Abstract:
A method and apparatus for a modular hearing aid for a user having a hearing canal, including a microphone connected to signal processing electronics and a power supply, a housing shaped for use in at least a portion of the hearing canal and including at least one opening and a microphone hood detachably connected to the opening in the housing, wherein the microphone hood includes one or more external ports linked to an internal port such that air may flow between the one or more external ports and the internal port. In various examples, a microphone housing is adapted to mount to the housing and to fit within the at least one access port, and to connect to the microphone, the signal processing electronics and the power supply. In one variant, the apparatus includes a receiver connected to the signal processing electronics, and a fastener as a unitary connector of the cover and microphone housing to the housing. Other variations are presented herein.

Description:
RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 10/824,775 filed Apr. 15, 2004, now U.S. Pat. No. 7,443,992 which is incorporated by reference and made a part hereof in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This disclosure relates generally to hearing aids and, more particularly, to a method and apparatus for a modular hearing aid. 
     BACKGROUND 
     One goal of hearing aids is to replicate natural hearing. To achieve this goal, hearing aids must satisfy multiple requirements. For example, hearing aids must be comfortable and discreet. Hearing aids must also improve hearing, and often times use high-tech electronics to achieve this. Finally, hearing aids should be affordable. Accordingly, a comfortable, small, affordable, and high-tech hearing aid which improves hearing is desired. 
     One way to improve comfort and function of a hearing aid is to custom fit components to the anatomy of the user. In some hearing aid examples, this can lower the potential for a feedback loop to form between the hearing aid speaker (the portion which produces sound for the user, also known as the hearing aid receiver) and the hearing aid microphone (the portion which gathers sound from the environment). Unfortunately, customizing components for each user is resource intensive, and increase costs. Therefore, it is desired to provide a hearing aid design which is customizable and affordable. 
     Hearing aid effectiveness can be further improved by customizing the sound processing function of the hearing aid to the hearing needs of the individual user. Often, hearing aid function can be customized using electronics, such as micro-computers, which gather sound with a microphone, change it in a way which is helpful to the user, and then broadcast it to the user using the speaker or receiver. Unfortunately, adding these features to a hearing aid can increase hearing aid size and cost. Therefore, it is desired to provide a hearing aid which is adapted to perform signal processing to improve hearing without sacrificing size or cost. 
     Thus, there is a need for a hearing aid design which increases customization options without reducing affordability, comfort, and without detracting from aesthetics or function. 
     SUMMARY 
     The above-mentioned problems and others not expressly discussed herein are addressed by the present subject matter and will be understood by reading and studying this specification. 
     The present subject matter includes a method and apparatus for a modular hearing aid for a user having a hearing canal, including a microphone connected to signal processing electronics and a power supply, a housing shaped for use in at least a portion of the hearing canal and including at least one opening and a microphone hood detachably connected to the opening in the housing, wherein the microphone hood includes one or more external ports linked to an internal port such that air may flow between the one or more external ports and the internal port. Further, the apparatus includes a receiver connected to the signal processing electronics, and a fastener as a unitary connector of the cover and microphone housing to the housing. 
     The present subject matter also includes a method of assembling a hearing apparatus for a user having a hearing canal. The method includes making a housing shaped for use at least partially inside the hearing canal, the housing including an access port and an opening. The method also includes assembling a microphone, a receiver, and signal processing electronics to a microphone housing. Additionally, the method includes inserting the microphone housing, microphone, receiver, and signal processing electronics into the housing through the access port. In various embodiments, the method also includes placing a cover to at least partially close the access port, and it further includes, in some embodiments, using a fastener as a unitary connector of the cover and the microphone housing to the housing. 
     The presently described subject matter also includes a hearing apparatus for a user having a hearing canal which includes a housing adapted to fit within at least a portion of the hearing canal, the housing having at least one access port and a mount for a pin. The apparatus also includes a cover adapted for at least partially covering the at least one access port, and including a mount for a pin. Additionally, the apparatus includes signal processing electronics connected to a microphone and a power supply, the signal processing electronics adapted to fit within the at least one access port. In various embodiments, the apparatus includes a microphone housing, adapted to mount to the housing and the access port, the microphone housing connected to the microphone, the signal processing electronics and the power supply, and including a mount for a pin. Various embodiments also include a receiver connected to the signal processing electronics, and a hinge pin as a unitary connector of the housing mount, the cover mount, and the microphone housing mount. 
     This Summary is an overview of some of the teachings of the present application and not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description and appended claims. Other aspects will be apparent to persons skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, each of which are not to be taken in a limiting sense. The scope of the present invention is defined by the appended claims and their legal equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. 
         FIG. 1  illustrates a hearing aid according to one embodiment of the present subject matter. 
         FIG. 2  illustrates a faceplate which has not been mounted to a shell, in one embodiment of the present subject matter. 
         FIG. 3  illustrates a hearing aid using a cover, and shows the cover in an open position, in one embodiment of the present subject matter. 
         FIG. 4A  illustrates an exploded view of a hearing aid shell, a faceplate, a microphone housing, a cover, and a fastener, in one embodiment of the present subject matter. 
         FIG. 4B  illustrates an close view of a microphone housing, a cover, and a fastener, in one embodiment of the present subject matter. 
         FIGS. 5A-5B  illustrate a hearing aid according to the present subject matter, in one embodiment of the present subject matter. 
         FIG. 6A  illustrates a hearing aid which does not use a faceplate, in one embodiment of the present subject matter. 
         FIG. 6B  illustrates an at least partially assembled hearing aid made from a housing and a bezel, and not a faceplate, in one embodiment of the present subject matter. 
         FIG. 7A  illustrates a microphone housing for use in a hearing aid, in one embodiment of the present subject matter. 
         FIG. 7B  illustrates a microphone hood installed to a microphone housing, in one embodiment of the present subject matter. 
         FIG. 8  illustrates the receiver assembly, in one embodiment of the present subject matter. 
         FIG. 9  illustrates a hearing aid programmer connected to a hearing aid, in one embodiment of the present subject matter. 
         FIG. 10A  illustrates one method of assembling a hearing aid from a faceplate combined with a shell, according to one embodiment of the present subject matter. 
         FIG. 10B  illustrates one method of assembling a hearing aid from a single piece housing, according to one embodiment of the present subject matter. 
         FIG. 10C  illustrates one method of assembling a hearing aid from a housing combined with a bezel, according to one embodiment of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description of the present invention refers to subject matter in the accompanying drawings which show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter. It will be apparent, however, to one skilled in the art that the various embodiments may be practiced without some of these specific details. References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope is defined only by the appended claims, along with the full scope of legal equivalents to which such claims are entitled. 
       FIG. 1  illustrates a hearing aid  100  according to one embodiment of the present subject matter. In various embodiments, the hearing aid  100  includes a shell  102  of an irregular conical shape, and a faceplate  101 . In various hearing aid designs, to improve performance of the hearing aid, it is beneficial to customize portions of the hearing aid to the hearing aid user. For example, some hearing aid designs benefit from a reduced potential for a feedback loop to form between the hearing aid microphone housing  104  and the hearing aid receiver assembly  105 . Therefore, in some designs, the shell is customized to sealingly mate with the individual user&#39;s hearing canal. However, it should be understood that the present subject matter also includes standardized shells which are suitable for mating to an hearing canal. 
     In various embodiments, the shell  102  includes a large opening adapted for interfacing with a faceplate  101 . In various embodiments, this opening is irregular, requiring that the mating faceplate  101  be customized to fit to it. In various embodiments, a standard faceplate  201 , as pictured in  FIG. 2 , which is larger than the opening, is fitted to the shell, and then modified to a custom shape. In various embodiments, fitting the faceplate to the shell involves using an adhesive at the interface  103  between the oversized faceplate  201  and the shell  102 . In one example, the adhesive is cyanoacrylate. In various examples, the faceplate is then trimmed to blend with the contour of the shell. In one embodiment, the faceplate is trimmed with a routing operation. A hearing aid  100  demonstrating a fitted faceplate  101  is, in one embodiment, suitable for containing various hearing aid components, such as a receiver assembly  105 , a signal processor  106 , a microphone housing  104 , a cover  107  and battery  108 . 
     In various embodiments, additional hearing aid components may be included in the assembly. In one example, a telecoil is included in the assembly. Another example include a wireless transceiver adapted for wireless communications with a hearing aid programmer, or another hearing aid. Various embodiments can include combinations of these devices. Further, in various embodiments, hearing aid components are interconnected with conductors  110 . In other embodiments, at least a portion of the conductors needed to interconnect hearing aid components are attached to a flexible substrate. In some embodiments, the hearing aid components are soldered to flexible printed circuitry (“FPC”). Embodiments using FPC can reduce assembly work by enabling a robot to attach components to the FPC. In such embodiments, final hearing aid assembly requires mating the FPC assembly to the housing, and does not require placement of individual hearing aid components within the housing. 
     By utilizing a design featuring a shell and a faceplate, it is possible to utilize a custom shell  102 , and a standard faceplate  201 , the faceplate adapted to utilize common parts, and further adapted to be customizable to the shell. In various embodiments, the common parts suitable for interface with faceplate  101  include a microphone housing  104 , an insertion removal handle  109 , a cover  107 , and a battery  108 . In further embodiments, a faceplate  101  is adapted to utilize various controls, such as adjusting dials and push-button switches. 
     Thus, the hearing aid improves user comfort due to its customized shape, and is less expensive due to increased use of standard parts. 
       FIG. 2  illustrates a faceplate  201  which has not been mounted to a shell. The illustration demonstrates one embodiment of the form of the faceplate before it is customized to match an opening in a shell. In various embodiments, the faceplate is attached to the shell, using glue or another method to sealingly fix the faceplate  201  to the shell. In further embodiments, the attachment of the faceplate  201  is assisted by using a planning module  202 , which is detachably connected to the faceplate. In various embodiments, when attached to the faceplate  201 , the planning module  202  assists in manipulation of the parts. In further embodiments, the planning module  202  is used after the faceplate is assembled to the hearing aid  100  (pictured in  FIG. 1 ) to assist in manipulation of the hearing aid  100  during other operations, such as assembly and testing. 
       FIG. 3  illustrates a hearing aid  100  using a cover  107 , and shows the cover  107  in an open position. In various embodiments, opening the cover  107  allows access to the battery  108 . In some examples, opening the cover  107  allows access to the components inside the hearing aid. Various embodiments allow the cover  107  to be completely removed from the hearing aid  100 . In various embodiments, the hearing aid  100  is equipped with a fastener  301 . In some examples, the cover  107  is adapted to rotate around the fastener  301 . For example, the cover  107  can have a port through which a fastener, in embodiments where the fastener is shaped like a pin, is inserted. In such embodiments, separating the cover  107  from the hearing aid  100  is not possible unless the fastener  301  is removed from the hearing aid  100 . In other embodiments, the cover  107  can be equipped to clip to the fastener  301 . In such embodiments, the cover  107  can be added to or separated from the faceplate  101  without removing the fastener  301 . 
     In various embodiments, a method of opening the cover  107  allows access to the battery  108 , so that the battery can be removed or replaced when discharged. However, in further embodiments, the cover can also function as a power switch. In various embodiments, opening the cover  107  disconnects the battery  108  from internal components, and consequently, power. In one example, opening the cover  107  disconnects the battery  108  from battery terminals  302 . 
       FIG. 4A  illustrates an exploded view of a hearing aid shell  102 , a faceplate  101 , a microphone housing  104 , a cover  107 , and a fastener  301 . In various embodiments, the faceplate  101  includes an access port  402  adapted to interface and seat the microphone housing  104 . For example, when the microphone housing  104  is inserted into the access port  402 , and the fastener  301  is inserted through the housing mounts  407  and the microphone housing mounts  408 , the microphone housing  104  is constrained and movement is substantially restricted. 
     In one example, the access port includes an interface  409  which is designed to receive the microphone housing  104  at an orientation approximately perpendicular to the plane formed by the interface of the shell  102  and the faceplate  101 , or an equivalent plane. However, in some embodiments, the interface  409  is adapted to receive the microphone housing at various orientations which are skew to the line approximately perpendicular to said plane or its equivalent, in the interest of robustness in manufacturing assembly. It should be noted, however, that once the fastener  301  is inserted, the microphone housing is substantially constrained. 
     In various embodiments, the cover  107  is adapted to clip to the fastener  301 . In some examples, the fastener  301  is pin shaped. In further embodiments, the cover  107  includes a cover mount  403 . In various embodiments, the cover mount is a C-shaped channel which has an interior diameter which is approximately equal to the diameter of the pin. In one example, the curvature of the C-shaped channel  403  forms an arc extending over 180 degrees around the center axis of the C-shaped channel  403 . In this example, the plastic of the cover which forms the C-shaped channel  403  must elastically deform when the cover is clipped into place. Additionally, in such examples, the plastic of the C-shaped channel  403  must elastically deform when the cover is separated from the fastener  301 . In embodiments using a C-shaped channel  403 , the cover  107  is removable from the hearing aid  100  without removing the fastener  301 . In further embodiments not pictured, the cover does not clip to the fastener  301 , but is mounted using a port through which the fastener  301  must pass. One benefit of a clip design is reduced complexity of plastic injection molding tooling, and an ability to remove the door without fastener disassembly. One advantage to a port design is that the cover is attached to the fastener and can better endure an increased range of forces without disassembly. 
     In embodiments using a pin shaped fastener, after the cover  107  is installed, it is free to revolve around the fastener  301 . In some embodiments, rotating the cover  107  toward a seated position engages a locking feature  404 . In various embodiments, closing the cover requires the locking feature  404 , the cover  107 , or a combination of both, to deform elastically while the cover  107  undergoes a seating process which results in the cover being substantially constrained, an example of which being pictured in  FIG. 1 . In various examples, when the cover  107  is seated, the forces causing elastic deformation are relieved, due to the locking feature  404  mating to a relief in the interface  409 . In this position, the cover  107  is substantially constrained. In such embodiments, to remove the cover  107  from a seated position requires forces sufficient to again deform the interfacing components in a manner sufficient to disengage the locking feature  404  from the mating relief. 
     In some embodiments, the cover  107  is adapted to accept a battery, not pictured, in a manner which fixes the orientation of the battery. In various embodiments, fixing the orientation of the battery enables the cover  107 , when seated, to position the battery such that the poles of the battery are located in a desired position in regards to hearing aid components, such as terminals  302 . In various embodiments, the microphone housing  104  includes battery terminals  302  designed to form positive and negative connections to an button battery assembled to the closed cover. In one embodiment, the faceplate  101  is molded with reliefs  401 . One advantage to allowing the battery terminals  302  to deform into a relief  401  is that the gap between the faceplate and the cover can be reduced while maintaining an inexpensive springing battery terminal design. In various designs, if there were no relief, the cover would have to extend beyond the envelope of the button battery to cover the area consumed by the battery terminals  302 . 
     In various embodiments, one aspect of the microphone housing  104  design which improves ease of assembly is the placement of solder pads, not pictured, at the back surface  405  of the microphone housing  104 . Because programming tabs  406  require a high dimensional stability to reliably interface with a programming connector, discussed below, it is important that the plastic proximate to the programming tabs, which holds the programming tabs  406  in place, not be permanently deformed, which can occur in some instances due to a soldering process. Placing solder pads, used to connect the microphone housing to other hearing aid components, on the back surface  405  of the microphone housing  104  relieves the need to depend on precision soldering to avoid deformation of the plastic structure supporting the programming tabs  406 . Moving the solder pads to the back surface  405  of the microphone housing  104  allows the assembly process to tolerate variance in the soldering process, both dimensionally and thermally. This robust design decreases manufacturing defects. 
       FIG. 4B  illustrates, in various embodiments, a cut-away close-up view of microphone housing  104 , programming tabs  406 , battery terminals  302 , housing mounts  408 , and back surface  405 . 
       FIGS. 5A-5B  illustrate one embodiment of a hearing aid  100  according to the present subject matter.  FIG. 5A  shows a hearing aid shell  102  and a faceplate  101 , in which a microphone housing  104  and a cover  107  are installed. The figure also demonstrates a plane A which is used in part to create the cross section picture of  FIG. 5B .  FIG. 5B  illustrates a partial view of the cross section taken by like  5 B- 5 B.  FIG. 5B  includes various parts in cross section, and fastener  301  in an elevated view, for clarity. In this view, it is apparent that in various embodiments, the cover utilizes a C-shaped channel  403 , which is not cut by plane A. In other embodiments, plane A cuts the C-shaped channel  403 , and in further embodiments, the cover  107  includes a port, not pictured, which is cut by plane A. The illustration also demonstrates one embodiment of a manner in which the cover  107 , faceplate  101 , microphone housing  104 , and fastener  301  are assembled together. 
     It should be noted that the concepts enumerated in the figure are not limited to embodiments which utilize both a shell and a faceplate, but extend to other housing variations. For example, in one embodiment, a one piece housing with an access port constrains a microphone housing and cover using a fastener. 
       FIG. 6A  illustrates one embodiment of a hearing aid which does not use a faceplate. In various embodiments, the hearing aid includes a housing  602 , which is a single, seamless piece. In one example, the housing is made using a stereolithography (“SLA”) process. Making a hearing aid out of a one piece housing, instead of two pieces, such as a shell and a faceplate, removes the need for a faceplate, and the costs associated with fitting a faceplate to a shell. In some embodiments, a housing is formed when features adapted for receiving a fastener, and an access port, are created in the housing as part of the SLA process. In other embodiments, the housing is formed when the housing  602  is sealingly combined with a bezel  601 . In various embodiments, the bezel  601  is glued into the housing  602 . Once glued into place, the bezel  601  forms an access port with an interface suitable for receiving a microphone housing  401  and a cover  107 . It should be noted that in various examples, the bezel  601  can be assembled to other components before it is assembled to the housing  602 . 
     Various examples of the bezel  601  utilize a material which has superior mechanical properties when compared to the material from which the housing  602  is made. Further examples utilize a bezel  601  which has improved dimensional accuracy when compared to the process used to make the housing  602 . In various examples, the bezel  601  is a molded polymer. 
       FIG. 6B  illustrates one embodiments of an at least partially assembled hearing aid made from a housing  602  and a bezel  601 , and not a faceplate. In various embodiments, the hearing aid is composed of a housing  602 , a microphone housing  104 , a cover  107 , and a fastener  301 . Additionally, in various embodiments, the hearing aid includes an insertion removal handle  109 . 
       FIG. 7A  illustrates one embodiment of a microphone housing  104  for use in a hearing aid. In various embodiments, the microphone housing  104  is adapted to detachably receive a microphone hood  701 . In various embodiments, the microphone hood  701  includes features which enable it to snap or lock to a microphone housing  104 . In further embodiments, the microphone hood  701  does not snap or lock to the microphone housing  104 , but instead slides into a socket in the microphone housing  104 , and is constrained from detachment after the microphone housing  104  is installed in the hearing aid. In various embodiments, the microphone hood  701  is removable while the microphone housing  104  is installed in the hearing aid. 
     Some embodiments of the present subject matter include a microphone box  705  which is sized for placement in the microphone housing  104 . In various embodiments the microphone housing includes terminals, not pictured, which mechanically connect the microphone box  705  to circuitry in the microphone housing. In some embodiments, the microphone housing  104  is sized so that the microphone box  705  snaps into place, and in others, the microphone box  705  is not constrained until the microphone housing is mated to a hearing aid access port interface. 
     In various embodiments, the microphone hood  701  seals to the microphone housing  104 . One benefit of this seal is to reduce the availability of noise paths between the sound ports  703  and the microphone box  705 . A further benefit is that the seal discourages movement of the microphone hood  701  in relation to the microphone housing  104 . A further benefit is to reduce the instance of rattling between the microphone hood  701  and the microphone housing  104 . In some embodiments, an o-ring  702  is used to seal the microphone hood to the microphone housing. An o-ring seal can be formed of various types, including a face seal, a radial seal, a dovetail seal, a half-dovetail seal, a boss seal, or a crush seal. In other embodiments, another type of seal is used. An additional benefit of the microphone hood  701  is that it protects the microphone housing  104  from being damaged. 
       FIG. 7B  illustrates one embodiment of a microphone hood  701  installed to a microphone housing  104 . The illustration shows a cross section of various parts for clarity. In various embodiments, the microphone hood  701  protrudes from the surface of the microphone housing  104 . In one example, two sound ports  703  are included in the microphone hood  701 . In various embodiments, sound ports  703  are adapted for passage of a cleaning element. For example, an elongated paper clip could pass through them in some embodiments. The availability of an inexpensive cleaning element to clear debris, such as ear wax, is a benefit to the user. In various embodiments, a microphone box, not pictured, is installed in the microphone housing  104  such that the microphone box is sealingly connected to the microphone housing  104 . An o-ring  702  is part of this sealing system in some embodiments. In various examples, sound must travel through the ports  703 , and into the microphone box, in order to affect the hearing aid sound processing electronics. 
     It is to be understood that a removable microphone hood is not limited to embodiments which utilize a microphone housing. In various additional embodiments, a microphone hood is adapted to mate directly to any type of housing, including one formed of a single, seamless piece. In such embodiments, the microphone hood is adapted to lock or snap to the housing so that it is removable only upon a directed effort to remove, and otherwise remains in place during use. A directed effort to remove a microphone hood, in one embodiment, is achieved by an average user pressing the hood with their thumb in an attempt and move it out of a locked position. 
     Among the benefits of the microphone hood of the present subject matter are ease of cleaning, and ease of replacing the hood. A hood which is easy to replace accommodates damage, aesthetic customization, and variations in sound port location. Additionally, a microphone hood socket could connect to other devices. Because the hood can be changed without modifying the hearing aid, changing the hood to accommodate these improvements is inexpensive. 
       FIG. 8  illustrates one embodiment of the receiver assembly, according to the present subject matter. In one embodiment, the receiver assembly includes a flexible receiver tube  802 , and a receiver box  801 . One example of a receiver box  801  includes a speaker which ultimately transmits sound to the user. Some examples of the present subject matter include the flexible receiver tube  802  assembled to the receiver box  801 , comprising the receiver assembly  105  (pictured in  FIG. 1 ). 
     In various embodiments, the receiver tube  802  is constructed from an elastic material. Various examples of the receiver tube  802  are formed such that they mate with a receiver box  801  when they are not stretched. In one example, the receiver tube  802  is stretched around the receiver box  801 , and holds the receiver box in place, as the mating features formed into the receiver tube  802  discourage movement of the receiver box. In various embodiments, the receiver tube  802  exerts a constant pressure on the receiver box due to an elastic deformation induced by assembly of the two components. 
     One benefit of such a receiver tube design is that it is easy to assemble. In various embodiments, the receiver tube  802  does not require alignment with any housing features beyond placing the tube through an opening in the housing, not pictured, sized to receive the receiver tube. In such embodiments, the tube is free to be rotated or tilted while it is mated to the receiver tube opening. Such flexibility in alignment allows an assembly process to install a receiver assembly with reduced effort. In various embodiments, once the receiver assembly is inserted into the shell, the receiver tube is glued to the shell, portions of the receiver assembly are trimmed away. Some embodiments trim the receiver tube to match the contours of the housing. 
       FIG. 9  illustrates a hearing aid programmer connected to a hearing aid, in one embodiment of the present subject matter. In various embodiments, the cover  107  is suitable for interfacing with a programming connector  901 . In one embodiment, a programming connector is inserted between the cover  107  and the microphone housing  104 , such that terminals on the programming connector  901  interface with the programming terminals  406  of the microphone housing  104 , pictured in  FIG. 4 . In one embodiment, the cover  107  is in a closed position, and allows the programming connector to interface with the hearing aid. Interfacing with the hearing aid while the cover is closed is possible because the programming connector  901  is shaped so that it fits in the opening between the closed cover and the microphone housing  104 . In one embodiment, the programming connector  901  is a piece of flexible printed circuitry. In various embodiments, the programming connector  901  is removable without opening the cover  107 . 
       FIG. 10A  illustrates one method of assembling a hearing aid from a faceplate combined with a shell, according to one embodiment of the present subject matter. In the embodiment illustrated, a faceplate is glued to a housing  1004 . In one embodiment, the faceplate is oversized, and attached to the housing. The faceplate is then trimmed and blended to match the contour of the housing  1006 . Various embodiments of the housing include an access port through which hearing aid components can pass, and an interface for a fastener. 
     In various embodiments, the access port includes an interface adapted to seat a microphone housing, and in additional embodiments, an access port interface adapted to seat a cover. In various embodiments, the signal processor and receiver assembly are attached to the microphone housing  1008 . In these embodiments, the microphone housing receiver assembly and signal processor are inserted through the access port, and the microphone housing is seated in the microphone housing interface of the access ports  1010 . In one embodiment, the receiver tube assembly is fed through a receiver tube opening in the housing, and in further embodiments is attached to the housing. Various embodiments trim the receiver tube assembly to fit the user, including trimming the receiver assembly to be flush with the housing. 
     Various embodiments seat the cover to the cover interface in the access port  1012 . In various embodiments, the cover is fastened to the to the microphone housing and faceplate  1014 . In some embodiments, the cover is seated to the faceplate, effectively closing the access port and sealing other components in the housing. Further, in various embodiments, a insertion removal handle is inserted into the faceplate and fixed into position  1016 . 
       FIG. 10B  illustrates one method of assembling a hearing aid from a single piece housing, according to one embodiment of the present subject matter. 
       FIG. 10C  illustrates one method of assembling a hearing aid from a housing combined with a bezel, according to one embodiment of the present subject matter. In embodiments which combine a housing with a bezel, a bezel is glued into the housing  1007 . 
     A hearing aid with a housing, a faceplate, an insertion removal handle, microphone housing, signal processor, receiver assembly, cover, and battery is suitable for use as a hearing aid. It should be noted that the scope of the present subject matter includes the processes described here, and additionally includes processes not enumerated here. As such, variations in the order of the elements is within the scope of the present subject matter. Additionally, variations in the content of the process do not escape the scope of the present subject matter. The process described here is useful to illustrate one method of constructing a modular hearing aid. 
     One benefit of embodiments described above is that fastener assembly allows a robust mount for the cover. A robust mount is better equipped to experience forces without failure. Another benefit is that the components are easy to assemble. A further benefit is that the microphone housing, constrained by its interface with the access port, and the fastener, does not require the added complexity of a snap-in design. Additionally, the ability to fasten the receiver tube to the housing, and then trim it, reduces the sensitivity of the components to orientation as they are assembled. For example, inserting the receiver assembly and the signal processor through the access port and into a particular orientation is difficult. The present subject matter does not require such orientation, and as such, reduces assembly difficulty, which reduces assembly costs. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiment shown. This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. Combinations of the above embodiments, and other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.