Patent Publication Number: US-9432760-B2

Title: Conformable eartip

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE 
     This application is a continuation of U.S. patent application Ser. No. 14/475,928, entitled “Conformable Eartip,” filed on Sep. 3, 2014, which makes reference to, claims priority to, and claims benefit from U.S. Provisional Patent Application Ser. No. 61/873,690, entitled “Conformable Eartip,” filed on Sep. 4, 2013. The entire contents of each above-mentioned prior-filed application is hereby expressly incorporated herein by reference. 
    
    
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     [Not Applicable] 
     MICROFICHE/COPYRIGHT REFERENCE 
     [Not Applicable] 
     BACKGROUND OF THE INVENTION 
     The present invention relates to an eartip that conforms to the various shapes of human ear canals and provides an acoustic and pressure seal to the ear canal. More specifically, the present invention provides an eartip that seals to ear canals quicker, easier, and more comfortably than existing eartips. The conformable eartip provides a low coefficient of friction so that the eartip inserts into the ear canal without discomfort and allows for direct insertion into the ear canal without requiring preparatory compression of the foam. The conformable eartip creates a minimal amount of pressure against the ear canal when inserted, has the ability to significantly distort its shape to easily conform to non-circular ear canal shapes, conforms to bends in an ear canal, and provides a seal at varying depths within an ear canal. 
     There are three common categories of commercially available eartips, compressible foam, elastomeric, and custom earmolds. Compressible foam tips are nominally round foam cylinders that seal to the ear canal through compressibility of the foam. Compressible foam eartips are generally pre-formed by compressing the foam to reduce the outer diameter, allowing the tip to enter the ear canal before recovery of the foam to its relaxed diameter. As the foam expands in the ear canal it seals against the surface of the ear canal walls. Compressible foam eartips are often made of slow-recovery foam allowing for time between manually pre-compressing the foam and inserting it into the ear canal. A disadvantage of compressible foam eartips is that the eartips typically require the user to compress the foam prior to insertion into the ear canal. 
     Another common problem with compressible foam eartips is that the expansion of the foam in the ear canal can cause significant pressure against the ear canal wall. The excessive pressure against the ear canal wall may cause discomfort for a user of the eartip. Additionally, many existing compressible foam eartips do not conform to bends in an ear canal when attached to a sound tube of a hearing device. The inability of compressible foam eartips to conform to bends in an ear canal may prevent the eartips from providing a seal, particularly at deeper insertion depths. At shorter insertion depths, compressible foam eartips can be ineffective for excluding noise and can increase the amount of occlusion effect a user experiences when talking. A further disadvantage of existing compressible foam eartips is that a greater diameter of foam is typically needed to completely seal non-circular ear canals because the foam does not appreciably expand outward during recovery to its relaxed diameter. 
     Elastomer eartips are nominally round forms that are generally directly inserted into the ear canal without pre-compression. A common problem with elastomer eartips is that friction between the eartip and the ear canal wall can make the insertion of the eartip more difficult and less comfortable. A lubricant applied to the eartip can provide a reduction of friction but is seldom used because it can be messy and/or inconvenient. Additionally, existing elastomer eartips do not easily conform to the ear canal, which may cause significant pressure against the ear canal wall. The excessive pressure against the ear canal wall can cause discomfort for the user of the eartip. 
     Another disadvantage of existing elastomer eartips is that the eartips have difficulty sealing to the varying shapes of human ear canals. For example, many elastomer eartips may crease inward when inserted in non-circular ear canals thereby preventing a seal from forming between the eartip and the ear canal. Many existing elastomer eartips include thick and/or otherwise large core sections that inhibit the eartips ability to conform to bends in an ear canal. The inability of existing elastomer eartips to conform to bends in an ear canal may prevent a seal from forming between the eartips and the ear canal and/or can cause discomfort to a wearer because the ear canals may be forced to conform to the eartips. Also, elastomer eartips typically require deep insertion due to the nominal size of the eartips relative to the ear canal and the lack of conformability of the eartips. The ability to achieve a seal without deep insertion to the ear canal is particularly beneficial when the user is uncomfortable with inserting eartips into their ear canal, or for those where a deeper insertion is in itself uncomfortable. 
     Some elastomer eartips provide multiple sealing surfaces in incrementally increasing diameters, intended to allow the eartip to seal to a larger range of eartip diameters. Although multi-flange elastomer eartips may seal to a large variety of ear canal sizes, a significantly deeper insertion is typically needed for larger size ear canals and the insertion depth with smaller size ear canals may be limited. Another disadvantage of the multi-flange elastomer eartip style is a longer minimum length to accommodate the multiple sealing surfaces. 
     Custom earmolds are derived from a measurement or mold of the individual ear canal and are typically produced using silicone materials. Custom earmolds properly fit only the ear canal for which it was made, sealing to the ear canal by mating exactly with the ear canal shape. A common problem with custom earmolds is that friction between the material and the ear canal wall can make the insertion of the eartip more difficult and less comfortable. A lubricant applied to the eartip can provide a reduction of friction but is seldom used because it can be messy and/or inconvenient. Other problems with existing custom earmolds include the high cost of custom earmolds, the additional time needed for fitting and manufacturing the custom earmolds, and the inability to vary the insertion depth of the custom earmolds. 
     Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application. 
     SUMMARY OF THE INVENTION 
     Certain embodiments of the present technology provide conformable eartips, substantially as shown in and/or described in connection with at least one of the figures. 
     These and other advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING(S) 
         FIG. 1  depicts a top perspective view of an exemplary conformable eartip used in accordance with embodiments of the present technology. 
         FIG. 2  depicts a bottom perspective view of an exemplary conformable eartip used in accordance with embodiments of the present technology. 
         FIG. 3  depicts a cross-sectional side elevation view of an exemplary conformable eartip used in accordance with embodiments of the present technology. 
         FIG. 4A  depicts a top plan view of a relaxed state and a compressed state of an exemplary conformable eartip used in accordance with embodiments of the present technology. 
         FIG. 4B  depicts a cross-sectional side elevation view of an exemplary conformable eartip coupled to a sound tube used in accordance with embodiments of the present technology. 
         FIG. 5  depicts a cross-sectional side elevation view illustrating an exemplary angular compliance of an exemplary conformable eartip coupled to a sound tube used in accordance with embodiments of the present technology. 
         FIG. 6  depicts a cross-sectional side elevation view of an exemplary conformable eartip used in accordance with embodiments of the present technology. 
         FIG. 7  depicts a top perspective view of an exemplary conformable eartip used in accordance with embodiments of the present technology. 
         FIG. 8  depicts a bottom perspective view of an exemplary conformable eartip used in accordance with embodiments of the present technology. 
         FIG. 9  depicts a cross-sectional side elevation view of an exemplary conformable eartip coupled to a hearing device used in accordance with embodiments of the present technology. 
         FIG. 10  depicts a cross-sectional side elevation view of an exemplary elongated conformable eartip coupled to a sound tube used in accordance with embodiments of the present technology. 
         FIG. 11  depicts a bottom perspective view of an exemplary conformable eartip that is conforming by compressing and elongating as used in accordance with embodiments of the present technology. 
         FIG. 12  depicts a top perspective view of an exemplary conformable eartip that is conforming by compressing and elongating as used in accordance with embodiments of the present technology. 
         FIG. 13  depicts a cross-sectional side elevation view of an exemplary compressed conformable eartip coupled to a sound tube used in accordance with embodiments of the present technology. 
     
    
    
     The foregoing summary, as well as the following detailed description of embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, certain embodiments are shown in the drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S) 
     Embodiments of the present technology provide an eartip that conforms to the various shapes of human ear canals and provides an acoustic and pressure seal to the ear canal. The conformable eartip provides a low coefficient of friction so that the eartip inserts into the ear canal without discomfort and allows for direct insertion into the ear canal without requiring preparatory compression of the foam. The conformable eartip creates a minimal amount of pressure against the ear canal when inserted, has the ability to significantly distort its shape to easily conform to non-circular ear canal shapes, conforms to bends in an ear canal, and provides a seal at varying depths within an ear canal. 
     Various embodiments provide a conformable eartip  100  comprising a round flange  110  and a core  120 . The round flange comprises a sealing surface  115  for mating with walls of an ear canal. The round flange  110  extends from an insertion end  101  to an opposite end  102  of the conformable eartip  100 . The sealing surface  115  is tapered from the opposite end  102  toward the insertion end  101  of the conformable eartip  100 . The core  120  is joined to the round flange  110  at the insertion end  101  of the conformable eartip  100 . In various embodiments, the core  120  may extend from the insertion end  101  to a base  125  of the core  120  toward the opposite end  102  of the conformable eartip  100 . The amount of extension of the core  120  can vary in certain embodiments, as illustrated in  FIG. 4B  compared to  FIG. 9 , for example. The core  120  includes a channel  125  extending through the core  120  from the insertion end  101  of the conformable eartip  100  to the base  125  of the core  120 . In various embodiments, the conformable eartip  100  provides an elongation ratio, E, of at least 1.4 and/or a compression ratio, C, of at least 2.0. 
       FIG. 1  depicts a top perspective view of an exemplary conformable eartip  100  used in accordance with embodiments of the present technology.  FIG. 2  depicts a bottom perspective view of an exemplary conformable eartip  100  used in accordance with embodiments of the present technology.  FIG. 3  depicts a cross-sectional side elevation view of an exemplary conformable eartip  100  used in accordance with embodiments of the present technology. 
     Referring to  FIGS. 1-3 , there is shown an exemplary conformable eartip  100  comprising a flange  110  that is integrated with or fixably attached to a core  120 . In various embodiments, the conformable eartip  100  can be high-density closed-cell polyurethane foam, silicone or other elastomeric foam, open-cell foam that has a surface sealing coating, or any suitable foam material that provides an acoustic and pressure seal to an ear canal. In embodiments where a pressure seal is not needed, the conformable eartip  100  may be open-cell foam or any suitable foam material that provides an acoustic seal, for example. 
     The flange  110  can be generally round and may provide a sealing surface  115  for mating with walls of an ear canal. The rounded shape of the flange  110  can reduce the tendency of the flange  110  to crease inward, causing leakage, for example. The flange  110  can be formed by hollowing out a section  140  between the flange  110  and the core  120  to allow the flange  110  to freely compress and elongate for conforming to an ear canal of a wearer. The flange  110  can extend a distance from an insertion end of the eartip  100  and may be tapered at an angle for ease of insertion as discussed in more detail below, for example. In various embodiments, the thickness of the flange may be as much as 30% of the outer diameter of the eartip or thinner, for example. The thin flange wall increases the range of conformance of the eartip  100  and allows the eartip  100  to conform and seal to the ear canal without applying a significant pressure against the ear canal wall, providing a more comfortable fit. The thin flange wall in conjunction with the length of extension of the flange  110  from the core  120  (e.g., the hollowed-out section  140 ) enables the eartip  100  to compress and extend more completely than existing eartips. In various embodiments, the flange wall can have a substantially uniform thickness. 
     The core  120  may be generally round and can comprise a channel  130  extending through the core  120  from an insertion end  101  of the eartip  100  to a base  125  of the core  120 . In various embodiments, the channel  130  of the core  120  can receive a tube or stem  200 , as illustrated in  FIGS. 4B and 5 , for example. The tube or stem  200  can be affixed in the channel by an adhesive such as a room temperature vulcanizing (RTV) silicone rubber adhesive, other adhesive, solvent bonded, or insert molded, among other things. Alternatively, the eartip may be affixed directly to a hearing device, as illustrated in  FIG. 9 , for example. In various embodiments, the tube or stem  200  can attach to a hearing device, such as an audio player earphone, a communications earphone, a hearing aid, a hearing testing apparatus, an earplug, or any suitable hearing device. In certain embodiments, a wall of the core  120  can have a substantially uniform thickness and/or have substantially the same thickness as the wall of the flange  110 . 
       FIG. 4A  depicts a top plan view of a relaxed state and a compressed state of an exemplary conformable eartip  100  used in accordance with embodiments of the present technology. Referring to  FIG. 4A , the ability of an eartip  100  to conform to an ear canal can be determined by the ratio of the maximum outer diameter (D 2 ) of the sealing surface  115  of the flange  110  to the minimum width of the sealing surface  115  of the flange  110  under compression (Z 2 ), but without compression of the eartip material, for example. This minimum width is defined as the diameter of the sound tube  200 , plus 2 times the thickness of the core  120  wall, plus two times the thickness of the flange  110  wall. In other words, the compression ratio, C, equals D 2 /Z 2 . The compression ratio of an eartip  100  may indicate the narrowest dimension of an ear canal to which the eartip  100  comfortably fits, without causing significant pressure against the ear canal wall or distorting the ear canal, for example. The structure of the conformable eartip  100  provides thin walls of the flange  110  and a narrow core  120 , allowing the flange  110  to collapse completely to the core  120 , and resulting in a compression ratio of 2.0 or greater. The compression ratio of existing commercially available eartips measured ranged from 1.0 to 1.88. 
     The ability of an eartip  100  to seal to an ear canal can be determined based on the ability of the eartip  100  to elongate the sealing surface of the flange  110  to meet the profile of a typically elliptical ear canal. The elongation may be determined by a ratio of the maximum width of the sealing surface  115  of the flange  110  at full compression (Z 1 ) with the maximum nominal outer diameter (D 2 ) of the sealing surface  115  of the flange  110 . In other words, the elongation ratio, E, equals Z 1 /D 2 . The conformable eartip  100  provides a hollowed out section  140  between the flange  110  and the core  120  that allows the eartip  100  to freely elongate from its relaxed state. In various embodiments, the conformable eartip  100  provides an elongation ratio, E, of 1.4 or greater. The elongation ratio, E, of existing available eartips measured ranged from 1.0 to 1.2. 
       FIG. 4B  depicts a cross-sectional side elevation view of an exemplary conformable eartip  100  coupled to a sound tube  200  used in accordance with embodiments of the present technology.  FIG. 5  depicts a cross-sectional side elevation view illustrating an exemplary angular compliance, A 2 , of an exemplary conformable eartip  100  coupled to a sound tube  200  used in accordance with embodiments of the present technology. 
     Referring to  FIGS. 4B and 5 , the ability of an eartip to adapt to a bend in the ear canal may be determined by measuring the amount of deflection (A 2 ), with a given axial load at a stem or sound tube  200 , of the sealing surface  115  of the flange  110  with respect to the stem or sound tube  200 . The deflection (A 2 ) of the eartip  100  allows the sealing surface  115  of the flange  110  to mate with ear canal walls of a wearer in the same manner as it would without or before an ear canal bend. Human ear canals typically have a bend along the length of the canal. An eartip that is unable to accommodate a bend in the ear canal can have difficulty sealing properly unless it distorts the ear canal walls to meet the sealing surface of the tip. In various embodiments, the sealing surface  115  of the flange  110  deflects at a hinge point  150  at an ear canal insertion end  101  of the eartip  100  from a nominal angle to the sound tube  200  such that the eartip  100  may readily conform the shape of the sealing surface  115  to maintain a seal to the ear canal as it bends, as illustrated in  FIG. 5 , for example. Aspects of the present invention provide a conformable eartip with an angular compliance (A 2 ) of up to 45 degrees. For example, various embodiments provide a maximum angular compliance (A 2 ) between 20 and 45 degrees, or any range therebetween. Existing available eartips measured a maximum angular compliance (A 2 ) of less than 20 degrees. 
     Certain embodiments provide that an eartip  100  can seal to an ear canal of a wearer where the outer diameter, in either a nominal profile (D 2 ) or distorted to match the profile of the ear canal, is of sufficient size to at least match the diameter or effective diameter of the ear canal. The maximum outer diameter of the eartip sealing surface is, in common practice, not directly at the insertion end  101  of the eartip  100  but at some distance (D 3 ) behind the insertion end  101  of the eartip  100 . In various embodiments, the distance (D 3 ) can define a minimum insertion depth for sealing the eartip  100  in the ear canal, where shorter minimum insertions depths may provide a more versatile eartip. In certain embodiments, the distance (D 3 ) may not be less than the maximum eartip diameter (D 2 ) minus the minimum eartip diameter (D 1 ) over the effective taper angle (A 1 ) of the eartip  100 . 
     Referring to  FIG. 4B , the ease of which a particular eartip may be inserted into an ear canal may be defined by three aspects: the friction coefficient of the material, the need for pre-insertion activity, and the taper angle (A 1 ) of the sealing surface  115  of the flange  110 . Various embodiments provide that the eartip  100  is composed of materials that have a low friction coefficient, such as high-density closed-cell polyurethane foam, silicone or other elastomeric foam, open-cell foam, or the like. 
     Regarding pre-insertion activity, when additional steps are needed prior to inserting an eartip into an ear canal of a wearer, the additional steps can make the insertion process generally more difficult and/or complicated. For example, aligning an eartip to a particular orientation, adding lubricant to an eartip, and/or pre-forming the eartip by compressing the foam to reduce the outer diameter is generally more difficult and/or complicated than inserting an eartip without pre-insertion activity. Various embodiments provide that the eartip  100  is inserted into an ear canal of a wearer without performing pre-insertion activity. 
     The taper angle (A 1 ) of the sealing surface of the flange  110  defines a shape of the eartip  100  that impacts the ease of insertion of the eartip  100  into an ear canal of a wearer. The taper angle (A 1 ) of the sealing surface of the flange  110  can be determined by the following formula: 
               A   ⁢           ⁢   1     =       tan     -   1       ⁢       D   ⁢           ⁢   3       (         D   ⁢           ⁢   2     -     D   ⁢           ⁢   1       2     )               
where D 3  is the distance between the insertion end  101  of the eartip  100  and an opposite end  102  of the flange  110  (as illustrated in  FIG. 4B ), D 1  is the minimum eartip  100  diameter (as illustrated in  FIG. 4A ), and D 2  is the maximum eartip  100  diameter (as illustrated in  FIG. 4A ). In various embodiments, the minimum eartip diameter (D 1 ) can be the outer diameter of the core  120 , for example. Aspects of the present invention provide that a taper angle (A 1 ) of the sealing surface of the flange  110  is at least 45 degrees to enable conformability and less than 75 degrees so that the flange  110  taper is shallow enough to enable sealing at a short distance.
 
       FIG. 6  depicts a cross-sectional side elevation view of an exemplary conformable eartip used in accordance with embodiments of the present technology.  FIG. 7  depicts a top perspective view of an exemplary conformable eartip used in accordance with embodiments of the present technology.  FIG. 8  depicts a bottom perspective view of an exemplary conformable eartip used in accordance with embodiments of the present technology.  FIG. 9  depicts a cross-sectional side elevation view of an exemplary conformable eartip coupled to a hearing device used in accordance with embodiments of the present technology.  FIG. 10  depicts a cross-sectional side elevation view of an exemplary elongated conformable eartip coupled to a sound tube used in accordance with embodiments of the present technology.  FIG. 11  depicts a bottom perspective view of an exemplary conformable eartip that is conforming by compressing and elongating as used in accordance with embodiments of the present technology.  FIG. 12  depicts a top perspective view of an exemplary conformable eartip that is conforming by compressing and elongating as used in accordance with embodiments of the present technology.  FIG. 13  depicts a cross-sectional side elevation view of an exemplary compressed conformable eartip coupled to a sound tube used in accordance with embodiments of the present technology. 
     The conformable eartip  100  illustrated in  FIGS. 6-13  share various characteristics with the conformable eartip  100  illustrated in  FIGS. 1-5  as described above. 
     In a representative embodiment, a conformable eartip  100  is provided that comprises a round flange  110  and a core  120 . The round flange includes a sealing surface  115  for mating with walls of an ear canal. The round flange  110  extends from an insertion end  101  to an opposite end  102  of the conformable eartip  100 . The sealing surface  115  is tapered from the opposite end  102  toward the insertion end  101  of the conformable eartip  100 . The core  120  is joined to the round flange  110  at the insertion end  101  of the conformable eartip  100 . The core  120  extends from the insertion end  101  to a base  125  of the core  120  toward the opposite end  102  of the conformable eartip  100 . The core  120  includes a channel  125  extending through the core  120  from the insertion end  101  of the conformable eartip  100  to the base  125  of the core  120 . In various embodiments, the conformable eartip  100  provides an elongation ratio, E, of at least 1.4 and/or a compression ratio, C, of at least 2.0. 
     While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood that the invention is not limited thereto since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings.