Patent Publication Number: US-11044542-B2

Title: Composite earcushion

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 120 as a continuation-in-part of U.S. patent application Ser. No. 16/250,273, titled COMPOSITE EARCUSHION, filed Jan. 17, 2019, now U.S. Pat. No. 10,659,816, which is a continuation of U.S. patent application Ser. No. 15/716,796, titled COMPOSITE EARCUSHION, filed Sep. 27, 2017, now U.S. Pat. No. 10,187,716, both of which are incorporated by reference herein in their entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     Aspects and implementations of the present disclosure are directed generally to a composite earcushion and to headphones including same. 
     BACKGROUND 
     Wireless and mobile electronic devices are increasingly popular. In some instances, the sound generated by the wireless and mobile electronic devices is transmitted through wires to one or more speakers that are positioned adjacent to the user&#39;s ears. In some instances, the generated sound can be transmitted to speakers via wireless transmission devices. One example of a speaker system positioned adjacent to the user&#39;s ears is a set of headphones. 
     In addition to speakers, headphones can include materials for softening the contact of the headphones against the user&#39;s ear (a supra-aural design) or against portions of the user&#39;s head adjacent to the user&#39;s ears (a circum-aural design). The materials are intended to provide comfort to the user as the headphones are used and may reduce the amount of external noise reaching the user&#39;s ear and/or may absorb noise such as audio rendered by an audio driver of the headphones that is reflected from a portion of the user&#39;s ear or head, or any reverberant sound wave within the earcushion plenum. These materials may be formed into what is referred to herein as headphone cushions or earcushions. 
     SUMMARY 
     In accordance with an aspect of the present disclosure, there is provided a headphone cushion that includes a body formed of a partially reticulated polymeric foam, the body including a front surface configured to engage or surround an ear or head of a user, side surfaces, and a rear surface. The headphone cushion further includes a layer of high-density polymer material extending over at least a portion of the body. 
     The headphone cushion may further include a snap ring at least partially embedded in the body, the snap ring including a periphery configured to engage one or more retention elements of an earcup of a headphone. The snap ring may include a curved portion having a concave surface facing away from the ear of the user when the front surface of the headphone cushion is held adjacent the ear or head of the user. The curved portion of the snap ring may form an acoustic wall that improves passive transmission loss performance of the headphone cushion for acoustic frequencies in a range of about 0.2 kHz to about 6.5 kHz. The body may include a stepped portion extending from the rear surface of the body and onto one of an internal periphery and an external periphery of a rear surface of the snap ring. 
     The headphone cushion may further include a non-porous film on the front and side surfaces of the body, the non-porous film being distinct from the layer of high-density polymer material. 
     The high-density polymer material may include at least one of silicone and molybdenum. 
     The layer of high-density polymer material may extend over at least a portion of the front surface. The layer of high-density polymer material may extend at least substantially entirely over the front surface and uniformly coat the front surface. 
     The rear portion of the body may include at least one cavity defined between an inner periphery and an outer periphery of the rear portion of the body. 
     The layer of high-density polymer material may have a thickness of between about 10 μm and about 100 μm. 
     In accordance with another aspect of the present disclosure, there is provided a headset including an earcup having a front opening configured to be adjacent to an ear or head of a user when worn by the user. The headset further includes a headphone cushion secured to the front opening of the earcup. The headphone cushion includes a body formed of a partially reticulated polymeric foam, the body including a front surface configured to engage or surround the ear or head of the user, and a rear surface. The headphone cushion further includes a layer of high-density polymer material extending over at least a portion of the body. 
     The headphone cushion may further include a snap ring at least partially embedded in and integrally formed with the body, the snap ring including a periphery configured to engage one or more retention elements of the earcup. The snap ring may include a curved portion that has a concave surface that faces away from the ear of the user when the front surface of the headphone cushion is held adjacent the ear or head of the user. The one or more retention elements of the earcup may include one or more detents extending inwardly from an inner wall of the earcup. The snap ring may be configured to engage rear surfaces of the one or more detents to secure the headphone cushion to the front opening of the earcup. The one or more retention elements of the earcup may include one or more slots configured to receive one or more respective tabs extending from a rear surface of the snap ring. 
     The headphone cushion may further include a non-porous film integral with the front surface of the body, the non-porous film being distinct from the layer of high-density polymer material. 
     The body of the headphone cushion may include a stepped portion extending from the rear surface of the body, onto an internal periphery of a rear surface of the snap ring, and into an interior portion of the earcup. 
     In accordance with another aspect of the present disclosure, there is provided a method of forming a headphone cushion. The method includes molding a body, the body being formed of a partially reticulated polymeric foam and including a front surface configured to engage or surround an ear or head of a user, side surfaces, and a rear surface. The method further includes applying a layer of high-density polymer material to at least a portion of the body. 
     The body may be molded around a snap ring, the snap ring being at least partially embedded in and integrally formed with the body and including a periphery configured to engage one or more retention elements of an earcup of a headphone. The snap ring may include a curved portion that has a concave surface that faces away from the ear of the user when the front surface of the headphone cushion is held adjacent the ear of the user. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings: 
         FIG. 1  is an elevational view of an example of a headphone; 
         FIG. 2A  illustrates an example of a supra-aural headphone cushion disposed against an ear of a user; 
         FIG. 2B  illustrates an example of a circum-aural headphone cushion disposed against a head of a user; 
         FIG. 3A  is an isometric view of an implementation of a headphone cushion; 
         FIG. 3B  is a plan view from the top of the headphone cushion of  FIG. 3A ; 
         FIG. 3C  is a plan view from the bottom of the headphone cushion of  FIG. 3A ; 
         FIG. 3D  is an elevational view of the headphone cushion of  FIG. 3A ; 
         FIG. 3E  is a cross-sectional view of the headphone cushion of  FIG. 3A  along line  3 E of  FIG. 3B ; 
         FIG. 4A  illustrates cells of foam in the bulk of the body of examples of a headphone cushion; 
         FIG. 4B  illustrates cells of foam in a surface of the body of examples of a headphone cushion; 
         FIG. 5  illustrates an example of an earphone earcup configured to retain the headphone cushion of  FIG. 3A ; 
         FIG. 6A  is an isometric view of another implementation of a headphone cushion; 
         FIG. 6B  is a plan view from the top of the headphone cushion of  FIG. 6A ; 
         FIG. 6C  is a plan view from the bottom of the headphone cushion of  FIG. 6A ; 
         FIG. 6D  is an elevational view of the headphone cushion of  FIG. 6A ; 
         FIG. 6E  is a cross-sectional view of the headphone cushion of  FIG. 6A  along line  6 E of  FIG. 6B ; 
         FIG. 6F  is an example of the headphone cushion of  FIG. 6A  including cavities defined in a rear surface; 
         FIG. 6G  is an example of the headphone cushion of  FIG. 6A  including a hollowed-out portion; 
         FIG. 6H  is another example of the headphone cushion of  FIG. 6A  including a hollowed-out portion; 
         FIG. 7  illustrates an example of an earphone earcup retaining the headphone cushion of  FIG. 6A ; 
         FIG. 8  is a graph depicting passive transmission loss as a function of frequency for an example of a headphone cushion; 
         FIG. 9  is a graph depicting passive transmission loss as a function of frequency for another example of a headphone cushion; 
         FIG. 10A  illustrates an example of a headphone cushion with an L-shaped acoustic wall; 
         FIG. 10B  illustrates another example of a headphone cushion with an L-shaped acoustic wall; 
         FIG. 10C  illustrates an example of a headphone cushion with a Y-shaped acoustic wall; and 
         FIG. 10D  illustrates an example of a headphone cushion with a curved acoustic wall. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects and implementations disclosed herein are not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. Aspects and implementations disclosed herein are capable of being practiced or of being carried out in various ways. 
     Referring to  FIG. 1 , there is shown an example of a headphone  10 . The headphone  10  includes two earphones  12 , connected by a headband. Each earphone  12  includes a cup shaped shell or earcup  14  and an earcushion  16 . The headband exerts a force in an inward direction as represented by arrows  19 . In some implementations, headphone  10  is a supra-aural headphone. When worn by a user, the earcushions  16  rest against the user&#39;s ears  18  and may deform slightly to form a seal against the user&#39;s ears  18 , as illustrated in  FIG. 2A . In other implementations, headphone  10  is a circum-aural headphone and when worn by a user, the earcushions  16  rest against portions of the user&#39;s head  17  surrounding the user&#39;s ears  18  and may deform slightly to form a seal against the portions of the user&#39;s head, as illustrated in  FIG. 2B . The seal of the earcushion  16  against the ears of the user or against the portion of the head of the user about the ears of the user may reduce the total external acoustic energy reaching the ear canals of the user. 
     One implementation of an earcushion  20  is illustrated in isometric view in  FIG. 3A , in a plan view from the top (the user contacting side) in  FIG. 3B , in a plan view from the bottom (the headphone earcup contacting side) in  FIG. 3C , in an elevational view in  FIG. 3D , and in a cross-sectional view in  FIG. 3E . The earcushion  20  may be substantially oval in shape and may be sized to either rest against or surround a user&#39;s ear  18 . 
     The earcushion  20  includes a foam body  22  having an upper surface  21 , side surfaces  23 , and a lower surface  32 . The foam body  22  may include or consist of a bulk, or inner portion, and an outer surface. Both may include or consist of a polyurethane foam and/or another type of compliant material. The material of the bulk of the foam body  22  may be a partially reticulated polymer foam having cell sizes within the bulk of the foam body  22  with diameters of between about 100 μm and about 750 μm, for example, as illustrated in  FIG. 4A . The cell size at the outer surface of the foam body  22  may be smaller than that in the bulk of the foam body  22 , for example, with diameters of between about 25 μm and about 100 μm, as illustrated in  FIG. 4B . When uncovered by another material, the outer surface of the foam body  22  may be at least partially acoustically transparent to allow sound waves to pass through the outer surface and into the bulk of the foam body  22 . The foam body  22  may allow air to flow through at a rate of about 10 cm 3 /cm 3 ·second or less and may have an acoustic dampening peak at between about 1 kHz and about 2.5 kHz. 
     In some implementations, the upper surface  21  and side surfaces  23  of the foam body  22  may be covered by a substantially or wholly non-porous material  28  that reduces the amount of external noise entering into the foam body  22  through the upper surface  21  and side surfaces  23  of the foam body  22  and travelling to the ear of a user wearing a headphone  10  fitted with the earcushion  20 . In some examples, the material  28  may be a high-density polymer material, such as silicone rubber having a density in the range of 0.7 g/cm 3  to 3.8 g/cm 3 . The high-density polymer material may include metallic particles, wherein the metallic particles increase the density of the high-density polymer material  28 . In some examples, the metallic particles may be molybdenum. Alternatively, the particles may be formed of another material, which may not be metallic. The particles may be significantly smaller than the smallest cell of the bulk of the foam body  22 . For example, the particles may have characteristic dimensions, for example, diameters, in the range of less than 1 μm to about 10 μm. 
     In other implementations, the material  28  may be an acrylic paint film. The acrylic paint film may have a thickness in the range of about 1-5 μm, for example. In some examples, the acrylic paint film has a thickness of about 1 μm. The acrylic paint film may be more durable than materials such as polyurethane leather (pleather) used in some previous examples of earcushions and may thus have an extended life and may not shed particulate matter as some pleather materials do. The color of the acrylic paint film may be selected as desired by a manufacturer. The upper surface  21  and side surfaces  23  of the foam body  22  may be substantially smooth and include no pleats, folds, or creases. In other implementations, the upper surface  21  and/or side surfaces  23  of the foam body  22  may be molded to include a surface pattern resembling, for example, natural leather. 
     Moreover, in some implementations, the upper surface  21  and side surfaces  23  of the foam body  22  may be covered in two or more layers. For example, the upper surface  21  and side surfaces  23  of the foam body  22  may be covered in two layers, wherein one of the layers may be an acrylic paint film and the other layer a high-density polymer material. The acrylic paint film layer and high-density polymer material layer may be formed as described above. 
     As shown in  FIG. 3A , the earcushion  20  includes a snap ring  24  at least partially embedded in the foam body  22  proximate the lower surface  32  of the foam body  22 . In an example, the snap ring  24  includes one or more prongs  26  extending downward from the lower surface of the snap ring  24 . Six prongs  26  are illustrated in the snap ring  24  of earcushion  20  although other examples may include fewer or greater numbers of prongs  26 . The lower ends of the prongs  26  opposite from the ends of the prongs  26  connected to the snap ring  24  may include hook-like structures  26 A (see  FIG. 3D ). The prongs  26  and their hook-like structures  26 A are used to retain the prongs  26 , and by extension, the entire earcushion  20  in an earcup  14  of a headphone  10  having complimentary recesses  36 , as illustrated in the example shown in  FIG. 5 . In some examples, the snap ring may be insert molded with the foam body  22  of the earcushion  20 . 
     The snap ring  24  and prongs  26  may be formed of a material with a greater rigidity than that of the material of the body  22  of the earcushion  20 . The snap ring  24  and prongs  26  may include or comprise a substantially rigid polymer, for example, polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), acrylic, or poly(methyl methacrylate). 
     Referring to  FIGS. 10A-10D , in some implementations, the snap ring  24  includes a protrusion or acoustic wall  27 . The protrusion or acoustic wall  27  may be made of one or more of PC, ABS, and/or another material. The snap ring  24  may be a single construction, as molded, that includes the protrusion or acoustic wall  27 . The protrusion or acoustic wall  27  may act as a barrier that reflects some amount of acoustic noise from outside the earcushion  20  that passes through the earcushion  20  to the ear of the user as compared to a similar earcushion  20  without the protrusion or acoustic wall  27 . In some implementations, the protrusion or acoustic wall  27  may also absorb some amount of acoustic noise from outside the earcushion  20 . As a result, the presence of the protrusion or acoustic wall  27  may increase the acoustic energies reflected and/or absorbed by the earcushion  20 , thereby improving the passive transmission loss performance across the earcushion  20 . In some implementations, acoustic energies with an acoustic frequency in a range of about 0.1 kHz to 10 kHz may be reflected and/or absorbed, resulting in a lower amount of acoustic energies reaching the user&#39;s ears  18 . 
     As shown in  FIG. 10D , in some examples, the cross-section of the protrusion or acoustic wall  27  may be curved. In other examples, such as the examples shown in  FIGS. 10A-10C , the cross-section of the protrusion or acoustic wall  27  may be straight, or have an L-shape, T-shape, or Y-shape, though other shapes may be used. 
     The presence of the protrusion or acoustic wall  27  reflects the acoustic energies incident upon it and prevents them from reaching the ear canal, thereby improving the passive transmission loss performance across the earcushion  20 .  FIG. 8  depicts test results for acoustic energy absorption in an example of an earcushion  20  without an acoustic wall  27 , showing passive transmission loss across a range of frequencies.  FIG. 9  depicts test results for acoustic energy absorption in an example of an earcushion  20  having a curved acoustic wall  27  (such as that shown in  FIG. 10D ).  FIG. 9  indicates that, at frequencies above 1 kHz, the resulting passive transmission loss is significantly higher, indicating that more acoustic energies have been absorbed in the example of an earcushion  20  having a curved acoustic wall. 
     Returning to discussion of  FIGS. 3A-3E , in some implementations, a stepped portion  30  may extend from the rear surface  32  of the body  22  of the earcushion  20  and onto an external periphery of a rear surface of the snap ring  24 . The stepped portion  30  may facilitate retention of the snap ring  24  in the body  22  of the earcushion  20 , thereby providing an improved seal. 
     At least a portion of the rear surface  32  of the body  22  of the earcushion  20  inside an inner periphery of the snap ring  24  (see  FIG. 3C ) may be free of the substantially or wholly non-porous material  28 , thus exposing the pores on the rear surface  32  of the body  22  of the earcushion  20 . The rear surface  32  of the body  22  of the earcushion  20  may thus be at least partially acoustically transparent and may allow acoustic energy to pass through the rear surface  32  of the body  22  of the earcushion  20  and into the bulk of the body  22  of the earcushion  20 . The earcushion  20  may thus absorb undesirable acoustic energy present in a volume defined between the earcup  14  of a headphone  10  and the head or ear of a user, for example, sound rendered by an acoustic driver of the headphone and reflected from the ear or head of the user, or any other reverberant acoustic energy present within the earcup plenum. Absorption of such acoustic energy may increase the quality of audio perceived by a user wearing a headphone  10  fitted with the earcushion  20 . 
     As illustrated in  FIG. 3E , an acoustic damper  34  may be embedded within the body  22  of the earcushion  20  (in this example, at or near the cross-sectional center of the body  22  of the earcushion  20 ). The acoustic damper  34  may include or consist of a material having a density greater than a density of the partially reticulated polymeric foam forming the body  22  of the earcushion  20 . The material of the acoustic damper  34  may include, for example, silicone or another polymeric material having a density greater than a density of the partially reticulated polymeric foam forming the body  22  of the earcushion  20 . The acoustic damper  34  may be a ring or a rope having a substantially oval or circular shape. Alternatively, the acoustic damper  34  may be embedded as a high-density powder (e.g., a metal powder) dispersed throughout the body  22  of the earcushion  20  at regular or random intervals. The acoustic damper  34  may increase the effective density of the body  22  of the earcushion  20  to reduce the amount of acoustic noise from outside the earcushion  20  that passes through the earcushion  20  to the ear of the user as compared to a similar earcushion  20  without the acoustic damper  34 . 
     Another implementation of an earcushion  40  is illustrated in isometric view in  FIG. 6A , in a plan view from the top (the user contacting side) in  FIG. 6B , in a plan view from the bottom (the headphone earcup contacting side) in  FIG. 6C , in an elevational view in  FIG. 6D , and in a cross-sectional view in  FIG. 6E . The earcushion  40  may be substantially oval in shape and may be sized to either rest against or surround a user&#39;s ear  18 . 
     The earcushion  40  includes a foam body  42  having an upper surface  41 , side surfaces  43 , and a lower surface  52 . The foam body  42  may include or consist of a bulk, or inner portion, and an outer surface. Each of the bulk and the outer surface may include or consist of a polyurethane foam and/or another type of compliant material. The material of the bulk of the foam body  42  may be a partially reticulated polymer foam having cell sizes within the bulk of the foam body  42  with diameters of between about 100 μm and about 750 μm, for example, as illustrated in  FIG. 4A . The cell size at the outer surface of the foam body  42  may be smaller than that in the bulk of the foam body  42 , for example, with diameters of between about 25 μm and about 100 μm, as illustrated in  FIG. 4B . When uncovered by another material, the outer surface of the foam body  42  may be at least partially acoustically transparent to allow sound waves to pass through the outer surface and into the bulk of the foam body  42 . The foam body  42  may allow air to flow through at a rate of about 10 cm 3 /cm 3 ·second or less and may have an acoustic dampening peak at between about 1 kHz and about 2.5 kHz. 
     In some implementations, the upper surface  41  and side surfaces  43  of the foam body  42  may be covered by a substantially or wholly non-porous material  48  which impedes acoustic pressure waves incident on the foam body  42  through the upper surface  41  and side surfaces of the foam body  42  and prevents to a certain degree these pressure waves travelling to the ear of a user wearing a headphone  10  fitted with the earcushion  40 . In some examples, the material  48  may be a high-density polymer material, such as silicone rubber having a density in the range of 0.7 g/cm 3  to 3.8 g/cm 3 . The high-density polymer material may include metallic particles, wherein the metallic particles increase the density of the high-density polymer material  48 . In some examples, the metallic particles may be molybdenum. Alternatively, the particles may be formed of another material, which may not be metallic. The particles may be significantly smaller than the smallest cell of the bulk of the foam body  42 . For example, the particles may have characteristic dimensions, for example, diameters, in the range of less than 1 μm to about 10 μm. 
     In some implementations, the substantially or wholly non-porous material  48  may be an acrylic paint film. The acrylic paint film may have a thickness in the range of about 1-5 μm, for example. In some examples, the acrylic paint film has a thickness of about 1 μm. The color of the acrylic paint film may be selected as desired by a manufacturer. The acrylic paint film may be more durable than materials such as pleather used in some previous examples of earcushions and may thus have an extended life and may not shed particulate matter as some pleather materials do. The upper surface  41  and side surfaces  43  of the foam body  42  may be substantially smooth and include no pleats, folds, or creases. In other implementations, the upper surface  41  and/or side surfaces  43  of the foam body  42  may be molded to include a surface pattern resembling, for example, natural leather. 
     Moreover, in some implementations, the upper surface  41  and side surfaces  43  of the foam body  42  may be covered in two or more layers. For example, the upper surface  41  and side surfaces  43  of the foam body  42  may be covered in two layers, wherein one of the layers may be an acrylic paint film and the other layer a high-density polymer material. The acrylic paint film layer and high-density polymer material layer may be formed as described above. 
     The earcushion  40  includes a snap ring  44  at least partially embedded in the foam body  42  proximate the lower surface  52  of the foam body  42 . In an example, an outermost periphery of a front surface of the snap ring  44  may be substantially coextensive with an outer periphery of the foam body  42  of the earcushion  40 . Front and rear surfaces of the snap ring  44  may be substantially planar. In other examples, the snap ring  44  may have a T-shaped cross-section for enhanced mechanical strength. The outer periphery of the snap ring  44  is configured to engage with tabs or detents  62  in an inner surface of an earcup  14  of a headphone  10  (see  FIG. 7 ) to retain the earcushion  40  in the earcup  14 . 
     The snap ring  44  may be formed of a material with a greater rigidity than that of the material of the body  42  of the earcushion  40 . The snap ring  44  may include or comprise a substantially rigid polymer, for example, polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), acrylic, or poly(methyl methacrylate). 
     Referring to  FIGS. 10A-10D , in some implementations, the snap ring  44  includes a protrusion or acoustic wall  47 . The protrusion or acoustic wall  47  may be made of one or more of PC, ABS, and/or another material. The snap ring  44  may be a single construction, as molded, that includes the protrusion or acoustic wall  47 . The protrusion or acoustic wall  47  may act as a barrier that reflects some amount of acoustic noise from outside the earcushion  40  that passes through the earcushion  40  to the ear of the user as compared to a similar earcushion  40  without the protrusion or acoustic wall  47 . In some implementations, the protrusion or acoustic wall  47  may also absorb some amount of acoustic noise from outside the earcushion  40 . As a result, the presence of the protrusion or acoustic wall  47  may increase the acoustic energies reflected and/or absorbed by the earcushion  40 , thereby improving the passive transmission loss performance across the earcushion  40 . In some implementations, acoustic energies with an acoustic frequency in a range of about 0.1 kHz to 10 kHz may be reflected and/or absorbed, resulting in a lower amount of acoustic energies reaching the user&#39;s ears  18 . 
     As shown in  FIG. 10D , in some examples, the cross-section of the protrusion or acoustic wall  47  may be curved. In other examples, such as the examples shown in  FIGS. 10A-10C , the cross-section of the protrusion or acoustic wall  47  may be straight, or have an L-shape, T-shape, or Y-shape, though other shapes may be used. 
     Returning to discussion of  FIGS. 6A-6H , a stepped portion  50  may extend from the rear surface  52  of the body  42  of the earcushion  40  and onto an internal periphery of a rear surface of the snap ring  44 . The stepped portion  50  may facilitate connection of the snap ring  44  and the body  42  of the earcushion  40 , thereby providing an improved seal. An outer peripheral portion  46  of the rear surface of the snap ring  44  may extend outwardly from beneath the stepped portion  50  of the body  42  of the earcushion  40 . The outer peripheral portion  46  of the rear surface of the snap ring  44  may include exposed material of the snap ring  44  or may be covered by a thin layer of the material of the body  42  of the earcushion  40 . In some implementations, this thin covering layer may have a thickness in the range of about 5-50 μm, for example about 10 μm. 
     At least a portion of the rear surface  52  of the body  42  of the earcushion  40  inside an inner periphery of the stepped portion  50  (see  FIG. 6C ) may be free of the material  48 , thus exposing the pores on the rear surface  52  of the body  42  of the earcushion  40 . The rear surface  52  of the body  42  of the earcushion  40  may thus be at least partially acoustically transparent and may allow acoustic energy to pass through the rear surface  52  of the body  42  of the earcushion  40  and into the bulk of the body  42  of the earcushion  40 . The earcushion  40  may thus absorb acoustic energy generated or transmitted into a volume defined between the earcup  14  of a headphone  10  and the head or ear of a user, for example, sound rendered by an acoustic driver of the headphone  10  and reflected from the ear or head of the user, or any other reverberant acoustic energy present within the earcup plenum. Absorption of such acoustic energy may increase the quality of audio perceived by a user wearing a headphone  10  fitted with the earcushion  40 . 
     In some examples, as illustrated in  FIG. 6F , the rear surface  52  of the body  42  of the earcushion  40  may include one or more cavities or depressions  56  extending from the rear surface  52  of the body  42  into the bulk of the body  42 . The one or more cavities or depressions  56  may be circular, oval, square, rectangular, or randomly shaped. The one or more cavities or depressions  56  may serve to somewhat decouple the external side wall of the earcushion from the internal sidewall of the earcushion, thus reducing direct mechanical transfer of forces applied at the external sidewall to the internal sidewall as compared to a similar earcushion  40  lacking the one or more cavities or depressions  56 . The one or more cavities or depressions  56  may thus increase the comfort of the earcushion  40  for the wearer by making the earcushion “feel” softer. Similar cavities or depressions  56  may be defined in the earcushion  20 . 
     As illustrated in  FIG. 6E , an acoustic damper  54  may be embedded within the body  42  of the earcushion  40  (in this example, at or near the cross-sectional center of the body  42  of the earcushion  40 ). The acoustic damper  54  may be embedded at a substantially central location in the body  42  of the earcushion  40  as illustrated, although in alternate examples an acoustic damper  54  may alternatively or additionally be located proximate upper, lower, inner, or outer surfaces of the body  42  of the earcushion  40  or proximate or in contact with the snap ring  44 . The acoustic damper  54  may include or consist of a material having a density greater than a density of the partially reticulated polymeric foam forming the body  42  of the earcushion  40 . The material of the acoustic damper  54  may include, for example, silicone, metals, ceramics or other materials having a density greater than a density of the partially reticulated polymeric foam forming the body  42  of the earcushion  40 . The acoustic damper  54  may be a ring or a rope having a substantially oval or circular shape. Alternatively, the acoustic damper  54  may be embedded as a high-density powder (e.g., a metal powder) dispersed throughout the body  42  of the earcushion  40  at regular or random intervals. The acoustic damper  54  may increase the effective density of the body  42  of the earcushion  40  to substantially attenuate the acoustic signal from outside the earcushion  40  that passes through the earcushion  40  to the ear of the user as compared to a similar earcushion  40  without the acoustic damper  54 . 
     In further implementations, the body  42  of the earcushion  40  may include a hollowed-out portion or molded cavity  58 , as illustrated in  FIG. 6G . The hollowed-out portion or molded cavity  58  may render the body  42  of the earcushion  40  substantially U-shaped. The hollowed-out portion or molded cavity  58  may increase the pliability of the earcushion  40  as compared to a similar earcushion  40  without the hollowed-out portion or molded cavity  58 , rendering the earcushion  40  more comfortable for a user to wear. Such a hollowed-out portion or molded cavity may also be present in alternate examples of the earcushion  20 . The hollowed-out portion or molded cavity may be formed with different shapes, for example, a star-like shape or even a random shape, for example, as illustrated in  FIG. 6H . These random shapes may be designed to further enhance the listening experience of the user. 
     Having thus described several aspects of at least one implementation, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the spirit and scope of the disclosure. The acts of methods disclosed herein may be performed in alternate orders than illustrated, and one or more acts may be omitted, substituted, or added. One or more features of any one example disclosed herein may be combined with or substituted for one or more features of any other example disclosed. Accordingly, the foregoing description and drawings are by way of example only. 
     The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the term “plurality” refers to two or more items or components. As used herein, dimensions which are described as being “substantially similar” should be considered to be within about 25% of one another. The terms “comprising,” “including,” “carrying,” “having,” “containing,” and “involving,” whether in the written description or the claims and the like, are open-ended terms, i.e., to mean “including but not limited to.” Thus, the use of such terms is meant to encompass the items listed thereafter, and equivalents thereof, as well as additional items. Only the transitional phrases “consisting of” and “consisting essentially of,” are closed or semi-closed transitional phrases, respectively, with respect to the claims. Use of ordinal terms such as “first,” “second,” “third,” and the like in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.