Method for fitting a universal hearing device shell and conformal tip in an ear canal

Information

  • Patent Grant
  • 6532295
  • Patent Number
    6,532,295
  • Date Filed
    Friday, December 10, 1999
    25 years ago
  • Date Issued
    Tuesday, March 11, 2003
    22 years ago
Abstract
A method for fitting a hearing device in an ear canal, comprises, providing a receiver module sized and shaped to fit in any of a wide range of ear canals, selecting a conformal tip from a plurality of differently sized conformal tips, each conformal tip of the plurality having an inside circumference adapted to engage the same size receiver module, wherein the selected conformal tip has an outside circumference slightly larger than the circumference of the ear canal, engaging the receiver module within the selected conformal tip, and inserting the selected conformal tip and engaged receiver module into the ear canal.
Description




FIELD OF THE INVENTION




The present invention pertains to hearing aids. More particularly, the present invention pertains to methods for fitting universal hearing devices.




BACKGROUND OF THE INVENTION




The modern trend in the design and implementation of hearing devices is focusing to a large extent on reducing the physical size of the hearing device. Miniaturization of hearing device components is becoming increasingly feasible with rapid technological advances in the fields of power supplies, sound processing electronics and micro-mechanics. The demand for smaller and less conspicuous hearing devices continues to increase as a larger portion of our population ages and faces hearing loss. Those who face hearing loss also encounter the accompanying desire to avoid the stigma and self consciousness associated with this condition. As a result, smaller hearing devices, which are cosmetically less visible, but more sophisticated, are increasingly sought after.




Hearing device technology has progressed rapidly in recent years. First generation hearing devices were primarily of the Behind-The-Ear (BTE) type, where an externally mounted device was connected by an acoustic tube to a molded shell placed within the ear. With the advancement of component miniaturization, modern hearing devices rarely use this Behind-The-Ear technique, focusing primarily on one of several forms of an In-The-Canal hearing device. Three main types of In-The-Canal hearing devices are routinely offered by audiologists and physicians. In-The-Ear (ITE) devices rest primarily in the concha of the ear and have the disadvantages of being fairly conspicuous to a bystander and relatively bulky and uncomfortable to wear. Smaller In-The-Canal (ITC) devices fit partially in the concha and partially in the ear canal and are less visible but still leave a substantial portion of the hearing device exposed. Recently, Completely-In-The-Canal (CIC) hearing devices have come into greater use. As the name implicates, these devices fit deep within the ear canal and are essentially hidden from view from the outside.




In addition to the obvious cosmetic advantages these types of in-the-canal devices provide, they also have several performance advantages that larger, externally mounted devices do not offer. Placing the hearing device deep within the ear canal and close to the tympanic membrane (ear drum) improves the frequency response of the device, reduces distortion due to jaw extrusion, reduces the occurrence of occlusion effects and improves overall sound fidelity. Earlier generation hearing devices function primarily by sound amplification and are typically not altered to user's particular hearing impairment. Modem electronics improvements allow specific sound processing schemes to be incorporated into the hearing device. Similarly, custom programming can be incorporated into the hearing device circuitry allowing a truly custom device for any particular user.




The shape and structure (morphology) of the ear canal varies from person to person. However, certain characteristics are common to all individuals. When viewed in the transverse plane, the path of the ear canal is extremely irregular, having several sharp bends and curves. The overall cross section of the ear canal generally constricts as you move deeper into the ear canal. It is these inherent structural characteristics that create problems for the acoustic scientist and the hearing device designer.




For general discussion purposes, the ear canal can be broken into three main segments. The external and medial segments are both surrounded by a relatively soft cartilaginous tissue. The external segment is largely visible from the outside and represents the largest cavity of the ear canal. The innermost segment of the ear canal, closest to the tympanic membrane, is surrounded by a denser bony material and is covered with only a thin layer of soft tissue. The presence of this bony material allows for little expansion to occur in this region compared with the cartilaginous regions of the ear canal. In addition to being surrounded by cartilage rather than bone, these areas are covered with a substantially thicker tissue layer. Since there is less cushion, pressure exerted by a hearing device on the inner bony region of the canal can lead to discomfort and/or pain, especially when a deep insertion technique is used.




Since the morphology of the ear canal varies so greatly from person to person, hearing aid manufacturers and audiologists use custom manufactured devices in order to precisely fit the dimensions of a user's ear canal. This technique frequently requires impressions of the user's ear canal to be taken. The resulting mold is then used to fabricate a rigid hearing device shell. This process is both expensive and time consuming and the resulting rigid device shell does not perform well during the deformations of the ear canal that occur during normal jaw movement. In order to receive a properly fit hearing device, the user typically has to make several trips to the audiologist for reshaping and resizing. Even after the best possible fit is obtained, the rigid shell rarely provides comfortable hearing enhancement at all times.




Because the resulting hearing aid device shell is typically formed from a hard acrylic material, discomfort to the user is increased when worn for extended periods of time. The inability of the hard shell to conform to normal ear canal deformations can cause it to become easily dislodged from its proper position. Consequently, the quality of the hearing enhancement suffers. Furthermore, due to the added manufacturing costs, it is desirable to utilize a hearing device that is at least partially formed from an off-the-shelf or pre-formed component readily available to the audiologist or physician.




While the performance of CIC hearing devices are generally superior to other larger and less sophisticated devices, several problems remain. Complications typically arise due to the small size of CIC hearing devices and the depth that they are inserted into a user's ear canal.




Because a CIC hearing device forms an essentially air tight seal between the tip of the hearing device and the wall of the ear canal, discomfort to a user is common. This acoustic seal prevents the equalization of pressure between the internal chamber formed between the tympanic membrane and the hearing device, and the outside environment. Due to the sensitivity of the tympanic membrane, even small pressure differentials can cause severe discomfort. Additionally, since the acoustic seal is formed by pressure exerted by the hearing device, this can also lead to discomfort.




Due to their small size and positioning within the ear canal, CIC hearing devices can cause handling problems, making insertion and removal by a user difficult and cumbersome, and can often lead to damage to the hearing device. In the larger, BTE, or ITC hearing devices, the size of the device usually makes it unnecessary to incorporate a retrieval mechanism into its structure, i.e., the wearer normally will not have any difficulty grasping the device in order to remove it. But in smaller hearing devices, such as a CIC device, retrieval cords and other extraction tools become a necessary addition in order to allow for easy and safe removal by the user.




Manufacturing problems may also arise when dealing with CIC hearing devices. The increased complexity of the sound processing electronics and the frequent need to fit all working components into a single housing, causes physical layout problems for the designer and manufacturer. The need to combine various hearing device elements, i.e., integrated circuits, receiver, microphone, capacitors, wiring, etc. into a single small space ultimately adds to the complexity of the manufacturing operation and the overall cost of the device. It is desirable to simplify the layout of the hearing device components and the manufacturing process to accommodate these complex systems. Designing the hearing device to minimize manual procedures during assembly is also desired in a mass production operation.




Further adding to the complexity of known hearing devices, they are usually formatted to be either a right handed or left handed orientation, specifically formatted for a single ear canal. Known hearing devices are therefore not interchangeable. While being substantially symmetric, the ear canals of an individual are not identical and known hearing devices require specific configurations for each ear. It would be beneficial and cost effective to be able to manufacture a hearing device with a single configuration that could be safely and comfortably used in either ear canal and with a variety of users.




The quality of the microphone system that receives sound waves is also critical to the performance of the hearing device. Interference with the microphone reception due to wind or other extraneous noise can lead to a degradation of sound quality. Additionally, vibrations from within a users ear canal and skull, as well as vibrations generated by the hearing device itself can interfere with the operation of the hearing device electronics, particularly the microphone and receiver system. Known hearing devices do not adequately isolate the microphone and receiver elements within the hearing device in order to shield them from this type of interference.




Finally, it is becoming increasingly important to keep the hearing device, and particularly the internal electronics of the hearing device, shielded from extraneous electromagnetic interference. A common problem arises when using a cellular telephone while wearing a hearing device. Magnetic interference generated by the cellular telephone may interfere with the operation of the hearing device electronics and cause a deterioration in sound quality. Shielding from electromagnetic interference is best accomplished by the use of a metal enclosure. Known hearing devices have not been able to adequately utilize metal enclosures because they typically add to the size of the device. Thin walled metal hearing device shells are therefore desired, particularly in the context of a completely in-the-canal device.




U.S. Pat. No. 5,701,348, entitled “Articulated Hearing Device” (“the '348 patent”), discloses a segmented hearing device with several articulating and non-contiguous parts. The hearing device disclosed in the '348 patent includes a rigid receiver module with a surrounding acoustic seal. The device disclosed in the '348 patent is not applicable for complex electronic hearing device systems incorporated into a CIC hearing device. The device taught by the '348 patent does not provide for all of the hearing device components to be included in a single device housing. Additionally, manufacturing the hearing device of the '348 patent is not conducive to automated processes and does not fully take advantage of the available space in the device housing. A large amount of manual labor is still required to assemble the hearing device of the '348 patent.




SUMMARY OF THE INVENTION




The present invention solves the foregoing problems by providing a method for fitting a hearing device in an ear canal utilizing a single receiver module with a variety of differently sized conformal tips, enabling the receiver module to be used in a wide range of ear canals, and interchangeably in either a right or a left ear canal.




In a first aspect of the present invention, a method for fitting a hearing device in an ear canal, comprises, providing a receiver module sized and shaped to fit in any of a wide range of ear canals, selecting a conformal tip from a plurality of differently sized conformal tips, each conformal tip of the plurality having an inside circumference adapted to engage the same size receiver module, wherein the selected conformal tip has an outside circumference slightly larger than the circumference of the ear canal, engaging the receiver module within the selected conformal tip, and inserting the selected conformal tip and engaged receiver module into the ear canal.




Other and further aspects and advantages of the present invention will become apparent hereinafter.











BRIEF DESCRIPTION OF THE DRAWINGS




The drawings illustrate both the design and utility of the preferred embodiments of the present invention, in which similar elements in different embodiments are referred to by the same reference numbers for purposes of ease in illustration of the invention, wherein:





FIG. 1

is a front perspective view of a receiver module utilizing a flexible circuit board assembly constructed in accordance with the present invention;





FIG. 2

is a rear perspective view of the receiver module of

FIG. 1

;





FIG. 3

is a front elevation view of the receiver module of

FIG. 1

;





FIG. 4

is a rear elevation view of the receiver module of

FIG. 1

;





FIG. 5

is a left side elevation view of the receiver module of

FIG. 1

;





FIG. 6

is a right side elevation view of the receiver module of

FIG. 1

;





FIG. 7

is a top plan view of the receiver module of

FIG. 1

;





FIG. 8

is a bottom plan view of the receiver module of

FIG. 1

;





FIG. 9

is an exploded perspective view of the receiver module of

FIG. 1

;





FIG. 10

is a front perspective view of the receiver module of

FIG. 9

with the faceplate removed;





FIG. 11

is a front perspective view of a preferred flexible circuit board assembly constructed in accordance with the present invention;





FIG. 12

is a perspective view of a flexible substrate for use in a circuit board assembly constructed in accordance with the present invention;





FIGS. 12A-12D

are isolated perspective views of respective component mounting regions of the substrate of

FIG. 12

;





FIG. 12E

is a board level schematic of the substrate of

FIG. 12

;





FIG. 13

is a perspective view of the substrate of

FIG. 12

, after a first fold has been made;





FIG. 14

is a perspective view of the substrate of

FIG. 12

, after a second and third fold have been made;





FIG. 15

is a perspective view of the substrate of

FIG. 12

, after a fourth fold has been made;





FIG. 16

is a perspective view of the substrate of

FIG. 12

, after a fifth fold has been made;





FIG. 17

is a perspective view of the substrate of

FIG. 12

, after a sixth and seventh fold have been made;





FIG. 18

is a perspective view of the flexible circuit board assembly constructed in accordance with the present invention, as it aligns with a receiver housing faceplate;





FIG. 19

is a perspective view of the flexible circuit board assembly constructed in accordance with the present invention, as it engages with a receiver housing faceplate;





FIG. 20

is a right side longitudinal cross section of a hearing device utilizing a flexible circuit board assembly constructed in accordance with the present invention;





FIG. 21

is a top longitudinal cross section of a hearing device utilizing a flexible circuit board assembly constructed in accordance with the present invention taken at section marks A—A;





FIG. 22

is a lateral cross section of a hearing device utilizing a flexible circuit board assembly constructed in accordance with the present invention taken at section marks B—B;





FIG. 23

is a lateral cross section of a hearing device utilizing a flexible circuit board assembly constructed in accordance with the present invention taken at section marks C—C;





FIG. 24

is a front perspective view of a hearing device utilizing a flexible circuit board assembly constructed in accordance with the present invention engaged with a conformal hearing aid tip; and





FIG. 25

is a rear perspective view of a hearing device utilizing a flexible circuit board assembly constructed in accordance with the present invention engaged with a conformal hearing aid tip.





FIG. 26

is a rear perspective view of the conformal hearing aid tip shown in FIG.


25


.





FIG. 27

is a rear perspective view of another conformal hearing aid tip having a size that is smaller than the conformal hearing aid tip of FIG.


26


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS





FIGS. 1-10

show various views of a receiver module


10


that is used in conjunction with a completely in-the-canal hearing device. The receiver module


10


comprises a rigid housing that is adapted to contain and protect a variety of hearing device electronics and other operative components, i.e., a hearing device receiver (amplification and speaker system), sound processing circuitry, a microphone, and a power source. Among other features of the receiver module


10


, which will be described in more detail below, it protects the sensitive hearing device components from damage due to moisture, dirt, cerumen (ear wax), and user interference. Additionally, the receiver module


10


preferably prevents electromagnetic energy from interfering with the hearing device electronics.




Preferably, the receiver module


10


is used in combination with a conformal hearing aid tip. U.S. patent application Ser. Nos. [not yet assigned], filed on the same date as the present application, 09/231,282, filed on Jan. 15, 1999, and 09/231,266, filed on Jan. 15, 1999, each disclose and describe several examples of preferred conformal hearing aid tips, the details of which are hereby fully incorporated by reference into the present application.




The receiver module


10


is preferably formed from two pieces, a distal shell


20


and a proximal faceplate


40


. As used herein, the term proximal refers to the portions of a hearing device and its components that are located closer to the exterior, or concha, of an ear canal when the hearing device is inserted. The term distal refers to the portions of a hearing device and its components that are located at a deeper point within an ear canal when a hearing device is inserted. The shell


20


defines an internal chamber


21


and the faceplate


20


defines an internal chamber


41


(Best seen in FIGS.


9


and


10


).




The faceplate


40


includes a door


50


that is hingedly attached to the proximal end of the faceplate


40


. As best seen in

FIG. 1

, the faceplate


40


includes a post


54


that engages within a channel


52


on the door


50


. The door


50


can thus be rotated about the post


54


, allowing access to the chamber


41


through an opening


58


, and, therefore, to components stored therein. Notably, when the door


50


is opened, a flexible circuit board assembly


100


that includes several components, such as battery contacts


190


and


126


and programming pads


120


and


122


(described in more detail below), can be accessed.




The door


50


includes a handle


56


, so that a user can more easily open and close the door


50


. When closed, the door


50


covers the opening


58


. Preferably, the door


50


includes a series of ridges


57


that prevent the door


50


from accidental opening, i.e., without some level of force applied. Preferably, the door


50


does not create an air tight seal and thus allows air to vent between a distal vent


26


and the proximal end of the receiver module


10


.




Also located in the faceplate


40


is a combined wind screen and microphone suspension


44


. The windscreen and microphone suspension


44


includes a dome shaped body


46


on the proximal end of the faceplate


40


and a suspension grommet


47


located within the faceplate


40


. The windscreen and microphone suspension


44


is aligned with a microphone


160


located within the receiver module


10


, and more particularly, within the faceplate


40


. The body


46


includes at least one aperture


48


, which in combination with the shape of the dome


46


allows sound waves to enter a sound port


162


on the microphone


160


while eliminating distortion or extraneous noise due to wind passing near the microphone. The body


46


also prevents dirt and other contaminants from entering the receiver module


10


. The grommet


47


suspends the microphone


160


within the chamber


41


defined by the faceplate


40


, so that vibrations generated by a user's voice or by the hearing device receiver do not interfere with the operation of the microphone


160


.




The grommet


47


aligns the sound port


162


with the wind screen body


46


and the apertures


48


. The apertures


48


allow sound waves to pass through the body


46


and into the sound port


162


. After the microphone receives the sound waves, they are processed, and amplified through a receiver outlet


24


. The receiver outlet


24


is connected to a receiver


150


located within the shell


20


. The vent aperture


26


is also located on the distal end


22


of the shell


20


. The vent aperture


26


allows pressure equalization between the inner regions of the ear canal and the outside environment. Additionally, the vent aperture


26


reduces occlusion effects by allowing sound waves generated within a users own head to propagate to the outside environment rather than resonating within the ear canal.




Since a deep insertion technique is generally preferred when utilizing completely in-the-canal hearing devices, the hearing device is preferably positioned in the narrowest parts of the ear canal. Thus, the shell


20


preferably has a narrower lateral cross-section than the faceplate


40


. Particularly in relation to the faceplate


40


, the shell


20


is tapered at a distal end


22


. Since many of the operative electronics of the hearing device are located within the shell


20


, it is preferable to form the shell


20


from a rigid material that will stand up to substantial pressures exerted by the ear canal wall, as well as potential damage due to handling by a user.




Additionally, since several of the components located within the shell


20


are susceptible to interference by electromagnetic waves given off by items such as cell phone, radios, etc., the shell


20


is preferably constructed from a metal such as stainless steel or aluminum that prevents electromagnetic interference from interfering with the components mounted therein, and will allow a thin construction of the shell


20


without sacrificing strength. Utilizing a metal such as stainless steel or aluminum for the shell


20


allows a smaller device to be constructed, while retaining strength and providing protection from electromagnetic interference. Notably, when a user is adjusting a conformal tip on the receiver housing


10


, pressure is exerted on the shell


20


. Using a metal shell provides a structure that will not shatter or crack when squeezed by a user.




The faceplate


40


is preferably formed from a bio-compatible and hygienic plastic. As discussed above, the faceplate


40


includes a post


54


and an opening


58


to allow access to several of the hearing device components located within the chamber


41


and, more particularly, on the flexible circuit board assembly


100


. In

FIGS. 1

,


2


,


7


, and


8


, the arrow β shows the rotation of the door


50


. Since the receiver module


10


is a programmable hearing device, the faceplate


40


is preferably made from a non-conducting material in order to avoid interfering with any electronic programming connectors inserted through the opening


58


.




When assembled, the shell


20


and the faceplate


40


join to form the contiguous receiver module


10


which creates a singular housing for the hearing device components located within the shell


20


and faceplate


40


.

FIG. 9

shows how the shell


20


and the faceplate


40


align in order to engage with each other. In particular, the faceplate


40


includes a slightly tapered ledge


60


that extends from a peripheral wall


62


of the faceplate


40


. A small portion of the peripheral wall


62


is exposed to form a seat


63


.




As seen in

FIG. 10

, when the shell


20


is engaged with the faceplate


40


, a peripheral wall


65


of the shell


20


abuts against the seat


63


. A tab


64


extends from a bottom portion of the peripheral wall


62


. The tab


64


serves as a key and therefore aids in aligning the faceplate


40


with the shell


20


. In this manner, the shell


20


can only be attached to the faceplate


40


in a single orientation that properly aligns the tab


64


. The tab


64


also helps to secure the two components together. The tapered extension


60


allows the faceplate


40


to be inserted into the shell


20


and secured in place. Preferably, the faceplate


40


is held engaged to the shell


20


by friction between the extension


60


and the inside of the shell


20


, but other fastening systems may be employed and are contemplated by the present invention. For example, notches may be included in the tapered extension


60


that align with recesses in the shell


20


. When the faceplate


40


is engaged with the shell


20


, the notches engage with the recesses and further secure the faceplate


40


to the shell


20


. Squeezing down on the faceplate


40


will disengage the notches from the recesses and allow the faceplate


40


to be removed from the shell


20


.




A shelf


66


is provided within the chamber


41


defined by the faceplate


40


. The shelf


66


divides the chamber


41


into an upper portion


41




a


and a lower portion


41




b,


and isolates the microphone


160


in the upper portion


41




a


when it is inserted into the faceplate


40


. Since a user has access to the lower portion


41




b


through the door


50


, the shelf


66


prevents interference by a user with the operation of the microphone or other sensitive electronics in the upper portion


41




a.







FIG. 10

shows the shell


20


with the flexible circuit board assembly


100


installed within the chamber


21


. In

FIG. 10

, the microphone


160


is shown mounted within the chamber


21


and on the flexible circuit board assembly


100


so that when the faceplate


40


engages with the shell


20


, the microphone


160


will rest within the chamber


41


. The sound port


162


extends from the microphone


160


and is aligned with the apertures


48


on the windscreen and microphone suspension


44


.





FIG. 11

depicts the flexible circuit board assembly


100


isolated from the receiver module


10


and separated from the shell


20


. A foldable substrate


102


provides a base for mounting or otherwise fastening various hearing aid components, such as the microphone


160


, circuit capacitors


180


, an integrated circuit


170


, battery contacts


126


,


190


and


194


, and programming pads


120


and


122


. The foldable substrate


102


also preferably includes various electrical interconnections that connect the hearing device components. While

FIG. 11

depicts the receiver


150


, the receiver is not attached to the foldable substrate


102


, but is rather suspended within the shell


20


, and is shown in

FIG. 11

for reference only.





FIG. 12

shows the foldable substrate


102


in a planar configuration prior to attachment of the microphone


160


, the integrated circuit


170


and the circuit capacitors


180


, and prior to the foldable substrate


102


being folded in accordance with a specific hearing device design. The foldable substrate


102


is preferably formed from a partially or totally flexible dielectric material that is suitable for use in semiconductor circuit board applications and is conducive to known semiconductor manufacturing processes. A preferred example of this type of dielectric substrate is manufactured by Dyconex Technologies under the name DYCOstrate®. 3M Corporation also makes a similar flexible dielectric substrate under the name Kapton®. The foldable substrate


102


is suitable for receipt of electrical traces, contact pads, solder pads, and other electronic components, electrical connectors, and circuit elements. In addition to its electrical and electronic characteristics, the foldable substrate


102


forms the structural backbone of the flexible circuit board assembly


100


.




More particularly, the foldable substrate


102


is configured for the receipt of a particular arrangement of hearing device components such as the microphone


160


, the integrated circuit


170


, and the circuit capacitors


180


. When fully assembled, the foldable substrate


102


and the various components together form the flexible circuit board assembly


100


, which can be coupled to the hearing aid receiver


150


in order to function as a complete hearing amplification and sound processing system. After assembly, the flexible circuit board assembly


100


is formatted to be inserted as a unit into the shell


20


and faceplate


40


forming the receiver module


10


.




The flexible circuit board assembly


100


provides a stock configuration with respect to the mechanical and electrical core components of the receiver module


10


, which do not need to be modified for a particular individuals ear canal size. A hearing device that utilizes such a flexible circuit board assembly


100


can be physically adjusted in order to fit various ear canal sizes by the use of a soft conformal tip.




By making the construction of the receiver module universal, the receiver module can be easily used in either a right or left ear canal rather than being restricted to a particular ear. With the use of a soft conformal tip, the receiver module can be used in a variety of differently sized ear canals as well, truly making a receiver module constructed in accordance with the present invention universal and in conjunction with a conformal tip, a “one-size-fits-all” hearing device.




With continuing attention to FIG.


12


and as shown in greater detail in

FIGS. 12A-12D

, a the foldable substrate


102


includes a first component mounting region


104


, a second component mounting region


106


, a third component mounting region


108


, and a fourth component mounting region


110


. Each of the component mounting regions


104


,


106


,


108


, and


110


are interconnected to each other to form the foldable substrate


102


. Further, each of the component mounting regions


104


,


106


,


108


, and


110


includes at least one flexible portion defined by etchings in the substrate that allow each of the respective component mounting regions to be folded into a desired configuration without affecting the performance or strength of the foldable substrate


102


, or any of the components attached to it.




As shown in

FIGS. 12 and 12A

, the first component mounting region


104


includes flexible portion


112




a,


bordered by etchings


112




a


-


1


and


112




a


-


2


, flexible portion


112




b


bordered by etchings


112




b


-


1


and


112




b


-


2


, and flexible portion


112




c


bordered by etchings


112




c


-


1


and


112




c


-


2


. The second component mounting region


106


, shown in

FIGS. 12 and 12B

includes flexible portion


116




a


bordered by etchings


116




a


-


1


and


116




a


-


2


, and flexible portion


116




b


bordered by etchings


116




b


-


1


and


116




b


-


2


. The third component mounting region


108


, shown in

FIGS. 12 and 12C

, includes flexible portion


128




a


bordered by etchings


128




a


-


1


and


128




a


-


2


, and the fourth component mounting region


110


, shown in

FIGS. 12 and 12D

, includes flexible portion


118




a


bordered by etchings


118




a


-


1


and


118




a


-


2


.




For ease of illustration, the divisions between the four component mounting regions


104


,


106


,


108


, and


110


are shown in

FIGS. 12-12D

with a thickened line at etchings


116




a


-


1


,


116




b


-


1


, and


118




a


-


2


. For instance, etching


116




a


-


1


is the border between the first component mounting region


104


and the second component mounting region


106


. Etching


116




b


-


1


is the border between the second component mounting region


106


and the third component mounting region


108


. Etching


118




a


-


2


is the border between the third component mounting region


108


and the fourth component mounting region


110


. It is noted that the configuration of the substrate


102


shown in

FIGS. 12-12D

is by example only and other arrangements of the several component mounting regions are contemplated by the present invention. By way of example only, more or less than four component mounting regions can be utilized depending on the particular configuration desired in the hearing device. Additionally, the number of etchings and flexible portions on each particular component mounting region is not limited to the particular configuration shown in

FIG. 12

, and can be varied for different hearing device and flexible circuit board assemblies. Additionally, the flexible portions can be defined by a single etching, rather than a pair of substantially parallel etchings.




During the manufacturing process of the foldable substrate


102


, several of the hearing device components are incorporated. In particular, the first component mounting region


104


is provided with three microphone contacts, one for the microphone connection, one for the Regulated Voltage going to the microphone (VREG) connection, and one for a grounding connection. The third component mounting region


108


is provided with two receiver wire contacts


130


and


131


, as well as a positive battery contact


194


. The fourth component mounting region


110


is provided with programming pads


120


and


122


as well as a negative battery contact


190


and a ground contact


126


. Programming pad


120


is preferably for a clock signal (SCLOCK) to the integrated circuit during a programming sequence, and programming pad


122


is preferably for a data signal (SDA) to the integrated circuit during a programming sequence. During the manufacturing process of the substrate


102


, the integrated circuit


170


and the circuit capacitors


180


are also attached to the second component mounting region


106


.





FIG. 12E

shows a board level schematic of a foldable substrate


102


.

FIG. 12E

shows incorporated onto the foldable substrate


102


, the various electrical components and connectors as well as the interconnective electrical and electronic pathways between the components and connectors. Together, these elements form a multi-layer flexible circuit board that can be folded into the flexible circuit board assembly


100


in accordance with the present invention. Notably, a series of electrically conductive pathways


200


,


202


, and


204


interconnect the programming pads


120


and


122


, the battery contacts


126


,


190


, and


194


, the microphone contacts


114


, the receiver wire pads


130


and


131


, the integrated circuit


170


, and the circuit capacitors


180


. Solder pads


172


and


182


are also included on the foldable substrate


102


in order to facilitate attachment of components such as the integrated circuit


170


, the circuit capacitors


180


, and the various contact pads. The electrically conductive pathways


200


,


202


, and


204


are preferably a combination of traces along the surface of the substrate


102


, and vias or microvias between the different layers of the substrate


102


. Attaching the integrated circuit


170


and the capacitors


180


can be accomplished by a “wire bond” process or by a “flip chip” process, both of which are well known in the field of printed circuit board design and manufacturing. In the context of a flexible substrate, these processes are commonly referred to as “wire bond on flex” and “flip chip on flex”. Other types of surface mount (SMT) processes can be used and are contemplated by the present invention.




Referring to

FIGS. 13-17

, the foldable substrate


102


is shown in various stages as it would preferably be folded, and as hearing device components are preferably incorporated in order to complete the flexible circuit board assembly


100


. It is noted that the integrated circuit


170


and the circuit capacitors


180


are preferably incorporated onto the foldable substrate


102


during its initial manufacturing, and prior to the foldable substrate


102


being folded into the flexible circuit board assembly


100


. However, for ease of illustration, the integrated circuit


170


and the circuit capacitors


180


are not shown attached to the substrate


102


in

FIGS. 13-16

.





FIG. 13

shows the foldable substrate


102


after a first fold has been made. In

FIG. 13

, the flexible portion


116




b


is bent approximately 90 degrees so that the third component mounting region


108


and the fourth component mounting region


110


are substantially perpendicular to the first component mounting region


104


and the second component mounting region


106


. In

FIG. 13

, the third component mounting region


108


and the fourth component mounting region


110


can be seen from their bottom surface, including the negative battery contact


194


.





FIG. 14

shows the foldable substrate


102


after a second and a third fold have been made. First, the flexible portion


118




a


is bent approximately 90 degrees so that the fourth component mounting region


110


is substantially parallel to the first and second component mounting regions


104


and


106


. It is noted however that after the second fold has been made, the fourth component mounting region


110


is in a different plane than the first and second mounting regions


104


and


106


due to the first fold having been previously made. The second fold is made so that the upper surface of the fourth component mounting region


110


is facing in substantially the same direction as it was before the first fold was made.




Next, flexible portion


128




a


is bent so that the third component mounting region


108


, and particularly the surface of the third component mounting region that includes the receiver wire pads


130


and


131


, faces toward the fourth component mounting region


110


. Preferably, the third component mounting region


108


is bent approximately 45 degrees from its previous position.





FIG. 15

shows the foldable substrate


102


after a fourth fold is made, and how the microphone


160


is installed. In

FIG. 15

, the flexible portion


116




a


is bent approximately 90 degrees so that the first component mounting region


104


is substantially perpendicular to the second component mounting region


106


. After the fourth fold is made, the microphone


160


is positioned on the first component mounting region


104


so that contacts on the microphone (not shown) align with the contacts pads


114


on the first component mounting region


104


. The microphone


160


is preferably bonded onto the first component mounting region


160


in order to ensure a permanent physical and electrical connection.





FIG. 16

shows the foldable substrate


102


after a fifth fold is made. In

FIG. 16

, the flexible portion


112




c


is bent approximately 90 degrees so that the first component mounting region


104


is again parallel to the second and fourth component mounting regions


106


and


110


. It is noted however that after the fifth fold is made, the first component mounting region


104


is in a different plane than the first and second mounting regions


104


and


106


due to the previous folds of the substrate


102


. After the fifth fold is made, and because the microphone


160


was previously attached to the first component mounting surface


104


, the sound port


162


on the microphone


160


faces a proximal end


103


of the foldable substrate


102


.





FIG. 17

shows the substrate


102


after a sixth and seventh fold are made. First, flexible portion


112




a


is bent approximately 90 degrees so that the length of the microphone


160


is substantially perpendicular to its prior orientation. Next, the flexible portion


112




b


is bent approximately 90 degrees and in the same direction as the previous fold, so that the length of the microphone


160


is in the same orientation as it was before the sixth fold was made. After flexible portions


112




a


and


112




b


have been bent, the first component mounting region


104


is wrapped around the microphone


160


. Since the microphone has now been flipped 180°, the sound port


162


faces toward the proximal end


103


of the foldable substrate


102


.

FIG. 17

also shows the integrated circuit


170


and the circuit capacitors


180


attached to the second component mounting region


106


of the substrate


102


. As mentioned above, the integrated circuit


170


and the circuit capacitors


180


are preferably attached to the foldable substrate


102


during the manufacturing process of the substrate


102


itself. However, for ease of illustration, the integrated circuit


170


and the circuit capacitors


180


were not shown attached to the substrate


102


in conjunction with

FIGS. 13-16

.





FIG. 17

shows receiver wires


132


and


134


attached to the receiver wire pads


130


and


131


. The receiver wires


132


and


134


lead from the contact pads


130


and


131


to the receiver


150


(not shown). When the hearing device is fully assembled, the receiver


150


is suspended within the shell


20


and preferably does not contact the foldable substrate


102


or the integrated circuit


170


. Suspending the receiver


150


within the shell


20


reduces feedback problems and prevents vibrations generated by the hearing device or a user from interfering with the operation of the hearing device. U.S. patent application Nos. [not yet assigned], filed on the same day as the present application, and 09/317,485, filed on May 24, 1999, teach and describe preferred embodiments of such a receiver suspension, the details of which are hereby fully incorporated by reference into the present disclosure. The use of the receiver wires


132


and


134


to connect the receiver contact pads


130


and


131


with the receiver


150


, reduces feedback problems by further isolating the receiver


150


from the rest of the hearing device, preventing vibrations generated by the receiver


150


from propagating toward the microphone


160


.




The receiver wires


132


and


134


are attached to the receiver wire pads


130


and


131


prior to the foldable substrate


102


being folded. Additionally, the receiver


150


is already attached to the receiver wires


132


and


134


. In general it is preferable to make all solder connections to the foldable substrate


102


prior to folding the foldable substrate


102


. FIG.


17


and the preceding figures do not show these elements for ease of illustration only.




In

FIG. 18

the assembled flexible circuit board assembly


100


is shown as it aligns with the faceplate


40


and prior to being inserted into the faceplate


40


. In

FIG. 19

the assembled flexible circuit board assembly


100


is shown after being inserted into the faceplate


40


. When inserted into the faceplate


40


, a shelf


66


within the chamber


41


separates several of the component mounting regions on the flexible circuit board assembly


100


. Namely, the first component mounting region


104


and the microphone


160


are positioned within an upper chamber


41




a


and the fourth component mounting region


110


is within a lower chamber


41




b.


As best seen in

FIG. 19

, when the flexible circuit board assembly


100


is inserted into the faceplate


40


, the third component mounting region


108


and the second component mounting region


106


extend out of the faceplate


40


.




Referring to

FIGS. 20-23

, the flexible circuit board assembly


100


is shown positioned within the shell


20


and the faceplate


40


. As discussed above, the proximal end of the faceplate includes a windscreen and microphone suspension


44


. The dome shaped cover


46


along with the apertures


48


, prevent noise due to wind or other extraneous noise from interfering with the reception of the microphone


160


. Further, the cover


46


prevent debris, dust, hairspray or other contaminants, from entering the microphone


160


, and from potentially interfering with the operation of the hearing device. A suspension grommet


47


extends through the faceplate


40


from the cover


46


and engages with the sound port


162


on the microphone


160


. The suspension grommet


47


positions the sound port


162


directly in front of the apertures


48


and directs sound waves into the sound port


162


. The suspension grommet


47


also helps secure and align the microphone


160


within the faceplate


40


. The microphone


160


is also preferably surrounded by a flexible skirt


164


(Best seen in FIG.


21


), that helps position the microphone


160


within the faceplate


40


and ensures that the microphone


160


does not come into contact with the walls of the faceplate


40


. The flexible skirt


164


is preferably made from a flexible rubber or polyurethane material and reduces the effects of vibrations on the microphone


160


.




A receiver module


10


as described herein, is preferably used in conjunction with a conformal hearing aid tip.

FIGS. 24 and 25

depict a receiver module


10


incorporating a flexible circuit board assembly constructed in accordance with the present invention, engaged within a conformal tip


200


. The conformal tip


200


is preferably a soft foam sheath with a bulbous end that is adapted to engage with the wall of an ear canal, provide an acoustic seal, and reduce discomfort to the user. U.S. patent application No. [not yet assigned], filed on the same day as the present application, teaches and describes a preferred embodiment of such a conformal tip


200


, the details of which are hereby fully incorporated by reference into the present application. Preferably, the conformal tip


200


includes a retrieval cord


210


. Alternately, the retrieval cord


210


can include a vent tube which provides pressure equalization between the inner regions of the ear canal and the outside environment. The conformal tip


200


can be made in different sizes as shown in

FIGS. 26 and 27

, which depict a conformal tip


200


that is larger than another conformal tip


300


. The receiver module can be used interchangeably with both conformal tip


200


and conformal tip


300


.





FIG. 21

also shows how the sound port


162


engages within the suspension grommet


47


and how the receiver


150


engages within the receiver grommet


154


. The receiver grommet


154


further aids in securing the receiver


150


within the shell


20


.




When building a hearing device, and particularly a completely in-the-canal hearing device, a flexible circuit board assembly, such as the flexible circuit board assembly


100


described above, is preferably adapted for a mass production or assembly line manufacturing process. The original planar configuration of the flexible circuit board assembly


100


of the present invention lends well to mass production and contributes to reduced cost and manufacturing time.




A receiver module


10


as described herein, is preferably used in conjunction with a conformal hearing aid tip.

FIGS. 24 and 25

depict a receiver module


10


incorporating a flexible circuit board assembly constructed in accordance with the present invention, engaged within a conformal tip


200


. The conformal tip


200


is preferably a soft foam sheath with a bulbous end that is adapted to engage with the wall of an ear canal, provide an acoustic seal, and reduce discomfort to the user. U.S. patent application No. [not yet assigned], filed on the same day as the present application, teaches and describes a preferred embodiment of such a conformal tip


200


, the details of which are hereby fully incorporated by reference into the present application. Preferably, the conformal tip


200


includes a retrieval cord


210


. Alternately, the retrieval cord


210


can include a vent tube which provides pressure equalization between the inner regions of the ear canal and the outside environment.




Although the invention has been described and illustrated in the above description and drawings, it is understood that this description is by example only and that numerous changes and modifications can be made by those skilled in the art without departing from the true spirit and scope of the invention. The invention, therefore, is not to be restricted, except by the following claims and their equivalents.



Claims
  • 1. A method for fitting a hearing device in an ear canal, comprising:providing a receiver module sized and shaped to fit in any of a wide range of ear canals; selecting a conformal tip from a plurality of differently sized conformal tips, each conformal tip of the plurality having an inside circumference adapted to engage the same size receiver module, wherein the selected conformal tip has an outside circumference slightly larger than the circumference of the ear canal; engaging the receiver module within the selected conformal tip; and inserting the selected conformal tip and engaged receiver module into the ear canal.
  • 2. The method of claim 1, wherein the conformal tip comprises a soft foam sheath having a bulbous distal end.
  • 3. The method of claim 1, wherein the conformal tip comprises a non-compressible gel having an elastic membrane sheath.
  • 4. The method of claim 1, further comprising:determining if the selected conformal tip and engaged hearing device forms an acoustic seal within the ear canal; and if the hearing device does not form an acoustic seal; removing the selected conformal tip and engaged receiver module from the ear canal; selecting a second conformal tip from the plurality of differently sized conformal tips; engaging the receiver module within the second conformal tip; and inserting the selected second conformal tip and engaged receiver module into the ear canal.
  • 5. The method of claim 1, wherein the receiver module comprises a shell formed from a rigid material that provides protection from electromagnetic interference, to electronic components housed within the shell.
  • 6. The method of claim 5, wherein the shell is formed from stainless steel.
  • 7. The method of claim 5, wherein the shell is formed from aluminum.
  • 8. The method of claim 1, wherein the conformal tip comprises means for reducing occlusion effects.
  • 9. The method of claim 1, wherein the conformal tip comprises a vent aperture.
  • 10. The method of claim 1, further comprising the step of allowing air to escape through the vent tube housed within the retrieval cord.
  • 11. The method of claim 1, further comprising the step of readjusting the position of the hearing device using the retrieval cord.
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