Patent Publication Number: US-10321219-B2

Title: Earphone tip with universal sound port attachment core

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 62/271,521, filed on Dec. 28, 2015, the entire disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure pertains to sound devices and earphone tips for use with sound devices. More particularly, the present invention pertains to earphone tips for use with earbud-type headphones that provide a sturdy yet removable connection to the headphone for a wide range of sound port designs present on available headphones. 
     BACKGROUND 
     Sound devices such as headphones are used extensively throughout the world. One style of headphones that is commonly used is referred to as an earbud or an earbud-type headphone. Earbuds (i.e. earphones) are small speaker-like devices that are designed to fit within the external ear of a listener so that the user can listen to sound being transmitted from a sound source. Some examples of typical sound sources where earbuds may be used include personal and/or portable audio players (including radios, cassette players, compact disc players, portable mp3 players, etc.), portable DVD players, telephones (including wireless and cellular-type telephones), tablets, etc. When properly positioned in the ear, earbuds can provide the listener with acceptable sound transmission to the ear canal. Sound tubes or ports of earbuds are intended to channel sound transmitted from the driver (e.g., speaker) of the sound device into the ear canal of a user. Soft, flexible earphone tips have been developed for connection to a sound tube of an earbud which are configured to be received within the ear canal of a user to achieve a firm, yet comfortable fit for the user. Earphone tips must be replaced regularly. Therefore, the connection of the earphone tip to the sound tube must be detachable coupled, in other words, the user must be able to both position the earphone tip on the sound tube and remove/change the tip. When positioned on the sound tube the earphone tip/sound tube interface must provide sufficient retention to maintain the tip on the sound tube when in use, including during insertion and removal from the ear. However, there are currently many different earbud sound tube designs employing different configurations of earphone tip connection types for connection to the different sound tube configurations. Each of the earphone tips is typically designed to fit a single configuration of sound tube. If a user purchases replacement earphone tips not specifically designed for their earphone sound tube, the interface between the earphone tip and sound tube may be inadequate. With the wide range of sound tube designs on earbuds on the market there is a need for an earphone tip including design features that provide a universal connection regardless of design of the sound tube on the device. 
     SUMMARY 
     The present disclosure relates to sound devices and earphone tips for use with sound devices. 
     One exemplary embodiment is an earphone tip configured to be detachably coupled to an earbud-type sound device or other sound device, regardless of sound tube diameter and external surface features. The earphone tip includes an adapter body including a proximal portion and a distal portion having a lumen extending therethrough from a proximal end to a distal end along a central longitudinal axis. The adapter body also includes a lead-in face in the proximal portion of the lumen defined by a distally extending reduction in lumen diameter that aids insertion of the sound tube into the lumen. The reduction in diameter being from a larger diameter of about 4.0 mm (0.157 inches) to about 8.4 mm (0.330 inches) to a smaller diameter of about 2.0 mm (0.078 inches) to about 4.1 mm (0.161 inches) over an axial length of the lumen of about 0.5 mm (0.019 inches) to about 1.7 mm (0.067 inches). The adapter body further includes one or more retention members in the distal portion of the lumen. The one or more retention members extend radially inward within the lumen. The distal portion of the lumen has a diameter of about 3.0 mm (0.110 inches) to about 5.1 mm (0.200 inches) and the one or more retention members extend inward a distance of about 0.127 mm (0.005 inches) to about 1.5 mm (0.060 inches). The one or more retention members are located within a range of about 0.8 mm (0.030 inches) to about 1.8 mm (0.070 inches) from the proximal end of the lumen. 
     Additionally or alternatively to any of the embodiments above, the adapter body may further include a radially outwardly extending flange disposed proximate the proximal end of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the face slopes at an angle between 30 degrees and 60 degrees with respect to the central longitudinal axis. 
     Additionally or alternatively to any of the embodiments above, the face has a lower static coefficient of friction than the internal surface of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the face comprises a material having a lower static coefficient of friction than the static coefficient of friction of the material of the internal surface of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the face is coated with a material having a lower static coefficient of friction than the static coefficient of friction of the material of the internal surface of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the one or more retention members are located a distance from the proximal end that is less than forty percent of a distance between the proximal end and the distal end of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the one or more retention members project from the internal surface at an angle between 30 degrees and 150 degrees. 
     Additionally or alternatively to any of the embodiments above, the adapter body comprises a material having a Shore hardness value between 40 A and 80 A. 
     Additionally or alternatively to any of the embodiments above, the adapter body is formed of a material having a Shore hardness of 40 A to 65 A, a tensile modulus at 100% elongation of 350 psi or less, or less than 350 psi, and a static coefficient of friction of 0.75 to 2.5. 
     Additionally or alternatively to any of the embodiments above, the adapter body comprises a longitudinally extending groove in an outer surface of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the earphone tip further comprises a cushion circumferentially surrounding the adapter body and configured to frictionally engage an ear canal of a user. 
     Additionally or alternatively to any of the embodiments above, the cushion is formed as a monolithic structure with the adapter body. 
     Additionally or alternatively to any of the embodiments above, the cushion and the adapter body are made of a silicone material. 
     Additionally or alternatively to any of the embodiments above, the cushion is formed of a polymeric foam material. 
     Another exemplary embodiment is an earphone tip configured to be detachably coupled to a sound port of an earbud-type sound device or other sound device, regardless of sound port design. The earphone tip includes an adapter body extending from a proximal end to a distal end, wherein an internal surface of the adapter body defines a lumen extending through the adapter body along a central longitudinal axis. The proximal end of the adapter body extends a first distance radially from the longitudinal axis and the distal end of the adapter body extends a second distance radially from the longitudinal axis, the first distance being greater than the second distance. The lumen further defines an axially extending proximal portion and a distal portion. The adapter body also includes a lead-in face in the proximal portion of the lumen defined by a distally extending reduction in lumen diameter that aids insertion of the sound tube into the lumen. The reduction in diameter being from a larger diameter of about 4.0 mm (0.157 inches) to about 8.4 mm (0.330 inches) to a smaller diameter of about 2.0 mm (0.078 inches) to about 4.1 mm (0.161 inches) over an axial length of the lumen of about 0.5 mm (0.019 inches) to about 1.7 mm (0.067 inches). The adapter body further includes one or more retention members in the distal portion of the lumen. The one or more retention members extend radially inward within the lumen. The distal portion of the lumen has a diameter of about 3.8 mm (0.150 inches) to about 5.1 mm (0.200 inches) and the one or more retention members extend inward a distance of about 0.127 mm (0.005 inches) to about 1.5 mm (0.060 inches). The one or more retention members are located within a range of about 0.8 mm (0.030 inches) to about 1.8 mm (0.070 inches) from the proximal end of the lumen. 
     Additionally or alternatively to any of the embodiments above, the inwardly extending face has a lower static coefficient of friction than the internal surface of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the inwardly extending face slants away from the proximal end of the adapter body at an angle of between 30 degrees and 60 degrees. 
     Additionally or alternatively to any of the embodiments above, the adapter body comprises a plastic material. 
     Additionally or alternatively to any of the embodiments above, the plastic material has a Shore hardness of 40 A to 65 A, a tensile modulus at 100% elongation of 350 psi or less, and a static coefficient of friction of 0.75 to 2.5. 
     Additionally or alternatively to any of the embodiments above, the inwardly extending face extends toward the distal end of the adapter body to a point a distance away from the proximal end that is between 10% and 40% of a distance between the proximal end of the adapter body and the distal end of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the adapter body has a longitudinally extending groove formed in an exterior surface of the adapter body. Yet another exemplary embodiment is an earphone tip detachably coupleable to an earbud-type sound device or other sound device. The earphone tip includes an adapter body and a cushion attached to the adapter body. The adapter body includes a lumen extending from a proximal end to a distal end along a central longitudinal axis. The cushion is configured to frictionally engage an ear canal of a user. The adapter body is configured to connect securely to any one of a plurality of different sound port configurations of an earbud-type sound device or other sound device. 
     Additionally or alternatively to any of the embodiments above, the adapter body further comprises an internal surface defining the lumen and an internal rim extending inwardly from the internal surface of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the adapter body further comprises a longitudinally extending groove formed in an exterior surface of the adapter body. 
     Additionally or alternatively to any of the embodiments above, the adapter body is formed of a material having a Shore hardness of 40 A to 65 A, a tensile modulus at 100% elongation of 350 psi or less, or less than 350 psi, and a static coefficient of friction of 0.75 to 2.5. 
     The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The Figures, and Detailed Description, which follow, more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an exemplary earbud and earphone tip; 
         FIGS. 2A-2D  are plan views of exemplary sound ports that may be used in conjunction with an earphone tip of the present disclosure; 
         FIG. 3  is a perspective view of an adapter of the present disclosure; 
         FIG. 4  is a another perspective view of an adapter of the present disclosure including a groove; 
         FIG. 5  is a another perspective view of an adapter of the present disclosure including multiple grooves; 
         FIG. 6  is a plan view of an exemplary groove include groove dimensions; 
         FIG. 7A  is a cross-section view of the adapter of  FIG. 3  as viewed along line A-A of  FIG. 4 ; 
         FIG. 7B  is a cross-section view of an alternative design of the adapter of  FIG. 3  as viewed along line A-A of  FIG. 4 ; 
         FIG. 7C  is a cross-section view of an alternative design of the adapter of  FIG. 3  as viewed along line A-A of  FIG. 4 ; 
         FIG. 7D  is another perspective view of an adapter of the present disclosure including alternative retention members; 
         FIG. 7E  is a cross-section view of the adapter of  FIG. 7D ; 
         FIG. 7F  is another perspective view of the adapter of the present disclosure including another alternative design for retention members; 
         FIG. 7G  is a cross-section view of an alternative design of the adapter of  FIG. 3 ; 
         FIG. 7H  is a cross-section view of the adapter of  FIG. 7G  including a foam ear tip; 
         FIG. 8  is a plan view of an exemplary sound port and cross-sectional view of an adapter of the present disclosure illustrating alignment of the adapter with the sound port; 
         FIGS. 9A-9D  are plan views of the exemplary sound ports of  FIGS. 2A-2D  with an exemplary adapter coupled thereto; 
         FIGS. 10A and 10B  are different perspective views of an exemplary earphone tip incorporating an adapter of the present disclosure; 
         FIG. 11  is a cross-section view of the earphone tip of  FIG. 10B  as viewed along line B-B of  FIG. 10B ; 
         FIG. 12  is a perspective view of another exemplary earphone tip incorporating an adapter of the present disclosure; and 
         FIG. 13  is a cross-section view of the exemplary earphone tip of  FIG. 12  as viewed along line C-C of  FIG. 12 . 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION 
     For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. 
     All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (e.g., having the same function or result). As used herein, the use of the term “about” with numerical values includes numbers that are rounded to the nearest significant figure. 
     The recitation of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). 
     As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     It is noted that references in the specification to “an embodiment”, “some embodiments”, “other embodiments”, etc., indicate that the embodiment described may include one or more particular features, structures, and/or characteristics. However, such recitations do not necessarily mean that all embodiments include the particular features, structures, and/or characteristics. Additionally, when particular features, structures, and/or characteristics are described in connection with one embodiment, it should be understood that such features, structures, and/or characteristics may also be used connection with other embodiments whether or not explicitly described unless clearly stated to the contrary. 
     The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure. 
       FIG. 1  is a perspective view of an example earphone (i.e., earbud)  10  and earphone tip  12 . Earphone  10  may generally comprise a case or housing  13  which contains a speaker or driver  14 . The housing  13  may generally be formed from a plastic material and form a relatively rigid structure. In the example of  FIG. 1 , the housing  13  is generally cylindrical in nature, but this is just one example. In general, the housing  13  may take any shape or form to enclose components of the earphone  10 . 
     Wire  17 , also shown in  FIG. 1 , may enter the housing  13  along one side of the housing  13  and connect to the speaker or driver  14  within the housing  13 . Wire  17  can provide power and/or a sound signal to the speaker or driver  14 , and the speaker or driver  14  may produce sound based on the delivered power and/or sound signal. 
     One feature that may be common among earphones, as shown in  FIG. 1  with respect to earphone  10 , is the inclusion of a sound port. For instance, the earphone  10  includes a sound port or sound tube  15  extending outward from a distal portion of the housing  13 . The sound port  15  may generally direct sound produced by the speaker or driver  14  away from the speaker or driver  14  and out of the housing  13  through the sound port opening  18 . Structurally, the sound port  15  can be a generally cylindrical member projecting distally from the housing  13  and having a lumen extending therethrough to pass sound from the speaker or driver into the ear of the user. The outer surface of the sound port  15  in current designs include many features and shapes intended to aid in the interface between the sound port  15  and the ear tip  12  as described below with respect to  FIGS. 2A-2D . 
     The earphone  10  may generally be configured for insertion into the ear of a user with the sound port  15  extending toward (distally) and/or into an ear canal of the user. For example, a user may insert the sound port  15  and ear tip  12  combination into an ear canal in order to direct sounds generated by the speaker or driver  14  through the sound port  15 , out the sound port opening  18 , and into the ear canal. Due to the housing  13  being made from a solid material, inserting the sound port  15  directly into an ear canal can be uncomfortable. Accordingly, an earphone tip  12  may be connected to the sound port  15  for frictionally engaging the ear canal of the user, while at the same time providing varying degrees of external sound reaching the ear canal depending on the earphone tip  12  design. 
     The earphone tip  12  may be comprised of a soft, flexible material that is easily deformable. Accordingly, when a user inserts the earphone  10  into their ear with the earphone tip  12  connected, the earphone tip  12  may deform to fit within the ear canal and provide a soft, cushiony interface between the earphone  10  and the ear canal. The deformable nature of the earphone tip  12  may additionally frictionally engage the ear canal of the user to retain the earphone  10  in the user&#39;s ear and/or act to seal off ear canal, thereby reducing or eliminating noise external to earphone  10  from entering the ear canal. 
     The sound port  15  may include one or more external surface features on the generally cylindrical surface of the sound port  15  for connecting to an earphone tip, such as earphone tip  12 . In the example of  FIG. 1 , the sound port  15  includes a flange  16  located at or near the sound port opening  18  at the edge of the sound port  15  furthest away from the housing  13 . However, this is just one example connection feature that the sound port  15  may employ to connect to an earphone tip, such as earphone tip  12 . In general, the sound port  15  may include one of many different connection features, for example those depicted with respect to  FIGS. 2A-2D . 
       FIGS. 2A-2D  generally depict alternative example sound ports including different external surface or connection features for connecting to earphone tips.  FIG. 2A  depicts an exemplary sound port  25   a  connected to an exemplary housing  23   a . The sound port  25   a  may be categorized as a “barbed sound port.” The sound port  25   a  may have a length  31   a  (measured from a proximal end of the sound port  25   a , attached to the housing  23   a , to a free end of the sound port  25   a  along the central longitudinal axis of the sound port  25   a ) and a width or diameter  32   a  (measured perpendicular to the length  31   a , and thus the central longitudinal axis). 
     Additionally, the sound port  25   a  may include a barb or flange  26   a  generally disposed on the sound port  25   a  at a location between the sound port opening  28   a  and the housing  23   a . For instance, the side of the barb or flange  26   a  disposed most closely to the housing  23   a  may be a distance  33  away from the free end of the sound port  25   a  comprising the sound port opening  28   a . In other embodiments, the barb or flange  26   a  may be disposed directly at the free end of the sound port  25   a  adjacent the sound port opening  28   a . The barb or flange  26   a  may have a width or diameter  34  (measured perpendicular to the length  31   a , and thus the central longitudinal axis) that is generally greater than the width  32   a  of the sound port  25   a . In some embodiments, the length  31   a  of the sound port  25   a  may be generally greater than the width  34  of the barb or flange  26   a , however, in other embodiments the length  31   a  of the sound port  25   a  may be equal to or less than the width  34  of the barb or flange  26   a.    
       FIG. 2B  depicts another exemplary sound port  25   b  connected to an exemplary housing  23   b . The sound port  25   b  may be categorized as a “straight sound port.” In the example of  FIG. 2B , the sound port  25   b  does not include a barb or flange and provides a generally cylindrical outer surface over its length. For instance, the sound port  25   b  extends away from the housing  23   b  to a sound port opening  28   b  at a free end of the sound port  25   b  without any protrusions along its length. The sound port  25   b  may have a length  31   b  (measured from a proximal end of the sound port  25   b , attached to the housing  23   b , to a free end of the sound port  25   b  along the central longitudinal axis of the sound port  25   b ) and a width or diameter  32   b  (measured perpendicular to the length  31   a , and thus the central longitudinal axis). 
       FIG. 2C  depicts another exemplary sound port  25   c  connected to an exemplary housing  23   c . The sound port  25   c  may be categorized as a “cone sound port”. In the embodiment of  FIG. 2C , instead of including a barb or flange located along the sound port  25   c , the sound port  25   c  includes a recess or groove  40  located between a proximal end of the sound port  25   c  and a tapered cone portion proximate the free end of the sound port  25   c . In some instances, the recess or groove  40  may extend continuously around the entire perimeter or circumference of the sound port  25   c . However, in other instances, the recess or groove  40  may extend discontinuously around only a portion of the perimeter or circumference of the sound port  25   c . The sound port  25   c  may generally extend away from the housing  23   c  toward a sound port opening  28   c  at a free end of the sound port  25   c . The sound port  25   c  may have a length  31   c  (measured from a proximal end of the sound port  25   c , attached to the housing  23   c , to a free end of the sound port  25   c  along the central longitudinal axis of the sound port  25   c ) and a width or diameter  32   c  (measured perpendicular to the length  31   c , and thus the central longitudinal axis). However, the base of the recess or groove  40  of the sound port  25   c  may have a reduced width, represented by width or diameter  36 , which is less than the width  32   c . In at least some of these embodiments, the housing  23   c  may include an extension  42  that connects to the sound port  25   c . As depicted in  FIG. 2C , the extension  42  may have a greater width or diameter than both the width  32   c  of the sound port  25   c  and the width  36  of the base of the recess or groove  40 . 
     The sound port  25   c  may further include a tapered portion or cone proximate the free end of the sound port  25   c . For instance, as seen in  FIG. 2C , the sound port  25   c  may include a tapered portion extending between the recess or groove  40  and the free end of the sound port  25   c . The tapered portion or cone may taper to a smaller diameter as it extends away from the recess or groove  40  toward the free end of the sound port  25   c . For example, the cone or tapered portion of the sound port  25   c  may have a width  32   c  proximate the recess or groove  40  and a width  35  proximate the free end (e.g., proximate the sound port opening  28   c ) which is less than the width  32   c . The length  37  depicted in  FIG. 2C  is the length of the cone or tapered portion of the sound port  25   c.    
     In yet another embodiment,  FIG. 2D  depicts another exemplary sound port  25   d  and connected to an exemplary housing  23   d . The sound port  25   d  may be categorized as an “undercut sound port.” As with the sound port  25   c  of  FIG. 2C , the sound port  25   d  also includes a recess or groove  41 . In some instances, the recess or groove  41  may extend continuously around the entire perimeter or circumference of the sound port  25   d . However, in other instances, the recess or groove  41  may extend discontinuously around only a portion of the perimeter or circumference of the sound port  25   c . The sound port  25   d  may generally extend away from the housing  23   d  toward a sound port opening  28   d  at a free end of the sound port  25   d . The sound port  25   d  may have a length  31   d  (measured from a proximal end of the sound port  25   d , attached to the housing  23   d , to a free end of the sound port  25   d  along the central longitudinal axis of the sound port  25   d ). The sound port  25   d  may include a first portion (e.g., cylindrical portion) having a length  39  and a width or diameter  32   d  (measured perpendicular to the length, and thus the central longitudinal axis) and a second portion forming the recess or groove  41  that has a width or diameter  38  (measured perpendicular to the length, and thus the central longitudinal axis). As can be seen, the width  38  is less than width  32   d . Additionally, in some embodiments, the housing  23   d  may include an extension  43  that connects to the sound port  25   d . As depicted in  FIG. 2D , the extension  43  may have a greater width or diameter than both of the width  32   d  of the cylindrical portion of the sound port  25   d  and the width  38  of the base of the recess or groove  41 . 
     In general, the widths or diameters  32   a - 32   d  for sound ports  25   a - 25   d  may range from about 2.5 mm (0.10 inches) to about 7.6 mm (0.30 inches), and in other embodiments, the widths  32   a - 32   d  may be even greater than 7.6 mm (0.30 inches). Additionally, lengths  31   a - 31   d  may generally be greater than the width  32   a - 32   d  of the respective sound ports  25   a - 25   d . For instance, the ratio of width  32   a - 32   d  to length  31   a - 31   d  of the sound port  25   a - 25   d  may be about 0.75 or less, about 0.65 or less, or about 0.55 or less, in some instances. However, in some embodiments, the ratio of width  32   a - 32   d  to length  31   a - 31   d  may approach 1 and or exceed 1 (e.g., the width  32   a - 32   d  may be equal to or approximately equal to the length  31   a - 31   d ). Absent the use of an earphone tip specifically dimensioned and designed to fit a designated sound tube it is readily apparent that a mismatch may provide inadequate tip retention in use. 
       FIG. 3  is a perspective view of a universal sound port core or adapter  100  for use with a removable/replaceable earphone tip for a sound device that provides a sturdy yet detachable connection to a wide range of sound ports. The core or adapter  100  may be configured to connect securely to any one of a plurality of different sound port configurations of an earbud-type sound device or other sound device. For example, the core or adapter  100  may be configured to connect securely to at least each of the sound ports depicted in  FIGS. 2A-2D  so that individual earphone tips do not need to be designed specifically for each sound port having a different connection feature. 
     Generally, the core or adapter  100  may include a body  101  that extends along a central longitudinal axis  110  from a first, proximal end  102  (at the base of the core  100 ) to a second, distal end  103  (at the tip of the core  100 ). In some embodiments, the body  101  may generally have a cylindrical shape. However, in other embodiments, the body  101  may have any desirable shape, such as rectangular, ovoid, conic, or the like. In some embodiments, as described below, the core  100  includes a proximal portion that provides structure and material properties for allowing insertion of a wide range of radial diameter sound ports and a distal portion that includes structure for retaining the core  100  on sound ports having different outside surface features as previously described with respect to  FIGS. 2A-2D , above. 
     In some embodiments, the body  101 , at the proximal end  102 , may include a flange  104  extending radially outward from a main portion of the body  101 . The flange  104  may be wider (e.g., have a greater diameter) than the remainder of the body  101  (e.g., the main portion of the body  101 . The adapter or core  100  may include lead-in face  105  radially inward of the flange  104  proximate the proximal end  102  of the adapter  100 . Lead-in face  105  may comprise a surface that tapers inwardly from the flange  104  toward a center of the body  101  and the central longitudinal axis  110  in a direction from the proximal end  102  toward the distal end  103  of the core  100 . The lead-in face can be a feature of the proximal portion of the core  100  that aids in insertion of a wide range of outer diameters found on sound tube. In some embodiments, as shown in  FIG. 3 , the lead-in face  105  may slope radially inward away from the proximal end  102  toward the distal end  103  as the lead-in face  105  extends inward, terminating at an internal rim  106  that is a structural feature of the distal portion of the core  100  that provides earphone tip retention for a wide variety of outer surface features of sound tubes. The internal rim  106  may define an opening  107  that leads to a lumen  109  defined by the main portion of the body  101 . In this configuration, the lead-in face  105  may define an outline of a frustoconical shape between the proximal end  102  and the opening  107 . The internal rim  106  may extend continuously or discontinuously around the interior of the adapter  100 , as described in more detail below with respect to alternative embodiments. 
       FIG. 4  depicts another perspective view of the adapter  100 . As can be seen in  FIG. 4 , in some embodiments, the body  101  may include a longitudinally extending groove  108  extending into the main portion of the body  101  from an exterior surface of the main portion of the body  101  to the adapter  100 . The groove  108  may weaken one or more mechanical features of the body  101  such that the body  101  may flex more easily (e.g., radially expand) when forces are applied to the sides of the body  101  or to the flange  104  (e.g., when a sound port positioned in the lumen  109  exerts a radially outward force on the interior surface of the main portion of the body  101  defining the lumen  109  and/or the internal rim  106 . This feature may make it easier to connect and disconnect the adapter  101  from a sound port, such as those described with respect  FIGS. 2A-2D . 
     Of course, although shown in  FIG. 4  as only including a single longitudinal groove  108 , in other embodiments, the body  101  may include a plurality longitudinal grooves  108  symmetrically or asymmetrically arranged around the periphery or circumference of the main portion of the body  101  of the adapter  100 . As one example, the body  101  may include two longitudinal grooves  108  that are situated on opposite sides of the body  101 .  FIG. 5  depicts another sound port adapter  120  including additional longitudinal grooves  128 . The embodiment of  FIG. 5  depicts eight separate longitudinal grooves  128  spaced around the circumference of the body  121 . However, this is just one example. In general the sound port adapter  100  or  120  may include any number of longitudinal grooves, as desired. Generally, the more longitudinal grooves implemented on the body  101 ,  121  of an adapter  100 ,  120  of the present disclosure, the more easily the body  101 ,  121  of the adapter  100 ,  120  may flex and/or radially expand when forces (e.g., radially outward forces) are applied to the body  101 ,  121 . 
       FIG. 6  depicts a cross-section of a portion of the body  101  including a longitudinal groove  108  showing relative dimensions between the cylindrical wall of the body  101  and the groove  108 . It is noted that discussion of the groove  108  of  FIG. 6  would also be applicable to the grooves  128  of the embodiment of  FIG. 5 , and other embodiments including grooves disclosed herein. In different embodiments of the present disclosure, the dimensions of the groove  108 , or the dimensions of each of multiple grooves in embodiments that include multiple grooves (e.g., the embodiment of  FIG. 5 ), may be different relative to the dimensions of the body  101 . For instance, in some instances the width  112  of the groove  108  may be between about 0.001 inch to about 0.050 inch, about 0.010 inch to about 0.050 inch, about 0.010 inch to about 0.30 inch, about 0.015 inch to about 0.025 inch, or about 0.02 inches. However, in still further embodiments, the width  112  of the groove  108  may extend the majority of the circumference of body  101  such that the width  112  of the groove  108  is between 50% and 95% percent of the circumference of body  101 , for example. Similarly, in embodiments that include multiple grooves, the width  112  of each groove  128  (measured in a circumferential direction) may range anywhere between 0.5% and 50%, between 0.5% and 40%, between 0.5% and 30%, between 0.5% and 20%, between 0.5% and 10%, between 1% and 50%, between 1% and 40%, between 1% and 30%, between 1% and 20%, between 1% and 10%, between 2% and 50%, between 2% and 40%, between 2% and 30%, between 2% and 20%, between 2% and 10%, between 5% and 50%, between 5% and 40%, between 5% and 30%, between 5% and 20%, or between 5% and 10%, of the circumference of the main portion of the body  101  in some instances. Additionally or alternatively, the combined width of all of the grooves  128  may range between 5% and 95%, between 5% and 80%, between 5% and 70%, between 5% and 50%, between 10% and 75%, between 10% and 50%, between 20% and 75%, or between 20% and 50% of the circumference of the main portion of the body  101 , for example. As with the number of grooves, the width chosen for a groove or a plurality of grooves may affect the mechanical properties of the body  101 . For instance, generally, the greater the width of a groove, or the greater the combined width of all included grooves, the more flexibility the body  101  may have. 
     Depth  114  (measured in a radial direction perpendicular to the central longitudinal axis  110 ) in  FIG. 6  defines how deep groove  108  may extend into the wall of the body  101  from the outer peripheral surface of the main portion of the body  101 . In some instances, the depth  114  may be between 0.1 mm (0.004 inches) to 0.5 mm (0.020 inches), between 0.1 mm (0.004 inches to 0.25 mm (0.010 inches), between 0.05 mm (0.002 inches) to 0.5 mm (0.020 inches), or 0.05 mm (0.002 inches) to 0.5 mm (0.020 inches). In different embodiments, depth  114  may range from between 5% to 95%, between 5% to 75%, between 5% to 50%, between 10% to 75%, between 10% to 50%, between 10% to 40%, between 10% to 30%, between 10% to 20%, between 20% to 40%, between 20% to 30%, about 10%, about 20%, or about 30% of the wall thickness T (measured in a radial direction perpendicular to the central longitudinal axis  110 ) of body  101 , for example. The specific depth  114  chosen may affect the mechanical properties of the body  101 . For instance, generally, the greater the depth  114 , the more flexible the body  101  may be. 
     It is noted that in other embodiments the groove(s)  108  may extend into the wall of the body  101  from the inner peripheral surface of the main portion of the body  101  toward the outer peripheral surface of the main portion of the body  101 , if desired. 
       FIGS. 7A-H  each depict an exemplary perspective or cross-section of alternative designs of adapter or core  100  of  FIG. 3  or  FIG. 4  as viewed along line A-A, including various embodiments and dimensions of the adapter  100 . The views of  FIGS. 7A, 7B, 7C, 7E  and  FIG. 7G  provide features that delineate a proximal portion  168  of the core  100  and a distal portion  169  of the core  100  that make ear tips incorporating these features a universal design for detachably coupling to a wide range of sound tube designs. In general, width  141  may define the overall width (e.g., diameter) of the adapter  100  at the proximal end  102 , while width  172  may define the overall width (e.g., diameter) of the adapter  100  at the distal end  103 . Generally, the width  141  may be greater than the width  172 , as the proximal end  102  may include the flange  104 . Thus, in some instances the width  141  may be the outer diameter of the flange  104  at the proximal end  102 . In the embodiment of  FIG. 7G , the overall width  141  at the proximal end  102  may be about 8.5 mm (0.33 inches) to about 9.0 mm (0.35 inches), or about 8.75 mm (0.34 inches), while the overall width  172  at the distal end  103  may be about 6.5 mm (0.25 inches) to about 7.5 mm (0.30 inches), or about 7.0 mm (0.275 inches), for example. 
     Additionally, the body wall thickness  173  represents the thickness of the wall of body  101  and may generally range anywhere between about 0.38 mm (0.015 inches) to about 1.27 mm (0.050 inches), and more specifically between about 0.51 mm (0.020 inches) to about 1.02 mm (0.040 inches). In some embodiments, as depicted in  FIGS. 7A, 7B, 7C, 7E and 7G , the exterior surface of the main portion of the body  101  of the adapter  100  may taper from a first, larger diameter proximate the proximal end  102  to a second, smaller diameter proximate the distal end  103 . Additionally or alternatively, the interior surface  113  of the main portion of the body  101  of the adapter  100  defining the lumen  109  may have a constant diameter or may taper from a first diameter proximate the proximal end  102  to a second diameter proximate the distal end  103 . The first diameter of the interior surface  113  may be greater than or less than the second diameter of the interior surface  113 , as desired. In such embodiments, the value of the wall thickness of the body  101  may vary as well from a larger wall thickness near the proximal end  102  to a smaller wall thickness  173  at the distal end  103 . 
     Flange width  143  may represent the width of flange  104  as it extends radially outward from the exterior surface of the main portion of the body  101 . The flange width  143  may be between about 0.2 mm (0.008 inches) to about 2 mm (0.079 inches), between about 0.4 mm (0.016 inches) to about 2 mm (0.079 inches), or between about 0.5 mm (0.020 inches) to about 1 mm (0.039 inches), in some instances. In the embodiment of  FIG. 7G , the flange width  143  may be about 0.6 mm (0.02 inches) to about 1.0 mm (0.04 inches), or about 0.8 mm (0.03 inches), for example. 
     Additionally, flange  104  may have a flange height  142 , while the adapter  100  has an overall body height  170 . In some instances, the flange height  142  may be between about 0.2 mm (0.008 inches) to about 2 mm (0.079 inches), between about 0.4 mm (0.016 inches) to about 2 mm (0.079 inches), or between about 0.5 mm (0.020 inches) to about 1 mm (0.040 inches). In some instances, the flange height  142  may be 1.2 mm (0.047 inches) or less, 1.1 mm (0.043 inches) or less, 1.0 mm (0.040 inches) or less, 0.9 mm (0.035 inches) or less, 0.8 mm (0.032 inches) or less, or 0.7 mm (0.028 inches) or less. In the embodiment of  FIG. 7G , the flange height  142  may be about 0.6 mm (0.02 inches) to about 0.9 mm (0.04 inches), or about 0.75 mm (0.03 inches), for example. In some instances, the overall body height  170  may be between about 3 mm (0.118 inches) to about 16 mm (0.630 inches), between about 5 mm (0.197 inches) to about 12 mm (0.472 inches), between about 7 mm (0.276 inches) to about 10 mm (0.394 inches), or between about 7 mm (0.276 inches) to about 8 mm (0.315 inches). In the embodiment of  FIG. 7G , the overall height  170  may be about 3.5 mm (0.138 inches) to about 3.7 mm (0.146 inches), or about 3.65 mm (0.144 inches), fore example. As with flange width  143 , in different embodiments, the relation between the flange height  142  and the overall body height  170  may differ. 
     In each of the embodiments depicted in  FIGS. 7A-H , the core or adapter  100  includes a lumen  109  extending from the proximal end to the distal end thereof. The walls defining this lumen and the materials used to form the core  100  include elements that allow the positioning and detachable retention of the ear tip onto sound tubes having a wide range of sizes and shapes. Further, the walls defining the lumen  109  include other elements that aid in adequately retaining the ear tip for a wide range of sound tube sizes and shapes. The core or adapter  100  includes a proximal portion  168  having a lead-in face  105  and a distal portion  169  having a proximally located retention member and or members  106 . The combination of these features can make the core  100  and associated ear tip a universal fit for current ear phones having various sound tube design features and sizes. 
     Referring specifically to  FIG. 7A , the proximal portion  168  of the core  100  can extend from the proximal end  102  distally a length of about 0.5 mm. to about 1.5 mm. The lead-in face  105 , which can aid in positioning sound tubes of various size and design within the lumen  109 , is included in the proximal portion  168 . As mentioned previously, at the proximal end  102 , the lead-in face  105  may taper or slope radially inwardly from the proximal end  102  toward the distal end  103 . Accordingly, the lead-in face  105  may define an opening that has a width  165  at the proximal end  102  and tapers toward the distal end  103  to an intermediate width  167 , which in the embodiment of  FIG. 7A  marks the distal end of the proximal portion  168 . As shown in the illustrated embodiment, the width  167  along the face  105  may be the same as the width  171  of the lumen  109  in the distal portion  169  described below. In the embodiment of  FIG. 7A , the lead-in face  105  continues to taper inward in the distal portion  169  down to opening  107 , which has a width  161 . In some embodiments, width  165  can be from about 4.3 mm (0.170 inches) to about 8.40 mm (0.330 inches), while width  167  can be about 2.79 mm (0.10 inches) to about 5.08 mm (0.20 inches), and width  161  can be about 2.0 mm (0.079 inches) to about 4.1 mm (0.161 inches). In different embodiments, width  161  and width  165  may be related in different fashions. 
     Additionally, as the lead-in face  105  extends radially inwardly and toward the distal end  103 , the lead-in face  105  may form an angle  162  with respect to the central longitudinal axis of the body  101 . Alternatively, the lead-in face  105  can be defined in terms of the length axially over which the reduction in diameter decreases. Width  165  can reduce to width  161  over an axial length (length  163  in  FIG. 7A ) of about 0.8 mm (0.032 inches) to about 1.5 mm (0.059 inches). In different embodiments, angle  162  may range anywhere between about 30° to about 60°, between about 30° to about 50°, between about 40° to about 60°, or between about 40° to about 50°, for example. The specific value chosen for the axial length over which the diameter or width is reduced or the angle  162  may affect how easily adapter  100  may connect to a sound port and/or may affect the largest size of sound tube the earphone tip having the adapter  100  may reasonably accept. The lead-in face  105  can include a linear surface or a curved surface to achieve its function which is to direct the sound tube gradually into the lumen  109  while stretching or expanding the core material to receive the sound tube therein. 
     Also as mentioned previously, the distal portion  169  of the lumen  109  can include a defining surface that has one or more retention members projecting radially inward from the lumen wall. In the embodiment of  FIG. 7A , the retention member is defined on the proximal side by the continued reduction in diameter of the lead-in face from diameter  167  to diameter  161 . As indicated, the opening  107  can be defined by an internal rim  106  extending radially inward from the interior surface  113  of the wall of the main portion of the body  101  defining the lumen  109  in the distal portion  169 . In some embodiments, the wall of the distal portion  169  defining the lumen  109  can include a diameter or width of about 2.8 mm (0.110 inches) to about 5.08 mm (0.20 inches). Internal rim  106 , which is disposed a distance away from interior surface  113 , may form a shoulder  111  facing the distal end  103  of the body  101 . The shoulder  111  may be configured to engage a surface or feature of a sound port to facilitate retention of the adapter  100  on the sound port. For example, the shoulder  111  may engage a surface of an annular barb or recess of a sound port to provide an interference fit therebetween. 
     Referring now to the embodiment depicted in  FIG. 7B , an alternative design for the proximal portion  168  is depicted. In this embodiment, the proximal end width  165  of the lumen  109  extends distally with a constant diameter (i.e., is cylindrical) for a portion of the proximal section  168  before beginning to taper inwardly to form the lead-in face  105 . Thus, the proximal end of the lead-in face  105  is recessed distally from the proximal end  102  of the adapter  100 . 
     Referring now to the embodiment depicted in  FIG. 7C , another alternative design for the retention member in the distal portion  169  is depicted. In this embodiment, the retention member proximal side is not formed by a continuing taper of the lead-in face  105 . Instead, the lead-in face  105  of the proximal portion  168  ends at width  167  and the retention member is then formed by a rim projecting radially inward on both its proximal and distal side to form an annular rim or shoulder. 
     Another alternative embodiment may combine the features of the proximal portion  168  of  FIG. 7B  (having a proximal end of the lead-in face  105  recessed distally from the proximal end  102  of the adapter  100 ) and the features of the retention member in the distal portion  169  of  FIG. 7C  (proximal face of the retention member  106  not formed by a continuing taper of the lead-in face  105 , but rather a radially inward projecting surface). 
       FIGS. 7D-7F  depict alternative retention member designs. In previous embodiments the retention members were depicted as a continuous annular rim that projects radially inward within the lumen  109  to contact the sound tube or fit within a notch or groove in the sound tube. Alternatively, the retention member can be a discontinuous rim, such as a plurality of radially inwardly projecting fingers or sections  178  around the circumference with a cut-out or notch  177  between adjacent fingers  178 , rather than a continuous shoulder. The number of fingers, cut-outs or notches can vary in alternative embodiments. The fingers  178  in the distal portion  169  of the lumen  109  in  7 D- 7 F can extend a radial distance  176  inward from interior surface  113  between greater than 0.0 mm to about 1 mm in some instances, however; they should not be larger than dimension  151 , described herein. For instances, the radial dimension  176  of the fingers  178  may range between about 0.125 mm (0.005 inches) to about 1.5 mm (0.060 inches), and more specifically between about 0.125 mm (0.005 inches) to about 0.75 mm (0.030 inches), in some embodiments. It is contemplated that the adapter  100  may include a single cut-out  177  or a plurality of cut-outs  177 . These cut-outs  177  between fingers  178  could be of various sizes, such as a slit in the material between adjacent fingers  178  to encompassing a large percentage of the rim, as illustrated in  7 F. 
     Referring now to the embodiment depicted in  FIG. 7G , another alternative design for the retention member in the distal portion  169  is depicted. The core or adapter  100  includes a proximal portion  168  having a lead-in face  105  and a distal portion  169  having a proximally located retention member and or members  106 , such as a radially inwardly projecting rim. The lead-in face  105  may taper or slope radially inwardly from the proximal end  102  toward the distal end  103 . The combination of these features can make the core  100  and associated ear tip a universal fit for current ear phones having various sound tube design features and sizes. In this embodiment, the lead-in face  105  of the proximal portion  168  ends at width  167  and the retention member is then formed by a rim projecting radially inward on both its proximal and distal side to form an annular rim or shoulder. The embodiment of  FIG. 7G  is similar in many respects to the embodiment of  FIG. 7C . However, the overall height  170 , which may be attributed to a reduction in the length of the distal portion  169 , may be less than the overall height  170  of the embodiment of  FIG. 7C . In the embodiment of  FIG. 7G , the overall height  170  may be about 3.5 mm (0.138 inches) to about 3.7 mm (0.146 inches), or about 3.65 mm (0.144 inches), wherein the distal portion  169  may have a height of about 2.3 mm (0.091 inches) to about 2.5 mm (0.098 inches), or about 2.4 mm (0.094 inches), and the proximal portion  168  may have a height of about 1.2 mm (0.047 inches) to about 1.4 mm (0.055 inches), or about 1.3 mm (0.051 inches). 
     The lead-in face  105  may define an opening that has a width  165  at the proximal end  102  and tapers toward the distal end  103  to an intermediate width  167 , which in the embodiment of  FIG. 7G  marks the distal end of the proximal portion  168 . The proximally facing surface  175  of the retention member  106  (e.g., annular rim), may be located at the junction between the proximal portion  168  and the distal portion  169 . The annular rim of the retention member  106  may extend radially inward on both its proximal and distal sides. The lumen  109  of the distal portion  169  can have a diameter  171  of about 4.4 mm (0.17 inches) to about 4.8 mm (0.19 inches), or about 4.6 mm (0.18 inches). Internal rim  106 , which is disposed a distance away from interior surface  113 , may form a shoulder  111  facing the distal end  103  of the body  101 . The shoulder  111  may be configured to engage a surface or feature of a sound port to facilitate retention of the adapter  100  on the sound port. For example, the shoulder  111  may engage a surface of an annular barb or recess of a sound port to provide an interference fit therebetween. 
     Additionally, the lead-in face  105  may form an angle  162  with respect to the central longitudinal axis of the body  101 . The angle  162  may be about 50° to about 60°, or about 55°, for example. The specific value chosen for the axial length over which the diameter or width is reduced or the angle  162  may affect how easily adapter  100  may connect to a sound port and/or may affect the largest size of sound tube the earphone tip having the adapter  100  may reasonably accept. The lead-in face  105  can include a linear surface or a curved surface to achieve its function which is to direct the sound tube gradually into the lumen  109  while stretching or expanding the core material to receive the sound tube therein. 
     In the embodiment of  FIG. 7G , width  165  can be from about 7.0 mm (0.275 inches) to about 8.0 mm (0.315 inches), or about 7.6 mm (0.300 inches), while width  167  can be about 3.5 mm (0.138 inches) to about 4.5 mm (0.178 inches), or about 4.0 mm (0.157 inches), and width  161  can be about 3.5 mm (0.138 inches) to about 4.0 mm (0.157 inches), or about 3.7 mm (0.146 inches). 
     The internal rim  106  depicted in  FIGS. 7A, 7B, 7C, 7E and 7G , or other retention members, may have a height  164 , and in different embodiments the height  164  may range anywhere between about 0.125 mm (0.005 inches) to about 1.0 mm (0.040 inches), and more specifically between about 0.375 mm (0.015 inches) to about 0.635 mm (0.025 inches), or between about 0.635 mm (0.025 inches) to about 0.75 mm (0.030 inches), or about 0.75 mm (0.030 inches). However, in still other embodiments, the height  164  may be less than 0.125 mm (0.005 inches), greater than 1.0 mm (0.040 inches), or greater than 0.75 mm (0.030 inches). In the embodiment of  FIG. 7G , the height  164  may be about 0.6 mm (0.02 inches) to about 0.9 mm (0.04 inches), or about 0.75 mm (0.03 inches), for example. 
     The shoulder  111  may extend a distance  151  radially inward from the interior surface  113 . In different embodiments, the distance  151  may range between about 0.125 mm (0.005 inches) to about 1.5 mm (0.060 inches), and more specifically between about 0.125 mm (0.005 inches) to about 0.75 mm (0.030 inches) or between about 0.3 mm (0.01 inches) to about 0.5 mm (0.02 inches). However, in still other embodiments, the height  164  may be smaller than 0.125 mm (0.005 inches) or larger than 1.5 mm (0.060 inches). 
     The shoulder  111  may extend away from the interior surface  113  at an angle  152 . As depicted in  FIGS. 7A, 7B, 7C, 7E and 7G , the angle  152  may be 90°. However, in other embodiments, the angle  152  may range anywhere between about 30° to about 120°, between about 45° to about 100° between about 60° to about 120°, about 75° to about 105°, about 80° to about 100°, about 85° to about 95°, or another angle as desired. The specific value of the angle  152  may affect how adapter  100  connects to different sound ports. Another dimension depicted in  FIGS. 7A, 7B, 7C, 7E and 7G  is height  163 . Height  163  represents the distance between the closest edge (proximal edge) of the distal portion of retention member or exemplary internal rim  106  to the proximal end  102 . In some instances, the height  163  may be about 0.5 mm (0.020 inches) to about 2 mm (0.080 inches), about 0.75 mm (0.030 inches) to about 1.75 mm (0.070 inches), about 0.7 mm (0.028 inches), about 0.9 mm (0.035 inches), about 1.0 mm (0.040 inches), about 1.5 mm (0.060 inches), or about 1.6 mm (0.063 inches) for example. In the embodiment of  FIG. 7G , the height  163  may be about 1.1 mm (0.04 inches) to about 1.5 mm (0.06 inches), or about 1.3 mm (0.05 inches), for example. 
     In some instances, the height  163  (i.e., the distance between the proximal end  102  and the closest edge (proximal edge) of the internal rim  106 ) may be different than the flange height  142 . For instance, the height  163  may be greater than the flange height  142  in some embodiments such that the internal rim  106  is longitudinally offset distally from the flange  104 . In other embodiments, the height  163  may be less than or equal to the flange height  142  such that the internal rim  106  and the flange  104  are coextensive and/or longitudinally overlap one another. In some instances, the flange  104  may be located proximal of yet 1.0 mm (0.040 inches) or less, 0.9 mm (0.035 inches) or less, 0.8 mm (0.031 inches) or less, 0.7 mm (0.028 inches) or less, 0.6 mm (0.024 inches) or less, or 0.5 mm (0.020 inches) or less from the proximal edge of the internal rim  106 . In the embodiment of  FIG. 7G , the height  142  may be about 0.6 mm (0.02 inches) to about 0.9 mm (0.04 inches), or about 0.75 mm (0.03 inches), for example. 
     The flange  104  may provide a degree of rigidity to the adapter  100  proximate the internal rim  106  to help prevent unintentional decoupling of the adapter  100  from a sound tube of a sound device. For example, the flange  104 , located proximate the interior rim  106  may effectively increase the radial thickness of the adapter  100  proximate the interior rim  106 , restricting radial expansion of the adapter  100  proximate the interior rim  106  as the adapter  100  inserted over and/or removed from a sound port of a sound device, and thus increasing the retention force retaining the adapter  100  coupled to the sound port. 
     Additionally as depicted in  FIGS. 7A-7H , the opening  107  leads into the lumen  109  of the main portion of the body  101 . The lumen  109  may be defined by the interior surface  113  and may have diameter  171 . In some embodiments, the diameter  171  may be relatively constant from the opening  107  to the distal end  103 . However, in other embodiments, the diameter of the lumen  109  may vary from the opening  107  to distal end  103 . For example, the diameter  171  may transition from a larger diameter to a smaller diameter from the opening  107  toward the distal end  103 , or the diameter  171  may transition from a smaller diameter to a larger diameter from the opening  107  toward the distal end  103 . 
     The specific dimension chosen for the diameter  171  may be chosen to accommodate a range of sound port sizes. For instance, the diameter  171  may range anywhere between about 60% to about 125% of a chosen sound port diameter. In other instances, the diameter  171  may range anywhere between about 60% to about 110%, between about 60% to about 100%, between about 75% to about 125%, between about 75% to about 110%, or between about 75% to about 100% of a chosen sound port diameter. As one example, as mentioned above with respect to  FIGS. 2A-2D , widths  32   a - 32   d  of sound ports  25   a - 25   d  may range between about 0.10 inches to about 0.30 inches, for example. Accordingly, in these examples, the diameter  171  may be chosen to be accommodate a range of sound ports having a diameter between about 2.5 mm (0.10 inches) to about 7.6 mm (0.30 inches), for example. In some instances, the diameter  171  may be anywhere between about 1.3 mm (0.05 inches) to about 9.5 mm (0.375 inches), between about 1.5 mm (0.06 inches) to about 8.4 mm (0.33 inches), or between about 2.5 mm (0.1 inches) to about 7.6 mm (0.30 inches). 
       FIG. 7H  is a cross-section view of an earphone tip  400  including the adapter  100  of  FIG. 7G  and a cushion  410 , such as a foam cushion, secured to the adapter  100 . The cushion  410  may be formed of any desired resilient and/or foam material, such as a resiliently compressible polymeric foam material which may be compressed for insertion into the ear canal of a user and then undergo recovery towards its original size to closely conform to the surface of the ear canal. Some suitable foam materials include visco-elastic polyurethane foams and plasticized polyvinyl chloride foams. Other suitable polymeric foam materials are described in U.S. Pat. No. 8,327,973, which is herein incorporated by reference in its entirety. In some embodiments, the foam material may have an open cell structure, a closed cell structure, or a combination of open and closed cells, for example. The cushion  410  may have any desired shape, such as cylindrical, conical, frusta-conical, fluted, bulbous, convex, concave, or other desired shapes. 
     As shown in  FIG. 7H , the cushion  410  may surround the body of the adapter  100  with a proximal end of the cushion  410  abutting the distal surface of the flange  104 . Thus, the flange  104  may be positioned proximal of the proximal end  102  of the cushion  410 . A distal portion of the cushion  410  may extend distally beyond the distal end  103  of the adapter  100 . 
     The adapter  100  may be made from a number of different materials that impart different physical properties to the adapter  100 . In some embodiments, the adapter  100  may be made from any suitable material that may provide the adapter  100  with specific properties related to hardness, tensile modulus, and static and kinetic friction. For instance, the adapter  100  may be made from a material that results in the adapter  100  having a Shore durometer hardness value of between about 40 A to about 80 A, between about 40 A to about 70 A, between about 40 A to about 65 A, or between about 45 A to about 65 A, for example. 
     The material that the adapter  100  is formed from may also impart the adapter  100  with specific tensile modulus values at 100% elongation. For instance, the material may give the adapter  100  a tensile modulus of 450 psi or less at 100% elongation, 350 psi or less at 100% elongation, or 250 psi or less at 100% elongation. 
     The kinetic coefficient of friction of the material used to form the adapter  100  may be sufficiently low to facilitate sliding the adapter  100  onto a sound port while the static coefficient of friction may be sufficiently higher to facilitate retention of the adapter  100  to the sound port. The greater the differential between the static and coefficients of friction allows the adapter  100  to slip onto the sound port easily, while resisting movement therebetween during use. Sound ports are commonly made of a acrylonitrile butadiene styrene (ABS) material, thus coefficient of friction values provided herein are those between the material of the adapter  100  and a sound port formed of acrylonitrile butadiene styrene (ABS) having a surface finish of 10 Ra. 
     In some embodiments, the static coefficient of friction between the material used to form the adapter  100  and the material of the sound port may be between about 0.8 to about 3.5. In other embodiments, however, the static coefficient of friction may be between about 0.8 to about 2.2, between about 0.8 to about 2.0, between about 0.8 to about 1.5, between about 0.9 to about 1.1, or between about 0.9 to about 1.0, for instance. In some embodiments, the static coefficient of friction between the material of the adapter  100  and the material of the sound port may be about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9 or about 2.0, for example. 
     Additionally, it may be beneficial for the kinetic coefficient of friction between the material used to form the adapter  100  and the material of the sound port to be lower than the static coefficient of friction. This may allow the adapter  100  to be more easily slid on and connected to a sound port, while better maintaining the connection once in place. In some embodiments, the kinetic coefficient of friction between the material used to form the adapter  100  and the material of sound port may be between about 0.7 to about 2.0. In other embodiments, however, the static coefficient of friction may be between about 0.7 to about 1.5, between about 0.7 to about 1.25, between about 0.75 to about 1.5, between about 0.75 to about 1.25, or between about 0.75 to about 1.0, for instance. In some embodiments, the kinetic coefficient of friction between the material of the adapter  100  and the material of the sound port may be about 0.75, about 0.85, about 1.0, about 1.25, about 1.4, or about 1.5, for example. 
     Some example materials that may be used to form the adapter  100  that may give the adapter  100  the described properties include various plastic materials, including thermoplastic elastomers, such as Elastocon® 8048N from TPE Technologies, Inc., TCSMEZ from Kraiburg TPE, TC6MEZ from Kraiburg TPE, OnFlex™ 60 A from PolyOne Corp., and Santoprene™ thermoplastic vulcanizate (TPV) from Exxon Mobil Corp. 
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                   
                   
                 Tensile 
                   
                   
               
               
                   
                   
                 Modulus @ 
               
               
                   
                   
                 100% 
                 Static 
                 Kinetic 
               
               
                   
                 Hardness 
                 elongation 
                 Coefficient 
                 Coefficient of 
               
               
                 Material 
                 (Shore A) 
                 (psi) 
                 of Friction 
                 Friction 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Elastocon ® 
                 48 
                 232 
                 1.03 
                 0.74 
               
               
                 8048N 
               
               
                 TC5MEZ 
                 50 
                 310 
                 1.97 
                 1.43 
               
               
                 TC6MEZ 
                 61 
                 330 
                 1.88 
                 1.41 
               
               
                 OnFlex ™ 60A 
                 60 
                 319 
                 1.58 
                 1.27 
               
               
                 Santoprene ™ 
                 65 
                 305 
                 0.98 
                 0.83 
               
               
                 291 
               
               
                   
               
            
           
         
       
     
     In some instances, the material of the adapter  100  may have a Shore hardness of 60 A to 80 A, a tensile modulus at 100% elongation of 450 psi or less, or less than 450 psi, and a static coefficient of friction of 0.75 to 3.2. In some instances, the material of the adapter  100  may have a Shore hardness of 40 A to 70 A, a tensile modulus at 100% elongation of 450 psi or less, or less than 450 psi, and a static coefficient of friction of 0.75 to 3.2. In some instances, the material of the adapter  100  may have a Shore hardness of 40 A to 65 A, a tensile modulus at 100% elongation of 350 psi or less, or less than 350 psi, and a static coefficient of friction of 0.75 to 2.5. In some instances, the material of the adapter  100  may have a Shore hardness of 45 A to 65 A, a tensile modulus at 100% elongation of 325 psi or less, or less than 325 psi, and a static coefficient of friction of 0.75 to 2.0. In some instances, the material of the adapter  100  may have a Shore hardness of 45 A to 65 A, a tensile modulus at 100% elongation of 250 psi or less, or less than 250 psi, and a static coefficient of friction of 0.75 to 1.8. In some instances, the material of the adapter  100  may have a Shore hardness of 45 A to 50 A, a tensile modulus at 100% elongation of 300 psi or less, or less than 300 psi, and a static coefficient of friction of 0.9 to 1.1. In some instances, the material of the adapter  100  may have a Shore hardness of 60 A to 65 A, a tensile modulus at 100% elongation of 325 psi or less, or less than 325 psi, and a static coefficient of friction of 1.5 to 1.7. In some instances, the material of the adapter  100  may have a Shore hardness of 60 A to 65 A, a tensile modulus at 100% elongation of 310 psi or less, or less than 310 psi, and a static coefficient of friction of 0.9 to 1.0. 
     As shown in  FIG. 8 , a sound port may  180  be inserted through the proximal end  102  of the adapter  100  with the central longitudinal axis of the adapter  100  coaxially aligned with the central longitudinal axis of the sound port  180  of the sound device. During this connection process, the sound port  180  may initially contact the conical or funnel-shaped lead-in face  105 , prior to being advanced distally through the opening  107  and past the internal rim or retention member or members  106 , as the adapter  100  is being connected to the sound port  180 . The major diameter of the lead-in face  105  (i.e., the diameter proximate the proximal end  102 ) may be greater than or equal to the diameter of the largest sound port the adapter  100  is configured to be connected to. Furthermore, the minor diameter of the lead-in face  105  (i.e., the diameter proximate the interior rim  106 ), may be less than the diameter of the largest sound port the adapter  100  is configured to be connected to, yet the diameter  171  of the lumen  109  may be greater than the diameter of the smallest sound port the adapter  100  is configured to be connected to. 
     In some embodiments, it may be beneficial for the lead-in face  105  to have differing properties, particularly in relation to static and kinetic coefficients of friction, than other portions of the adapter  100 . Accordingly, the force required during the connection process to connect the adapter  100  to the sound port  180  may be reduced if the lead-in face  105  has relatively lower static and kinetic coefficients of friction. In some of these embodiments where the lead-in face  105  has relatively lower static and/or kinetic coefficients than other portions of the adapter  100 , the lead-in face  105  may be made from a different material than other portions of the adapter  100  and/or the remainder of the adapter  100 . In other embodiments, the lead-in face  105  may be formed from the same material as the rest of the adapter  100 , but may be coated with a different material that has relatively lower static and/or kinetic coefficients of friction, such as a slip coating. Some suitable coating materials for coating the lead-in face  105  include a polytetrafluoroethylene (PTFE) or silicone powder or spray. In still other embodiments, the lead-in face  105  may be patterned with a micro-texture that gives the lead-in face  105  relatively lower static and/or kinetic coefficients of friction. For example, the surface of the lead-in face  105  (attributed to a different material, coating layer, surface treatment or modification, etc.) may have a static coefficient of friction of 2.0 or less and a kinetic coefficient of friction of 1.5 or less, a static coefficient of friction of 1.75 or less and a kinetic coefficient of friction of 1.25 or less, a static coefficient of friction of 1.25 or less and a kinetic coefficient of friction of 1.0 or less, or a static coefficient of friction of 1.0 or less and a kinetic coefficient of friction of 0.85 or less, in some instances. 
       FIGS. 9A-9D  are plan views of the exemplary sound ports of  FIGS. 2A-2D , respectively, with an exemplary adapter or core  100 , shown in cross-section, coupled thereto. As shown in  FIG. 9A , the adapter  100  may be coupled to the sound port  25   a , with the sound port  25   a  extending through the opening  107  such that the interior rim  106  engages the barb  26   a  and provides an interference fit therewith. Thus, the opening  107  may have a diameter less than the diameter of the barb  26   a . In instances in which the diameter of the sound port  25   a  is greater than the diameter of the lumen  109  of the body of the adapter  100 , the exterior surface of the sound port  25   a  may additionally engage the interior surface  113  of the main body of the adapter  100  distal of the interior rim  106 . 
     As shown in  FIG. 9B , the adapter  100  may be coupled to the sound port  25   a , with the sound port  25   a  extending through the opening  107  with the interior rim  106  engaging the sound port  25   b . The opening  107  may have a diameter less than the diameter of the sound port  25   b  to provide an interference or frictional fit therewith to retain the adapter  100  on the sound port  25   b . In instances in which the diameter of the sound port  25   b  is greater than the diameter of the lumen  109  of the body of the adapter  100 , the exterior surface of the sound port  25   b  may additionally engage the interior surface  113  of the main body of the adapter  100  distal of the interior rim  106 . 
     As shown in  FIG. 9C , the adapter  100  may be coupled to the sound port  25   c , with the tapered cone portion of the sound port  25   c  extending through the opening  107  such that the interior rim  106  extends into the recess  40 . Thus, the opening  107  may have a diameter less than the diameter of the tapered cone portion of the sound port  25   c , while the diameter of the opening  107  may be less than or greater than the diameter of the recess  40  to provide an interference fit between the shoulder of the interior rim  106  and the edge of the recess  40  to retain the adapter  100  on the sound port  25   c . In instances in which the diameter  107  is less than the diameter of the recess  40 , the interior rim  106  may engage the base of the recess  40 . In instances in which the diameter of the tapered cone portion of the sound port  25   c  is greater than the diameter of the lumen  109  of the body of the adapter  100 , the exterior surface of the tapered cone portion of the sound port  25   c  may additionally engage the interior surface  113  of the main body of the adapter  100  distal of the interior rim  106 . 
     As shown in  FIG. 9D , the adapter  100  may be coupled to the sound port  25   d , with the cylindrical end portion of the sound port  25   d  extending through the opening  107  such that the interior rim  106  extends into the recess  41 . Thus, the opening  107  may have a diameter less than the diameter of the cylindrical end portion of the sound port  25   d , while the diameter of the opening  107  may be less than or greater than the diameter of the recess  41  to provide an interference fit between the shoulder of the interior rim  106  and the edge of the recess  41  to retain the adapter  100  on the sound port  25   d . In instances in which the diameter of the cylindrical portion of the sound port  25   d  is greater than the diameter of the lumen  109  of the body of the adapter  100 , the exterior surface of the cylindrical portion of the sound port  25   d  may additionally engage the interior surface  113  of the main body of the adapter  100  distal of the interior rim  106 . 
       FIGS. 10A and 10B  are perspective views of an earphone tip  200  including the adapter  100  and a cushion  210 , such as a foam cushion, secured to the adapter  100 . The cushion  210  may be formed of any desired resilient and/or foam material, such as a resiliently compressible polymeric foam material which may be compressed for insertion into the ear canal of a user and then undergo recovery towards its original size to closely conform to the surface of the ear canal. Some suitable foam materials include visco-elastic polyurethane foams and plasticized polyvinyl chloride foams. Other suitable polymeric foam materials are described in U.S. Pat. No. 8,327,973, which is herein incorporated by reference in its entirety. In some embodiments, the foam material may have an open cell structure, a closed cell structure, or a combination of open and closed cells, for example. The cushion  210  may have any desired shape, such as cylindrical, conical, frusta-conical, fluted, bulbous, convex, concave, or other desired shapes. 
       FIG. 11  depicts a cross-sectional view of the earphone tip  200  as viewed along line B-B of  FIG. 10B . As can be seen in  FIG. 11 , the cushion  210  may circumferentially surround the adapter  100 , with an interior surface of the cushion  210  secured (e.g., adhesively bonded or overmolded) to the peripheral/circumferential surface of the body  101  of the adapter  100 . The internal surface  202  of the cushion  210  may conform to the contour of the adapter  100 , and thus may, in some instances, include extensions  203  and/or cavities  205  that conform to the adapter  100 . In some instances, the cushion  210  may extend distal of the distal end of the adapter  100  to provide a soft, compliant tip for insertion into the ear canal of a user. 
       FIGS. 12 and 13 , illustrate another embodiment of an earphone tip  300 , incorporating the adapter  100 , formed as a monolithic structure with the cushion  310 .  FIG. 12  shows a perspective view of the earphone tip  300 , while  FIG. 13  depicts a cross-section of the earphone tip  300  as viewed along line C-C in  FIG. 12 . 
     Generally, the adapter  100  may be similar in structure and properties to that described above, with the inclusion of the cushion  310  circumferentially surrounding the adapter  100 . The material of the earphone tip  300 , and thus the cushion  310 , may be any desired soft, pliable polymeric material, such as a silicone material, including silicone based materials, which may be inserted into the ear canal of a user and closely conform to the surface of the ear canal. As can be seen best in  FIG. 13 , the cushion  310  may be secured to and extend from the adapter  100  at the distal end of the adapter  100  proximate the distal end  303  of the earphone tip  300 , and may generally curve outward and proximally therefrom, toward the proximal end of the adapter  100  and the proximal end  302  of the earphone tip  300 . In some embodiments, the bottom edge  321  (e.g., circumferential edge) of the cushion  310  may terminate in line with the proximal end of the adapter  100 . However, in other embodiments, the bottom edge  321  may terminate proximal of or distal of the proximal end of the adapter  100 . 
     Those skilled in the art will recognize that the present disclosure may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present disclosure as described in the appended claims.