Abstract:
A hearing aid instrument of the in-the-ear type (and preferably CIC) provides a receptacle with electronic hearing aid components mounted thereto. The receptacle has a cavity for holding electronic components (eg. battery, microphone, amplifier). A soft polymeric body is preliminarily formed by encapsulating a plurality of the electronic hearing aid component shaped inserts. The body is soft and is shaped to conform to the ear canal of the user. After forming, the insert is removed to provide an insert cavity that can carry electronic components. The soft polymeric body and encapsulated electronic hearing aid components define a soft structure compliant to the ear canal during use and that is substantially solid and free of void spaces between at least some of the components and the ear canal. This combination of soft compliant structure and encapsulated electronic hearing aid components addresses problems of peripheral leakage, poor fit, pivotal displacement that occurs with jaw motion and internal cross talk of components housed in prior art hollow type hearing aids.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part application of co-pending U.S. patent application Ser. Nos. 09/181,539, 09/181,540, 09/181,541, 09/181,842, 09/181,843, 09/181,844 now U.S. Pat. No. 6,228,020 and 09/181,845, all filed Oct. 28, 1998, which are continuations-in-part of application Ser. No. 09/084,864, filed May 26, 1998 now U.S. Pat. No. 6,022,311; all incorporated herein by reference. 
     Not applicable 
     This application claims the benefit of provisional application Ser. No. 06,068,035, filed Dec. 18, 1997. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     REFERENCE TO A “MICROFICHE APPENDIX” 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to hearing aids and more particularly to an improved hearing aid, its method of manufacture and an improved method of compensating for hearing loss. More particularly, the present invention provides an improved method and apparatus for compensating for hearing loss that uses a construction combining a mounting receptacle (for example, a receptacle or modular face plate or semi-modular face plate) with a soft polymeric body that is joined to the mounting member and which encapsulates some of the electronic hearing aid components of the apparatus, the soft polymeric body being sized and shaped to conform to the user&#39;s ear canal during use. It may be possible to use a soft polymeric material as the receptacle or face plate. 
     2. General Background of the Invention 
     The hearing industry has realized major strides in the development of high-fidelity, high-performance products, the most recent of which is digital signal processing technology. Hearing care professionals expected those advancements to solve the shortcomings of traditional amplification, and to push the market forward. Those expectations have not been fully realized. While these developments have solved many of the problems associated with traditional electronic design and steadily gained market share, they have not fostered overall market growth. 
     The issues of early acoustic feedback, less than optimum fidelity and intermodulation of the frequency response cannot be completely resolved by electronic manipulation of the signal by either analog or digital means. 
     Historically, custom-molded ear worn hearing instruments have been limited to an “acrylic pour” process as the means of the construction. With the advent of miniaturization and technological advancement of computer chip programming, the ear-worn instruments have become smaller and are positioned into the bony portion of the ear canal, commonly referred to as “deep insertion technology”. 
     Developments outside the hearing industry have culminated in a new level of micro-miniaturization of electronic components for industry applications. Consequently, advanced signal processing can be housed in less space than was required for traditional electro-acoustic components. 
     With the development of programmable hearing aids, using either analog or digital signal processing, custom electronic design has shifted from the manufacturing level to the clinical level. The clinician can now customize the electro-acoustic response via software. It is no longer necessary for the device to be returned to the manufacturer for hardware changes to arrive at the desired electro-acoustic response. However, it is still often necessary to return the device for shell modifications. 
     In direct contrast to electronic advances within the industry, little or no advancement has been realized in custom prosthetic design. Since the late 1960&#39;s, when the custom in-the-ear hearing aid was developed, materials and construction techniques remained virtually unchanged. These materials and techniques were adopted from the dental industry, whereby the customized housing-commonly called a “shell” was constructed using acrylic of 90 point Durometer Hardness Shore D. This construction process provided the structure and the strength of material necessary to protect the electronics. 
     At the time the acrylic shell was developed, hearing instruments were worn in the relatively forgiving cartilaginous portion of the ear canal. Micro-miniaturization of electronic components, combined with increased consumer demand for a cosmetically acceptable device, has shifted the placement of the hearing aid toward the bony portion of the ear canal. 
     The bony portion of the canal is extremely sensitive and intolerant of an acrylic shell when that shell is over sized due to standard waxing procedures or is in contact with the canal wall beyond the second anatomical bend. Rigid acrylic that does not compress must pivot in reaction to jaw or head movement, thereby changing the direction of the receiver yielding a distorted acoustic response. In addition, the pivot action causes displacement of the device resulting in unwanted acoustic feedback. This problem has necessitated countless shell modifications, thereby compromising the precision approach of the original dental technology. Many such devices require some modification by the manufacturer. Most manufacturers can expect a high percentage of returns for modification or repair within the first year. Consequently, CIC (completely in canal) shell design has been reduced to more of a craft than a science. Although the recent introduction of the ultra-violet curing process has produced a stronger, thinner shell, the overall Shore Hardness remained unchanged. 
     The current trend for custom hearing aid placement is to position the instrument toward the bony portion of the ear canal. The ear canal can be defined as the area extending from the concha to the tympanic membrane. It is important to note that the structure of this canal consists of elastic cartilage laterally, and porous bone medially. The cartilaginous portion constitutes the outer one third of the ear canal. The medial two-thirds of the ear canal is osseous or bony. The skin of the osseous canal, measuring only about 0.2 mm in thickness, is much thinner than that of the cartilaginous canal, which is 0.5 to 1 mm in thickness. The difference in thickness directly corresponds to the presence of apocrine (ceruminous) and sebaceous glands found only in the fibrocartilaginous area of the canal. Thus, this thin-skinned thinly-lined area of the bony canal is extremely sensitive to any hard foreign body, such as an acrylic hearing instrument. 
     Exacerbating the issue of placement of a hard foreign body into the osseous area of the ear canal is the ear canal&#39;s dynamic nature. It is geometrically altered by temporomandibular joint action and by changes in head position. This causes elliptical elongation (widening) of the ear canal. These alterations in canal shape vary widely from person to person. Canal motion makes it very difficult to achieve a comfortable, true acoustic seal with hard acrylic material. When the instrument is displaced by mandibular motion, a leakage or “slit leak” creates an open loop between the receiver and the microphone and relates directly to an electro-acoustic distortion commonly known as feedback. Peripheral acoustic leakage is a complex resonator made up of many transient resonant cavities. These cavities are transient because they change with jaw motion as a function of time, resulting in impedance changes in the ear canal. These transients compromise the electro-acoustic performance. 
     The properties of hard acrylic have limitations that require modification to the hard shell exterior to accommodate anatomical variants and the dynamic nature of the ear canal. The shell must be buffed and polished until comfort is acceptable. The peripheral acoustic leakage caused by these modifications results in acoustic feedback before sufficient amplification can be attained. 
     Hollow shells used in today&#39;s hearing aid designs create internal or mechanical feedback pathways unique to each device. The resulting feedback requires electronic modifications to “tweak” the product to a compromised performance or a “pseudo-perfection”. With the industry&#39;s efforts to facilitate the fine-tuning of hearing instruments for desired acoustic performance, programmable devices were developed. The intent was to reduce the degree of compromise, but by their improved frequency spectrum the incidence of feedback was heightened. As a result, the industry still falls well short of an audiological optimum. 
     A few manufacturers have attempted all-soft, hollow shells as alternatives to acrylic, hollow shells. Unfortunately, soft vinyl materials shrink, discolor, and harden after a relatively short period of wear. Polyurethane has proven to provide a better acoustic seal than polyvinyl, but has an even shorter wear life (approximately three months). Silicones have a long wear life but are difficult to bond with plastics such as acrylic, a necessary process for the construction of custom hearing instruments. To date, acrylic has proven to be the only material with long term structural integrity. The fact remains, however, that the entire ear is a dynamic acoustic environment and is ill-served by a rigid material such as acrylic. Also, the acrylic hearing aids typically need to be returned to the manufacturer for major shell modifications. 
     The following references are all incorporated herein by reference: 
     U.S. Pat. Nos.: 4,051,330; 4,375,016; 4,607,720; 4,716,985; 4,811,402; 4,870,688; 4,880,076; 4,937,876; 5,002,151; 5,068,902; 5,185,802; 5,201,007; 5,259,032; 5,530,763; 5,430,801; 5,500,902; and 5,659,621. 
     Also of interest and incorporated herein by reference are published Japanese patent application no. JA61-238198, the articles from December 1997 Journal of American Academy of Audiology, and Staab, Wayne J. and Barry Finlay, “A fitting rationale for deep fitting canal hearing instruments”, Hearing Instruments, Vol. 42, No. 1, 1991, pp. 7-10, 48. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a method of constructing a hearing aid and a soft hearing instrument that is solid (i.e. eliminates void spaces). This instrument includes a soft body portion that is truly soft, comprising an elastomer of about 3 to 55 Durometer Shore A and preferably 10-35 Durometer Shore A. This product is unique in that it is solid, with the electronic components actually encapsulated or embedded within the soft fill material. The fill material can be a Dow Corning® MDX-4- 4210  silicone or a silicone polymer distributed by Factor II, Inc. of Lakeside, Ariz., designated as product name 588A, 588B, 588V. 
     The present invention provides a method that can replace traditional acrylic shell construction. Unlike the shell construction process, the ear impression is not modified, built up, or waxed. With the elimination of these steps, a more faithful reproduction of the ear impression is accomplished. With the present invention, the manufacturer should be able to produce a hearing aid body which will not need to be returned as frequently for modification as with present hard acrylic hearing aid bodies. 
     The apparatus of the present invention is virtually impervious to the discoloration, cracking, and hardening experienced with polyvinyls and polyurethanes. 
     The hearing aid of the present invention provides a greater range of gain before feedback occurs. 
     The outer surface of the body of the present invention is preferably non-absorbent and virtually impervious to cerumen. 
     As used herein, “in-the-ear hearing aids” includes all hearing aids which have all of the electronics positioned in the ear, and thus includes hearing aid styles ranging from full concha to CIC (completely in the canal) hearing aid styles. 
     The preferred embodiment of the present invention shown in the drawings is a CIC hearing aid style. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
     FIG. 1 is a fragmentary, perspective view of the preferred embodiment of the apparatus of the present invention showing the mounting member portion thereof; 
     FIG. 2 is an elevational view of the insert portion of the preferred embodiment of the apparatus of the present invention; 
     FIG. 3 is an elevational side view of the insert portion of FIG. 2, taken along lines  3 — 3  of FIG. 2; 
     FIG. 4 is a fragmentary, perspective view of a portion of the insert in FIGS. 2 and 3; 
     FIG. 5 is a fragmentary, perspective view illustrating a portion of the insert of FIGS. 2 and 3; 
     FIG. 6 is a fragmentary, elevational view of the preferred embodiment of the apparatus of the present invention illustrating the mounting member and insert portions thereof; 
     FIGS. 7 and 8 are schematic views illustrating the method of the present invention; 
     FIGS. 9 and 10 are additional schematic, perspective views illustrating the method of the present invention; 
     FIGS. 11 and 12 are perspective views illustrating the final method steps of the method of the present invention including the assembly of electronic components to the soft elastomer body; 
     FIG. 13 is a perspective, exploded view of a second embodiment of the apparatus of the present invention; 
     FIG. 14 is a perspective view of the second embodiment of the apparatus of the present invention shown prior to the addition of liquid polymeric or elastomeric material to the cavity; 
     FIGS. 15-17 are perspective, schematic views illustrating the method of the present invention; 
     FIG. 17 is a perspective view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 18 is a fragmentary perspective view of a third embodiment of the apparatus of the present invention showing the mounting plate portion of the mounting member; 
     FIG. 19 is a perspective, fragmentary view of the third embodiment of the apparatus of the present invention illustrating one of the insert portion thereof; 
     FIGS. 20-20A are fragmentary perspective views of the third embodiment of the apparatus of the present invention showing the receptacle portion of the mounting member; 
     FIGS. 21-21A are partial, sectional, fragmentary views of the receptacle of FIG. 20; 
     FIG. 22 is a fragmentary, perspective view of the third embodiment of the apparatus of the present invention illustrative the mounting member including mounting plate and receptacle portions thereof and the insert portion thereof; 
     FIG. 23 is a fragmentary, perspective view of the third embodiment of the apparatus of the present invention illustrating the mounting member and insert portions thereof; 
     FIG. 24 is a fragmentary, perspective. exploded view of the third embodiment of the apparatus of the present invention illustrating the mounting member and insert portions thereof; 
     FIG. 25 is a side elevational view of the third embodiment of the apparatus of the present invention illustrating the method step of attaching the shell having a mold cavity to the mounting member and insert portions; 
     FIGS. 26 and 27 are perspective views illustrating method steps of the present invention including the filling of the mold cavity with elastomeric material to encapsulate the inserts and support the mounting members; 
     FIG. 28 is a perspective view of the third embodiment of the apparatus of the present invention illustrating the step of removing the shell from the soft polymeric bodies and the removal of the insert portions; 
     FIG. 29 is a perspective view of the method of constructing the third embodiment of the apparatus of the present invention showing the step of inserting the electronic hearing aid components into the soft polymeric body and mounting members; and 
     FIG. 30 is a perspective view of the third embodiment of the apparatus of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In FIGS. 1-12, there can be seen a method for constructing a hearing aid apparatus that is culminated in the addition of electronic components to the hearing aid apparatus as shown in FIGS. 11 and 12. FIG. 12 shows the completed hearing aid apparatus designated generally by the numeral  10 . 
     Hearing aid apparatus  10  is constructed with a beginning modular face plate  11  having a surface  12  and an opposing surface  13 . A plurality of stacking pins  14  can be provided at the periphery  16  of modular face plate  11 . Pins  14  enable shipments of several stacked modular face plates  11  with electronic components being placed therebetween. 
     A central opening  15  receives insert  19  during construction using the method of the present invention. The modular face plate  11  also becomes a part of the apparatus  10  of the present invention after construction is completed wherein the central opening  15  receives an electronic component carrying receptacle  18 . Modular face plate  11  has an opening  17  that receives an end portion of a vent tube as will be described more fully hereinafter. 
     The combination of modular face plate  11  and insert  19  are used to form a soft elastomeric or polymeric (eg. silicone) body  50  that will carry electronic hearing aid components to define a hearing aid electronics package during use. The insert  19  is best seen in FIGS. 2-5. The insert  19  and face plate  11  are used to construct soft elastomeric or polymeric body  50  as shown in FIGS. 6-10. 
     In FIGS. 2-5, insert  19  includes an insert body  20  having a curved surface  21 , a pair of opposed semi-circular flat surfaces  22 ,  23 , and flat surface  24 . Insert body  20  includes a cylindrical bore  25  that enables insert body  20  to be mounted on elongated, coated (eg. Teflon®) wire  27 . Insert body  20  also provides an extraction handle  26  that aids in its removal from soft polymeric body  50  after molding is complete and the soft elastomeric body has set. 
     In FIGS. 2-4, insert  19  also includes a receiver replica insert portion  28  having open ended bore  29 . The open ended bore  29  enables the receiver replica insert  28  to be mounted on coated wire  27 , as shown in FIGS. 2 and 3. 
     Each of the insert portions  20  and  28  can be adjustably, slidably mounted upon coated (eg. Teflon®) wire  27 , as indicated schematically by the arrows  30 ,  31 , in FIG.  2 . This feature enables a desired spacing between insert  20  and insert  28  to be achieved prior to construction of the soft polymeric body  50 . It should be understood that the insert members  20 ,  28  can be of different size and configuration. The insert  28  is typically a receiver replica insert that can be configured to duplicate the size and shape of any number of commercially available receivers or custom receivers. Similarly, the insert  20  is an insert that is of the size and shape of a receptacle  18  that will carry a number of electronic hearing aid components such as, for example, a battery, microphone, amplifier, etc. 
     Insert body  20  can be provided with a plurality of tabs  32  that fit sockets  33  next to central opening  15  as shown in FIGS. 1 and 5. Tabs  32  enable the insert body  20  to form a snap fit with modular face plate  11  at sockets  33  prior to the formation of soft polymeric body  50  using injected liquid elastomer (eg. Silicon). FIGS. 4 and 6 illustrate the attachment of insert  19  to modular face plate  11 . 
     In FIG. 7, mold  36  is shown being attached to modular face plate  11  as indicated by arrows  40 . In FIG. 7, vent tube replica insert  35  has been added to face plate  11  at opening  17 . In FIG. 8, mold  36  has been attached to modular face plate  11  using a bonding material. The construction of mold  36  and its attachment to a mounting member such as modular face plate  11  is shown and described in more detail in prior co-pending patent application Ser. No. 09/181,540, filed Oct. 28, 1998, which is hereby incorporated herein by reference. 
     In FIGS. 7 and 8, mold  36  has an outer surface  37 , a wall  38 , and a cavity  39 . A plurality of ports  41 - 45  are provided through the wall  38  as shown in FIGS. 7 and 8. In FIGS. 9 and 10, syringe  46  is shown adding elastomeric liquid material  47  through needle  48  into cavity  39 , as indicated by arrow  49  in FIG.  9 . The addition of elastomer  47  to cavity  39  encapsulates insert  19  and vent tube replica insert  35 . 
     After the elastomer  47  is allowed to set, the insert  19  and vent tube replica insert  35  can be removed as indicated in FIG.  10 . The insert  19  and vent tube replica insert  35  are shown gripped by a technician&#39;s finger  55  and thumb  56  and removed as indicated by arrow  54  from soft polymeric body  50  and mold  36 . By removing the inserts  19 ,  35 , a vent tube cavity  52  and an electronics cavity  53  are provided in soft polymeric body  50 . An electronics package of a number of electronic components can then be added to cavities  52 ,  53 . 
     In FIGS. 11 and 12, additional method steps of the present invention are shown. In FIG. 11, the soft polymeric body  50  is shown having an outer surface  51  after removal of mold  36  and after a trimming of modular face plate  11 . The modular face plate  11  is trimmed so that it exactly fits the outside contour of outer surface  51  of soft polymeric body  50  as shown in FIGS. 11 and 12. 
     In FIG. 11, the cavities  52 ,  53  that remain after removal of the inserts  19 ,  35  are replaced with electronic hearing aid components that enable the hearing aid  10  to function, including the components that are added into the cavities  52 ,  53  as indicated by arrows  57  in FIG.  11 . The electronic components that occupy cavities  52 ,  53  include eg. battery  59 , battery door  58 , amplifier  60 , microphone  61 , wire harness  63 , receiver  64 , receiver sound tube  65 , and locking tabs  62  that interlock with sockets  33  of modular face plate  11 . 
     The completed hearing aid apparatus  10  as shown in FIG. 12 with all of the electronic components in position, occupying the two cavities  52 ,  53 . A vent tube  66  is a tube that extends the full length of soft polymeric body  50 , forming a connection with opening  17  in modular face plate  11 . 
     In FIGS. 13-17, a second embodiment of the apparatus of the present invention is shown, designated generally by the numeral  70 . Hearing aid apparatus  70  is constructed using an alternate method. In FIGS. 13 and 14, the hearing aid apparatus  70  begins with mold  71  having an outer surface  72 , a wall  73  and a cavity  74 . A number of ports  75  are formed through wall  73 . A receptacle  76  that will carry electronic hearing aid components is attached to the mold wall  73  using a plurality of radially extending struts  80  as shown in FIGS. 13 and 14. 
     The receptacle  76  includes a pair of flat walls  78 ,  79  and a curved wall  77 . This construction provides a cavity  81  for holding a number of electronic hearing aid components. Opening  95  in receptacle  76  enables a wiring harness  84  to pass through cavity  81  and into mold cavity  74  as shown in FIGS. 13 and 14. The components that extend through opening  95  and are external to cavity  81  of receptacle  76  include a portion of wiring harness  84 , receiver  82 , and receiver sound tube  83 . Opening  96  in curved wall  77  of receptacle  76  enables vent tube  86  to pass through receptacle  76  curved wall  77  so that it can communicate with cavity  81 . 
     The components that are contained with cavity  81  of receptacle  76  include battery  90 , battery door  89 , amplifier  91 , microphone  92 , and locking tabs  93  that form a connection with sockets  97  that are on the flat peripheral surface  98  of receptacle  76 . In FIG. 13, the combination of the electronic components  82 ,  83 ,  84 ,  86 ,  89 ,  90 ,  91 ,  92  are attached to mold  71  in a temporary fashion using the radially extending struts as shown in FIGS. 13 and 14 and as indicated schematically by the arrow  85  in FIG.  13 . 
     In FIG. 15, syringe  47  can be used to inject liquid polymeric or elastomeric material, such as silicone, through needle  48  into cavity  74  of mold  71 . In this fashion, the cavity  74  is filled with soft polymeric or elastomeric material and encapsulates the electronic components that are below openings  95 ,  96 . Additionally, the material injected through needle  48  surrounds receptacle  76 , closely conforming to its curved wall  77  and flat walls  78 ,  79 . 
     The interior cavity  81  of receptacle  76  is not filled with polymeric material so that the cavity  81  can be occupied by some of the electronic hearing aid components. This construction enables replacement of the electronic hearing aid components that are contained within the cavity  81  of receptacle  76  without intrusion into the soft polymeric body  94  that is formed when the elastomeric or polymeric material in  47  injected with syringe  46  is allowed to set. 
     In FIG. 16, the radially extending struts  80  have been removed as indicated by arrows  87 . Arrow  88  indicates the addition of electronic hearing aid components to the cavity  81 , namely battery  90 , battery door  89 , amplifier  91 , microphone  92  and locking tabs  93 . The completed hearing aid apparatus  70  is shown in FIG.  17 . 
     FIGS. 18-30 show a third embodiment of the apparatus of the present invention, designated generally by the numeral  100  in FIG.  30 . In FIGS. 18-27, there can be seen a mounting assembly that includes a mounting plate  99  and receptacle  112  (See FIGS.  20 - 21 ). An alternate receptacle  112 A is shown in FIGS. 20A and 21A. The mounting plate  99  and receptacle  112  are positioned close to each other as shown in FIGS. 24-30 upon assembly. Mounting plate  99  has a central opening  101  and a periphery  102 . The mounting plate  99  can be generally flat, providing opposed flat surfaces  103 ,  104 . Receptacle  112  defines a mounting assembly with mounting plate  99  that can receive an insert such as members  27  and  28  that were described above with respect to the embodiment of FIGS. 1-12. 
     Insert  105  is similar to the insert of the embodiment of FIGS. 1-12, the difference being removal of tabs  32  (see FIG.  5 ). The embodiment of FIGS. 18-30 uses a receptacle  115  that is closely positioned to the plate  99  as shown in FIGS. 24-30. Insert  105  thus provides surfaces  21 ,  22 ,  23  as the insert shown in FIG.  5 . The tabs  32  have been removed. The insert  105  has a smooth, flat undersurface  106 . Curved surface  21  fits a cavity  119  of receptacle  115  during construction using the method of the present invention. 
     In FIGS. 19-21, receptacle  112  is comprised of a pair of flanges  113 ,  114  and an external curved wall  115 . An opening  116  is provided in curved wall  115 . The flanges  13 ,  14  provide arc shaped edges  117  and straight edge portions  118 ,  119 . Arrows  120  in FIG. 22 illustrate the assembly of insert  105 , mounting plate  99 , and receptacle  112 . 
     In FIGS. 20A and 21A, an alternate construction for the receptacle is shown as receptacle  124 . Receptacle  124  has spaced apart semicircular walls  125 ,  126  that can be generally parallel to each other. External curved wall  127  spans between walls  125 ,  126 . Opening  129  in receptacle  129  allows a wiring harness to pass therethrough. A cavity  128  is formed by walls  125 ,  126 ,  127 . Each wall  125 ,  126  has a straight edge portion indicated as  130 ,  131  respectively in FIGS. 20A,  20 B. Cavity  128  receives some electronic hearing aid components, similar to the cavity  122  of receptacle  112  (see FIGS.  29 - 30 ). 
     In FIG. 23, the insert  105 , mounting plate  99 , and receptacle plate  112  have been assembled in operating position before molding using shell  36 . FIGS. 24-27 illustrate the molding steps of forming a soft polymeric body  108  about inserts  105 ,  35 . Mounting plate  99  has an opening  121  that receives vent tube insert  35 . Insert  105  has a cylindrically shaped open ended channel  25  that receives coated wire  27 . Arrow  123  in FIG. 24 illustrates the assembly of coated wire insert  27  to cylindrically shaped opening  25  of insert  105 . FIG. 25 shows the completed assembly of mounting plate  99 , receptacle  112 , insert  105 , and insert  35 . In FIG. 25, shell  35  is shown being lowered in the direction of arrows  107  until it fits over the inserts  105 ,  35 , and registers against the flat surface  103  of mounting plate  99  as shown in FIGS. 26 and 27. As with the embodiment of FIGS. 1-12, the inserts  105 ,  35  extend through openings in the shell  36  so that when the inserts  35 ,  105  are removed after the soft polymeric body  108  is formed, they will leave behind recesses to be occupied by electronic hearing aid components. 
     In FIG. 27, needle  48  is shown injecting elastomeric material (eg. silicone) as indicated by the arrows  49  to the mold cavity formed inside of shell  36 . After the elastomeric material  47  in FIG. 27 is allowed to set, shell  36  is removed as shown by arrows  124  in FIG. 28. A user then removes the inserts  35 ,  105  using thumb and forefinger  55 ,  56  as shown in FIG.  28 . The arrow  54  in FIG. 28 indicates schematically the removal of the inserts to leave behind cavities  109 ,  110 . In FIG. 29, a user or technician uses his or her thumb and finger  55 ,  56  to pull an electronic hearing aid package into the cavities  109 ,  110  in soft body  108 . As with the embodiment of FIGS. 1-12, these components can include, for example battery door  58 , battery  59 , amplifier  60 , microphone  61 , wire harness  63 , receiver  64 , receiver sound tube  65 , and vent tube  66 . 
     In the embodiment of FIGS. 13-30, a technician can sever the wiring harness  84  after the electronic components that are contained within cavity  81  have been lifted upwardly to the position of FIG. 16, enabling those components to be serviced, replaced, etc. If the components below openings  95 ,  96  need to be serviced, those can be removed by either cutting the soft polymeric body  94  or by carefully removing them through expansion of the cavity in which they are contained. 
     Parts List 
     The following is a list of suitable parts and materials for the various elements of the preferred embodiment of the present invention. 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 10 
                 hearing aid apparatus 
               
               
                 11 
                 modular face plate 
               
               
                 12 
                 surface 
               
               
                 13 
                 surface 
               
               
                 14 
                 stacking pin 
               
               
                 15 
                 central opening 
               
               
                 16 
                 periphery 
               
               
                 17 
                 vent tube opening 
               
               
                 18 
                 receptacle 
               
               
                 19 
                 insert 
               
               
                 20 
                 insert body 
               
               
                 21 
                 curved surface 
               
               
                 22 
                 flat surface 
               
               
                 23 
                 flat surface 
               
               
                 24 
                 flat surface 
               
               
                 25 
                 cylindrical bore 
               
               
                 26 
                 extraction handle 
               
               
                 27 
                 elongated coated wire 
               
               
                 28 
                 receiver replica insert 
               
               
                 29 
                 open ended bore 
               
               
                 30 
                 arrow 
               
               
                 31 
                 arrow 
               
               
                 32 
                 tab 
               
               
                 33 
                 socket 
               
               
                 34 
                 arrow 
               
               
                 35 
                 vent tube replica insert 
               
               
                 36 
                 mold 
               
               
                 37 
                 outer surface 
               
               
                 38 
                 wall 
               
               
                 39 
                 cavity 
               
               
                 40 
                 arrow 
               
               
                 41 
                 port 
               
               
                 42 
                 port 
               
               
                 43 
                 port 
               
               
                 44 
                 port 
               
               
                 45 
                 port 
               
               
                 46 
                 syringe 
               
               
                 47 
                 elastomer 
               
               
                 48 
                 needle 
               
               
                 49 
                 arrow 
               
               
                 50 
                 soft elastomeric body 
               
               
                 51 
                 outer surface 
               
               
                 52 
                 vent tube cavity 
               
               
                 53 
                 electronics cavity 
               
               
                 54 
                 arrow 
               
               
                 55 
                 technicians finger 
               
               
                 56 
                 technician&#39;s thumb 
               
               
                 57 
                 arrow 
               
               
                 58 
                 door 
               
               
                 59 
                 battery 
               
               
                 60 
                 amplifier 
               
               
                 61 
                 microphone 
               
               
                 62 
                 locking tabs 
               
               
                 63 
                 wire harness 
               
               
                 64 
                 receiver 
               
               
                 65 
                 receiver sound tube 
               
               
                 66 
                 vent tube 
               
               
                 67 
                   
               
               
                 68 
                   
               
               
                 69 
                   
               
               
                 70 
                 hearing aid apparatus 
               
               
                 71 
                 mold 
               
               
                 72 
                 outer surface 
               
               
                 73 
                 wall 
               
               
                 74 
                 cavity 
               
               
                 75 
                 port 
               
               
                 76 
                 receptacle 
               
               
                 77 
                 curved wall 
               
               
                 78 
                 flat wall 
               
               
                 79 
                 flat wall 
               
               
                 80 
                 radially extending strut 
               
               
                 81 
                 cavity 
               
               
                 82 
                 receiver 
               
               
                 83 
                 receiver sound tube 
               
               
                 84 
                 wire harness 
               
               
                 85 
                 arrow 
               
               
                 86 
                 vent tube 
               
               
                 87 
                 arrow 
               
               
                 88 
                 arrow 
               
               
                 89 
                 door 
               
               
                 90 
                 battery 
               
               
                 91 
                 amplifier 
               
               
                 92 
                 microphone 
               
               
                 93 
                 locking tabs 
               
               
                 94 
                 soft polymeric body 
               
               
                 95 
                 opening 
               
               
                 96 
                 opening 
               
               
                 97 
                 socket 
               
               
                 98 
                 flat peripheral surface 
               
               
                 99 
                 mounting plate 
               
               
                 100 
                 hearing aid apparatus 
               
               
                 101 
                 opening 
               
               
                 102 
                 periphery 
               
               
                 103 
                 surface 
               
               
                 104 
                 surface 
               
               
                 105 
                 insert 
               
               
                 106 
                 surface 
               
               
                 107 
                 arrow 
               
               
                 108 
                 soft elastomeric body 
               
               
                 109 
                 vent tube cavity 
               
               
                 110 
                 electronics cavity 
               
               
                 111 
                 trimmed periphery 
               
               
                 112 
                 receptacle 
               
               
                 113 
                 flange 
               
               
                 114 
                 flange 
               
               
                 115 
                 external wall 
               
               
                 116 
                 opening 
               
               
                 117 
                 arc shaped edge 
               
               
                 118 
                 straight edge 
               
               
                 119 
                 straight edge 
               
               
                 120 
                 arrows 
               
               
                 122 
                 cavity 
               
               
                 123 
                 arrow 
               
               
                 124 
                 receptacle 
               
               
                 125 
                 semicircular wall 
               
               
                 126 
                 semicircular wall 
               
               
                 127 
                 external wall 
               
               
                 128 
                 cavity 
               
               
                 129 
                 opening 
               
               
                 130 
                 straight edge 
               
               
                 131 
                 straight edge 
               
               
                   
               
             
          
         
       
     
     The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.