for the right ear. [Figure 1B] This is a top perspective view of these open-type headphones. [Figure 1C] This is a front view of these open-type headphones. [Figure 2] This is an exemplary polar coordinate plot of the output of a dipole transducer. [Figure 3A] Let's illustrate with the open-type headphones shown in Figures 1A and 1C, which are positioned above the ears. [Figure 3B] Let's illustrate with the open-type headphones shown in Figures 1A and 1C, which are positioned above the ears. [Figure 3C] Let's illustrate with the open-type headphones shown in Figures 1A and 1C, which are positioned above the ears. [Figure 4] Figures 1A to 1C and 3A to 3C are cross-sectional views of open-type headphones. [Figure 5] This is a plot of sound pressure in the ear and two microphones for several exemplary open-back headphone configurations. [Modes for carrying out the invention]

[0015] Open-back headphones, worn on the ears, must provide high-quality sound, be stable on the ears, comfortable for extended wear, inconspicuous, and stylish. These objectives have been considered mutually exclusive in several respects, making them difficult to achieve. For example, stability typically leads to a tight fit on the outer ear, which can be uncomfortable for prolonged wear and may even be unstylish. Furthermore, for high-quality sound, acoustics must be delivered near the ear canal, not inside it, meaning the headphone structure must be worn over the ear, making it clearly visible to others. Also, to achieve the best sound quality without blocking the ear canal, sound should be transmitted near the opening of the ear canal, but not inside it.

[0016] Examples of open-back headphones considered herein are not limited to their application to the configuration details and component arrangements described below or illustrated in the accompanying drawings. Headphones can be implemented in other embodiments and can be practiced or executed in various ways. Specific embodiments are provided herein for illustrative purposes only and are not intended to be limiting. Specifically, functions, components, elements, and features considered in relation to any one or more embodiments are not intended to be excluded from similar roles in any other embodiments.

[0017] The examples disclosed herein can be combined with other examples in any manner consistent with at least one of the principles disclosed herein, and further, references to “an example,” “some examples,” “an alternate example,” “various examples,” and “one example” are not necessarily exclusive to one another, and are intended to indicate that a particular feature, structure, or characteristic described may be included in at least one example. The appearance of such terms herein does not necessarily refer to the same example.

[0018] Furthermore, the expressions and terms used herein are for illustrative purposes only and should not be considered limiting. Any singular reference to an example, component, element, operation, or function of headphones herein may also encompass embodiments including multiple examples, components, elements, operation, or function herein, and any plural reference to an example, component, element, operation, or function herein may also encompass embodiments including only singular examples. Accordingly, singular or plural references are not intended to limit the headphones, components, operations, or elements of the disclosure herein. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein means that they encompass the items listed below and their equivalents, as well as other items. References to “or” should be construed as comprehensive, so as to whether any term described using “or” may refer to one, multiple, or all of the terms described.

[0019] In some embodiments of this specification, open-type headphones include an acoustic module configured to be located within the concha of the user's outer ear, for example, within the concha cavity of the ear. The acoustic module comprises a housing that accommodates an acoustic transducer. A sound-emitting opening within the housing radiates sound produced by the acoustic transducer. The acoustic module defines a central longitudinal axis, and the sound-emitting opening is offset from the central axis. Generally, the opening is offset from the axis on the side of the housing closest to the opening of the ear canal.

[0020] In some embodiments, the sound-emitting opening may be completely or substantially completely offset from the central longitudinal axis so as not to overlap with the central longitudinal axis. In one embodiment, the central longitudinal axis bisects the acoustic module housing. In some embodiments, the open-back headphone also includes a body coupled to the acoustic module, the body comprising a first portion configured to pass over an outer side of at least one of (i) the antihelix and helix, and (ii) the earlobe of the outer ear, and a second portion configured to be positioned behind the outer ear. In one embodiment, the central longitudinal axis bisects the acoustic module housing and the first portion of the body. In one embodiment, the acoustic module housing is configured to be spaced in close proximity to a user's external auditory canal opening, and defines a front surface curved relative to the central longitudinal axis. In some embodiments, the sound-emitting opening is located within the front surface of the housing.

[0021] In some embodiments, the open-back headphone also has a second sound-emitting opening in the acoustic module housing. In one embodiment, the acoustic module housing defines first and second internal acoustic cavities on opposite sides of the acoustic transducer. In one embodiment, the first sound-emitting opening is a sound outlet for the first internal acoustic cavity, and the second sound-emitting opening is a sound outlet for the second internal acoustic cavity. In one embodiment, acoustic energy from the first sound-emitting opening combines with acoustic energy from the second sound-emitting opening to provide an acoustic dipole. This reduces sound leakage that may be audible to other persons near the headphone user.

[0022] In some embodiments, the second sound-emitting opening is located on an opposite side of the central longitudinal axis from the first sound-emitting opening. In one embodiment, the acoustic module housing defines a front surface and a side surface rearward of the front surface. In one embodiment, the first sound-emitting opening is located in the front surface of the acoustic module housing, and the second sound-emitting opening is located in the side surface of the acoustic module housing. In one embodiment, the first sound-emitting opening is configured to be substantially closer to the external auditory canal opening than the second sound-emitting opening.

[0023] In some embodiments, the open-back headphones further comprise one or more microphone openings each allowing sound to enter the housing and be sensed by a microphone. In one embodiment, one microphone opening is located on the same side of the central longitudinal axis as the sound-emitting opening. In one embodiment, a bisector of the first and second microphone openings is configured to face towards an expected position of the mouth of a person wearing the open-back headphones. This configuration facilitates the arrangement of microphones to more selectively detect a user's voice in the presence of environmental noise.

[0024] The open-back headphones disclosed herein can meet all of these objectives. An acoustic transducer or driver is an acoustic module configured to be positioned close to the external auditory canal within the concha cavity of the outer ear. The acoustic module has a sound-emitting opening on a side configured to be closest to the external auditory canal, which leads to higher quality sound and greater acoustic output. The acoustic module is shaped to fit within the lower concave portion of the concha cavity. A body section carrying the acoustic module is shaped to pass over the outside of the antihelix / helix / lobule of the ear and terminates at a distal portion positioned behind the outer ear. The center of gravity of the open-back headphones is between the acoustic module and the distal portion, and thus is within or in the immediate vicinity of the antihelix, helix, or lobule, which leads to higher stability on the ear without the need for clamping to the ear. Therefore, the open-back headphones are comfortable for prolonged wearing.

[0025] Embodiments of the headphones described herein are not limited to application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The headphones can be embodied in other embodiments and can be practiced or carried out in various ways. Specific embodiments are provided herein for illustrative purposes only, and are not intended to be limiting. Specifically, the functions, components, elements, and features discussed in connection with any one or more embodiments are not intended to be excluded from similar roles in any other embodiments.

[0026] The examples disclosed herein can be combined with other examples in any manner consistent with at least one of the principles disclosed herein, and further, references to “an example,” “some examples,” “an alternate example,” “various examples,” and “one example” are not necessarily exclusive to one another, and are intended to indicate that a particular feature, structure, or characteristic described may be included in at least one example. The appearance of such terms herein does not necessarily refer to the same example.

[0027] Furthermore, the expressions and terms used herein are for illustrative purposes only and should not be considered limiting. Any singular reference to an embodiment, component, element, action, or function of a device herein may also encompass a plural embodiment, and any plural reference to any example, component, element, action, or function herein may also encompass an embodiment that includes only the singular form. Accordingly, references to singular or plural forms are not intended to limit the devices, components, actions, or elements of the disclosure. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein means that they encompass the items listed below and their equivalents, as well as other items. References to “or” may be construed as comprehensive, so as to whether any term described using “or” may refer to one, plural, or all of the terms described.

[0028] This disclosure features open-type headphones comprising: an acoustic module configured to be at least partially located within the concha of the user's outer ear and comprising an acoustic transducer and a first sound-emitting opening configured to emit sound produced by the acoustic transducer; and a body coupled to the acoustic module and comprising a first portion configured to pass over the outside of the outer ear and a second portion configured to be located behind the outer ear. The first sound-emitting opening is preferably located within the concha cavity and configured to be adjacent to the opening of the user's ear canal, away from and close to the opening of the ear canal. In some embodiments, the acoustic module is configured to be located within the concha cavity. In certain embodiments, the acoustic module has a lower portion that is outwardly convex and configured to sit on the lower concave surface of the concha cavity adjacent to the antitragus and lobe of the user's ear.

[0029] Open-back headphones are configured such that the body passes over at least one of the antihelix, helix, and lobe of the ear when the acoustic module is positioned within the concha of the ear. In one embodiment, the body is substantially "L" shaped, and the acoustic module and body as a whole (i.e., the entire open-back headphone) is substantially "C" shaped. In some embodiments, the acoustic module includes a second sound-emitting opening configured to be further from the ear canal opening than a first sound-emitting opening. The sound-emitting openings can be arranged to achieve a dipole-shaped pattern that can result in acoustic cancellation that reduces sound leakage that may be heard by others. In one embodiment, an acoustic transducer generates sound pressure within the front and rear acoustic cavities of the acoustic module, with the first sound-emitting opening fluid-coupled to the front acoustic cavity and the second sound-emitting opening fluid-coupled to the rear acoustic cavity.

[0030] In some embodiments, a second part of the body includes a battery housing configured to house a battery power source for open-back headphones. A printed circuit board may be present in the first part of the body and electrically coupled to the battery, and a flexible circuit element may be present that electrically couples the printed circuit board to an acoustic transducer. In some embodiments, the open-back headphones also include a pair of microphones positioned directly below the opening, allowing external sounds to reach the microphones. These microphones may be positioned on either side of the first part of the body, such that one microphone is configured to be further from the user's mouth than the second microphone. The axes passing through the microphones are generally aligned with the user's mouth. The microphones may be arranged by beam steering or the like to improve the capture of the user's voice in the presence of noise or other external sounds.

[0031] Figures 1A–1C, 3A–3C, and 4 illustrate an exemplary open-back headphone 10. The open-back headphone 10 includes an acoustic module 12 that is sized, molded, and positioned within an open-back headphone body 13, such that the acoustic module 12 is configured to be located within the concha of the user's outer ear. Generally, the human outer ear (also known as the auricle or ala) includes the concha, located below (or behind) the tragus and directly adjacent to the entrance to the external auditory canal. The concha is divided by the crus of the helix into a lower portion called the concha cavus and an upper portion called the concha scaphelix. The concha cavus is a roughly bowl-shaped feature directly adjacent to the external auditory canal. The concha cavus typically includes a recess bounded by the antitragus, which is the lower part of the antihelix, and / or by the lobe. The lobe (i.e., the earlobe), located at the lower end of the helix, is typically directly below the antitragus.

[0032] The body 13 of the open-back headphones 10 includes a first portion 20 configured to be coupled to an acoustic module 12 and to pass over the outside of the ear (e.g., at least one of the antihelix and helix of the outer ear, and the earlobe), and a second portion 14 configured to be located behind the outer ear. The body 13 is generally molded in an "L" shape from the side (e.g., as shown in Figures 3A and 4), with portion 20 extending approximately perpendicular to the acoustic module 12, and a connecting portion 17 extending approximately perpendicular to portion 20 and connecting to the distal portion 14. In one embodiment, portion 14 may be substantially cylindrical, such as being configured to hold a substantially cylindrical battery power source (e.g., a rechargeable battery). As shown in Figures 1A, 1B, 3A, and 4, the open-back headphones 10 as a whole are substantially "C" shaped. In one embodiment, the acoustic module 12 and the body 13 are part of a integrally molded plastic housing configured and arranged to house at least a transducer and any electronic equipment necessary for the operation of the headphones. The gap 22 between part 14 and part 20 accommodates the outer ear, as further described elsewhere in this specification.

[0033] The acoustic module 12 includes a first sound-emitting opening or port 16 located in the portion of the housing configured to be closest to the user's external auditory canal opening. The front surface 12a of the acoustic module 12 is generally oriented towards the posterior part of the concha and not directly towards the external auditory canal opening; therefore, the front surface 12a is generally not the portion of the acoustic module 12 closest to the external auditory canal opening. Also, the front surface of the housing is curved with respect to the axis 11, as shown in Figure 1C. Positioning the opening 16 off-center from the front surface 12a (in some embodiments, mostly or entirely below the central longitudinal axis 11 of the housing) places the opening 16 as close as possible to the external auditory canal opening. In one embodiment, the opening 16 is about 2 mm closer to the external auditory canal opening than if the opening 16 were centered on the axis 11. This results in an acoustic output gain of up to about 2 dB. In some embodiments, the opening 16 is completely offset from the axis 11; in other words, the opening 16 does not intersect the axis 11. In other embodiments (as shown in Figure 1C), the opening 16 slightly overlaps with the axis 11, but the majority of the opening 16 is on one side of the axis 11. In some embodiments, headphones for the right and left ears are essentially the same, except that the opening 16 is entirely or largely bisected below the axis 11 and therefore on both sides of the axis 11 for the opposing ears.

[0034] In some embodiments, the headphones 10 include a second sound-emitting opening 24 configured to be further from the ear canal opening than a first sound-emitting opening 16. The two sound-emitting openings can be arranged to achieve a dipole-like pattern that can result in acoustic cancellation that reduces sound leakage that may be heard by others. In one embodiment, an acoustic transducer generates sound pressure within the front and rear acoustic cavity portions of the acoustic cavity of the acoustic module, with the first sound-emitting opening 16 being fluid-coupled to the front acoustic cavity and the second sound-emitting opening 24 being fluid-coupled to the rear acoustic cavity. The sound-emitting openings can be covered with a resistive or environmentally friendly element such as cloth or fabric. In some embodiments, the volumes of the front and rear acoustic cavities, along with the areas of the openings 16 and 24, are selected to achieve similar front and rear cavity resonances. This helps to maximize far-field cancellation and thus minimize sound leakage. In some embodiments, the second opening or port 24 is located on the opposite side of the axis 11 from the opening 16. This allows the front and rear openings to be spaced apart, as long as it is practical in the headphone design, which supports dipole-like performance and maximizes the acoustic output in the near field of the front opening over a range of appropriate positions in the device. The rear vent 24 can also be placed further away from the microphone, thereby reducing acoustic echo picked up by the microphone from the loudspeaker.

[0035] In some embodiments, the open-type headphones 10 carry one or more external microphones. The external microphones can be used to sense the user's voice and / or ambient noise, and / or as feedforward microphones for an active noise cancellation system. In this example, the external microphones are located directly below the microphone openings 18 and 26, and these microphone openings are located on both sides of the body portion 20 such that they are generally positioned along an axis that intersects or passes through the expected position of the user's mouth. Thus, the microphones can be beamformed if desired. Also, positioning the microphones between the front and rear ports (as is generally the case with microphone 26) places the microphones in a null region of the generally dipole cardioid emission pattern, which reduces the amount of sound being sensed from either the front or rear opening.

[0036] At low frequencies, acoustic drivers often exhibit a dipole radiation pattern, where sound is radiated in opposite directions (0 and 180 degrees), with a 180-degree phase shift, resulting in substantially lower sound pressure along orthogonal axes (90 and 270 degrees), defining a null. Figure 2 is a polar coordinate plot of the output of a single driver in a housing with both front and rear sound-emitting openings, with and without acoustically resistive mesh material above the rear port opening. The plots in Figure 2 were acquired at 200 Hz and show typical dipole radiation with and without mesh (curve 31) and without mesh. This illustrates one embodiment of a single-driver implementation in this open-type headphone, where, at low frequencies, the sound is canceled out in the far field. At high frequencies, most of the acoustic energy is directed towards the wearer's ears rather than in other directions.

[0037] Figures 3A–3C illustrate how the open-back headphones in Figures 1A–1C fit with the outer ear. As shown in Figures 3A and 3B, the acoustic module 12 sits within the concha 51 of the outer ear 50 (the right ear is illustrated). A first sound-emitting opening 16 radiates sound produced by an acoustic transducer within the acoustic module 12. The sound-emitting opening 16 is spaced apart from and close to the user's ear canal opening 63. In this example, the acoustic module 12 has a lower portion 19 that is outwardly convex and is configured to sit within the lower concave surface 52 of the concha 51. Thus, the weight of the open-back headphones is suspended from the concha, which holds the headphones on the ear without requiring them to be clamped to the ear. Light clamping of the open-back headphones to the ear can be easily achieved using built-in compliance. In some embodiments, at least part 17 is made at least partially from an elastomer or includes a hinge element so that it can bend relative to part 20, thereby changing the position of part 14 and altering the thickness of the gap 22 between parts 20 and 14 in Figure 1A, which surrounds the ear part 54. A suitable compliant elastomer may have a hardness of 80 durometers Shore A. Details of the structure and bending of part or arm 17 are further disclosed in two U.S. Patent Applications identified by Agent Reference Numbers 22706-00375 / OG-21-327-US and 22706-00374 / OG-21-322-US, the entirety of which is incorporated herein by reference for any purpose.

[0038] Open-back headphones are configured such that the body passes over at least one of the antihelix, helix, and earlobe of the ear when the acoustic module is positioned within the concha of the ear, and any one or more of these parts of the ear 50 are generally represented as 54 in Figure 3A. The user can pivot the body to a comfortable or other desired position on the outer ear. A second body portion 14 is located behind the outer ear. In other words, as shown in Figure 3A, it is located between the outer ear 50 and an adjacent portion of the head 55. Portion 17 connects to portions 20 and 14 and is configured to pass over the edge 59 of the outer ear 50. As shown in Figure 3B, portion 20 is seated at an angle to the vertical axis 39 such that portion 17 is generally below the acoustic module 12. As shown in Figure 3B, the opening 16 is located on the underside of the front surface 12a of the acoustic module 12; therefore, the opening 16 is effectively in the portion of the acoustic module 12 closest to the ear canal opening 63. Further aspects of how the open-type headphones 10 interact with the outer ear 50 are described more fully in the U.S. patent incorporated herein by reference.

[0039] Figure 3C illustrates that the microphone apertures 18 and 26 are roughly aligned along an axis 35 intersecting the aperture 37. As will be described in more detail elsewhere in this specification, this alignment helps enable the microphone to beamform, which can increase the signal-to-noise ratio of the speech.

[0040] Figure 4 is a schematic partial cross-sectional view of an open-type headphone 10 illustrating a battery 80 supported inside the main body portion 14. The acoustic module 12 supports an acoustic transducer 82 that generates sound pressure within an acoustic cavity 90. The sound emission opening 16 is located in the end of the acoustic module 12 closest to the ear canal opening 63. Sound is radiated through the opening 16 as indicated by the arrow 92. In some embodiments, the headphone set includes one left headphone and one right headphone, having configurations specific to a given ear (e.g., the position of the front port opening). A printed circuit board (PCB) 84 is located inside the main body portion 20 and is electrically coupled to the battery 80. A flexible circuit element 86 carries at least power and audio signals to the transducer 82 through the PCB 84. User interface elements can optionally be incorporated within the main body portion.

[0041] Further details of the open-back headphones, including but not limited to their structure, operation, and acoustic performance, are disclosed in U.S. Patent No. 11,140,469, the entire disclosure of which is incorporated herein by reference for all purposes. The embodiments of the open-back headphones disclosed herein are not further described herein.

[0042] Figure 5 illustrates exemplary sound pressure data 110 (sound pressure level (SPL)) from three different configurations of open-back headphones at 200 Hz. The first configuration (both rear vents with a centrally located nozzle) is a configuration as disclosed in the U.S. Patents incorporated herein by reference, in which the front opening or nozzle is centrally located on the axis 11 (Figure 1C) and there are two rear or rear vents. The second configuration (both rear vents with an offset nozzle) is the same as the first configuration except that the nozzle is offset from the axis 11, as shown in Figure 1C. The third configuration (only one upper rear vent with an offset nozzle) has the same nozzle position as the second configuration but has only one rear vent, which is the "upper" vent, meaning it is on the upper side of the acoustic module when the open-back headphones are worn on the ears (e.g., rear vent 24 in Figure 1B).

[0043] The ear dataset (dataset 112) establishes that moving the nozzle 16 to an offset position increases the sound pressure in the ear. In addition, there are upper or upward vents and lower or downward vents, along with both rear vents. The upper vent 24 in Figure 1B has lower pressure than the lower vent at position 25 in Figure 1A. Because the upper vent has lower pressure, it cancels less sound (from the nozzle) in the ear, and therefore yields better performance using a single (upper) rear vent compared to two rear vents.

[0044] Data set at the location of "microphone 1" (position 26 in Figure 1A) establishes that removing the second rear vent 25 and thus having a single (upper) rear vent leads to improved performance (i.e., reduced sound detected by microphone 1). This improvement is likely due to moving the sound source closest to microphone 1 (the rear vent at position 25) further away from the microphone. Here, the closest sound source is the nozzle 16. Consequently, there is less acoustic extraction from the speaker to this microphone, enabling better performance during double-talk.

[0045] Datasets at the location of "microphone 2" (located at position 18 in Figure 1B) establish that a single rear vent 24 increases the sound perceived by microphone 2. This is likely due to the elongation of vent 24 compared to a smaller rear vent at this location in the version with two rear vents. The vent is elongated as a means of maintaining approximately the same total rear vent volume as the version with two rear vents, but has only a single rear vent. The elongation of vent 24 places a portion of vent 24 closer to microphone 2.

[0046] While several embodiments relating to at least one example have been described, it will be understood that various changes, modifications, and improvements can be readily conceived by those skilled in the art. Such changes, modifications, and improvements are intended to be part of the present disclosure and within the scope of the invention. Accordingly, the foregoing description and drawings are merely illustrative, and the scope of the invention should be determined from the appropriate configuration of the appended claims and their equivalents. [Explanation of Symbols]

[0047] 10 Open-back headphones 11 axes 12 acoustic modules 12a front 13 Main unit 14 Part 2 16 First sound emission opening 17 Connection part 18 Microphone opening 19 Lower part 20 Part 1 22 Gap 24. Second sound-releasing opening (vent) 26 Microphones 31 curve 33 curve 35 axes 37 mouths 39 Vertical (vertical) axis 50 outer ear 51 Concha cavity 52 Lower concave surface 54 Ear part 55 Head 59 Edge 63 External auditory canal opening 80 batteries 82 Acoustic Transducers 86 Flexible Circuit Elements 90 acoustic cavity 92 Arrow 110 Sound pressure data 112 datasets

Claims

1. These are open-back headphones, An acoustic module configured to be at least partially located within the concha of the outer ear of a user, wherein the acoustic module comprises a housing that houses an acoustic transducer and a first sound-emitting opening within the housing, and is configured to emit sound generated by the acoustic transducer, The acoustic module defines a central longitudinal axis, and the first sound-emitting opening is offset from the central longitudinal axis, in an open-type headphone.

2. The open-type headphones according to claim 1, wherein the first sound-emitting opening is offset almost completely from the central longitudinal axis such that the first sound-emitting opening barely overlaps with the central longitudinal axis.

3. The open-type headphones according to claim 1, wherein the central longitudinal axis bisects the housing of the acoustic module.

4. The open-type headphones according to claim 1, further comprising a body that is coupled to the acoustic module and has a first portion configured to pass over the outer part of at least one of the antihelix and helix and the lobe of the outer ear, and a second portion configured to be located behind the outer ear.

5. The open-type headphones according to claim 4, wherein the central longitudinal axis bisects the housing of the acoustic module and the first portion of the main body.

6. The open-type headphones according to claim 1, wherein the housing of the acoustic module is configured to be located away from and close to the opening of the user's ear canal, and defines a front surface that curves with respect to the central longitudinal axis, and the first sound-emitting opening is located within the front surface of the housing.

7. The open-type headphones according to claim 1, further comprising a second sound-emitting opening within the housing of the acoustic module.

8. The open-type headphones according to claim 7, wherein the housing of the acoustic module defines first and second internal acoustic cavities on both sides of the acoustic transducer.

9. The open-type headphones according to claim 8, wherein the first sound-emitting opening is a sound outlet for the first internal acoustic cavity, and the second sound-emitting opening is a sound outlet for the second internal acoustic cavity.

10. The open-type headphones according to claim 9, wherein the acoustic energy from the first sound-emitting opening combines with the acoustic energy from the second sound-emitting opening to provide an acoustic dipole.

11. The open-type headphones according to claim 9, wherein the second sound-emitting opening is located on the opposite side of the central longitudinal axis from the first sound-emitting opening.

12. The open-type headphones according to claim 11, wherein the housing of the acoustic module defines a front surface and a side surface located behind the front surface, the first sound-emitting opening is located within the front surface of the housing of the acoustic module, and the second sound-emitting opening is located within the side surface of the housing of the acoustic module.

13. The open-type headphones according to claim 12, wherein the housing of the acoustic module is configured to be at least partially located within the concha of the outer ear.

14. The open-type headphones according to claim 13, wherein the first sound-emitting opening is configured to be substantially closer to the user's ear canal opening than the second sound-emitting opening.

15. The open-type headphones according to claim 11, further comprising a first microphone opening.

16. The open-type headphones according to claim 15, wherein the first microphone opening is located on the same side surface as the first sound emission opening along the central longitudinal axis.

17. The open-type headphones according to claim 15, further comprising a second microphone opening, wherein the bisectors of the first and second microphone openings are directed toward the expected position of the mouth of a person wearing the open-type headphones.

18. These are open-back headphones, An acoustic module configured to be at least partially located within the concha of the outer ear of a user, wherein the acoustic module comprises a housing that houses an acoustic transducer and a first sound-emitting opening within the housing, and is configured to emit sound generated by the acoustic transducer, The aforementioned acoustic module defines a central longitudinal axis that bisects the housing of the acoustic module, An open-type headphone in which the first sound-emitting opening is offset almost completely from the central longitudinal axis such that the first sound-emitting opening barely overlaps with the central longitudinal axis.

19. Open-type headphones according to claim 18, further comprising a second sound-emitting opening within the housing of the acoustic module, wherein the housing of the acoustic module defines first and second internal acoustic cavities on both sides of the acoustic transducer, the first sound-emitting opening being a sound outlet for the first internal acoustic cavity, and the second sound-emitting opening being a sound outlet for the second internal acoustic cavity, the second sound-emitting opening being on the opposite side of the central longitudinal axis from the first sound-emitting opening, and the acoustic energy from the first sound-emitting opening combined with the acoustic energy from the second sound-emitting opening to provide an acoustic dipole.

20. The open-type headphones according to claim 19, wherein the housing of the acoustic module defines a front surface and a side surface located behind the front surface, the first sound-emitting opening is located within the front surface of the housing of the acoustic module, and the second sound-emitting opening is located within the side surface of the housing of the acoustic module.

21. The open-type headphones according to claim 20, wherein the housing of the acoustic module is configured to be at least partially located within the concha of the outer ear, and the first sound-emitting opening is configured to be closer to the user's ear canal opening than the second sound-emitting opening.

22. The open-type headphones according to claim 21, further comprising a microphone opening located on the same side surface as the first sound-emitting opening and the central longitudinal axis.

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