[0001] Hearing aids utilize a variety of designs, reflecting not only the hearing deficiencies
for which they are designed, but just as importantly the fashion, comfort and cost
requirements of the user. For example, although a behind-the-ear (BTE) hearing aid
may be inexpensive to manufacture and thus relatively inexpensive to purchase, some
users may be unwilling to use this style hearing aid because they find it uncomfortable
for extended use or because they find the design too conspicuous. In an attempt to
provide a less conspicuous form of hearing aid, many manufacturers have developed
in-the-ear (ITE) designs that either partly or completely reside within the user's
ear canal. Due to their size and position during use, however, ITE hearing aids present
unique miniaturization, fabrication and fit problems.
[0002] Conventional ITE hearing aids are comprised of a rigid mounting plate, commonly called
a faceplate, and a contoured shell designed to fit within the user's ear canal. Typically
the electronics associated with the hearing aid, including the input transducer or
microphone, signal processor, output transducer or speaker and battery compartment,
are attached to the faceplate. The faceplate may also include a programming port,
volume control, on/off switch and/or other desirable feature. During fabrication of
a conventional ITE hearing aid, normally the electronics are first attached to an
over-sized faceplate and then the shell is bonded to the faceplate. After the adhesive
has cured, excess faceplate material is trimmed and sanded away.
[0003] There are several drawbacks associated with conventional ITE hearing aids. First,
the fabrication process is very labour intensive, thus leading to high manufacturing
costs. Second, the shells are often individually sized and shaped, further impacting
manufacturing costs. Third, due to the limited flexure offered by a typical shell,
the user may experience discomfort, especially after extending wear. Fourth, as the
shell is bonded to the faceplate, maintenance of the hearing aid after fabrication
requires that the hearing aid be cracked or machined open, adding to the time and
expense associated with repairs. Fifth, as the user talks or otherwise flexes their
jaw muscles, changes in the shape of the user's ear canal results in variations in
the seal between the ear canal and the outer surface of the conventional shell, leading
to sound leaks which are a source of signal feedback.
[0004] Compliant or "soft" ITE hearing aids may overcome many, if not all, of the deficiencies
associated with conventional ITE hearing aids. These hearing aids are often similar
to conventional ITE hearing aids in design except that the shell comprises a flexible
material, thus providing a much more comfortable fit within the user's ear canal.
Unfortunately, the use of a shell comprising a material different from that used to
manufacture the faceplate, and in particular a shell comprising a silicone or other
soft material, presents unique fabrication problems. In particular, attaching the
soft shell to the faceplate is difficult using the conventional approach as most adhesives,
especially quick setting or "instant" adhesives, do not bond well to many soft shell
materials (e.g., silicones). In some cases the adhesive may form an initially sound
bond, but then the bond strength will weaken after exposure to moisture. If a slower
setting adhesive is used in order to achieve better bond strength, more complex holding
fixtures are required to hold the components in place during the curing cycle. Thus
slower setting adhesives add to fabrication complexity and cost while slowing down
the fabrication process. In addition, once the shell is bonded to the faceplate, it
is extremely difficult to detach the shell from the faceplate, for example to allow
routine maintenance, without tearing the shell material or otherwise damaging the
device.
[0005] Accordingly, what is needed in the art is an ITE hearing aid that is simple to fabricate
and that allows detachment of the shell from the faceplate without damaging one or
both components. The present invention provides such an ITE hearing aid.
[0006] The present invention provides a method of fabricating a modular hearing aid as well
as the resultant hearing aid. The hearing aid of the invention comprises a shell and
a faceplate assembly. The shell may be formed of a soft, flexible material or a rigid
or semi-rigid material. The faceplate assembly comprises at least a pair of pieces,
preferably an upper faceplate piece and a lower faceplate piece. During assembly,
a portion of the shell is captured within the faceplate assembly, for example between
the upper and lower faceplate pieces. The upper and lower pieces of the faceplate
can be attached to one another using any of a variety of techniques, including miniature
screws, interlocking and complementary members, fastening clips or other means. Preferably
the upper and lower faceplate pieces are releasably coupled to one another, thus allowing
easy disassembly of the device for maintenance or internal calibration. The upper
and lower pieces can also be attached to one another using a permanent or semi-permanent
means, although using permanent means limits the ease with which the device can be
disassembled.
[0007] A further understanding of the nature and advantages of the present invention may
be realized by reference to the remaining portions of the specification and the drawings.
- Fig. 1
- is an illustration of a conventional ITE hearing aid;
- Fig. 2
- is a top view of a faceplate;
- Fig. 3
- illustrates where the shell is to be attached to the faceplate shown in Fig. 2;
- Fig. 4
- is a cross-sectional view of the ITE hearing aid of Fig. 1 prior to removal of excess
faceplate material;
- Fig. 5
- is a cross-sectional view of an ITE hearing aid fabricated in accordance with the
invention;
- Fig. 6
- is a perspective view of an ITE hearing aid similar to that shown in Fig. 5;
- Fig. 7
- illustrates a method of capturing a "T" portion of a shell between an upper faceplate
piece and a lower faceplate piece;
- Fig. 8
- illustrates an alternative to the capture technique shown in Fig. 7, in which only
a single lip is captured between the faceplate pieces;
- Fig. 9
- illustrates another alternative to the capture technique shown in Fig. 7, in which
the shell is merely clamped between the upper and lower faceplate pieces and in which
no lip is used to insure shell retention;
- Fig. 10
- illustrates another alternate shell capture technique in which a spherically-shaped
portion of the shell is completely captured by the faceplate assembly;
- Fig. 11
- illustrates another alternate shell capture technique in which the gripping surfaces
of the upper and lower faceplate pieces have been treated;
- Fig. 12
- illustrates another alternate shell capture technique in which the surfaces of the
shell that are gripped by the upper and lower faceplate pieces have been treated;
- Fig. 13
- illustrates a method of capturing a portion of a shell between the inner and outer
side surfaces of the upper and lower faceplate pieces, respectively;
- Fig. 14
- illustrates an alternate method of capturing a portion of a shell between the inner
and outer side surfaces of the upper and lower faceplate pieces, respectively;
- Fig. 15
- illustrates an alternate method of capturing a portion of a shell between first and
second faceplate pieces, the method utilizing an additional sealing member;
- Fig. 16
- illustrates an alternate method of capturing a shell by a faceplate assembly, the
method utilizing an intermediary member interposed between the faceplate assembly
and the shell;
- Fig. 17
- illustrates a pair of interlocking members that can be used with the present invention
to hold together the upper and lower faceplate pieces;
- Fig. 18
- illustrates a single locking member and a complementary locking portion that can be
used with the present invention to hold together the upper and lower faceplate pieces;
and
- Fig. 19
- illustrates an embodiment in which the locking members use complementary grooves and
ridges to hold together the upper and lower faceplate pieces.
[0008] Figs. 2-4 illustrate a few of the basic steps required to fabricate the conventional
ITE hearing aid 100 illustrated in Fig. 1. Fig. 2 is a top view of a faceplate 201
to which several components are shown attached, including a battery compartment 203,
a microphone 205 and a volume control 207. Several additional components are shown
that are not attached to faceplate 201, but further comprise the electronics associated
with the hearing aid, including amplifier 209 and speaker 211.
[0009] Fig. 3 is a second view of faceplate 201 showing, via shadow line 301, the intended
point of attachment of the shell. As further illustrated in the cross-sectional view
provided in Fig. 4, shell 401 attaches to faceplate 201 at a juncture 403. Typically
the attachment of shell 401 to faceplate 201 is accomplished with a quick-set bonding
agent. After the bonding agent has sufficiently cured, a portion of faceplate 201
is trimmed away by cutting along a line 303. The remaining portion of faceplate 201
that extends past shell 401 is then removed, typically by a process of hand buffing
and polishing the edge of faceplate 201 until its edge is smooth and in-line with
the edge of shell 401 (i.e., faceplate edge 405).
[0010] According to the present invention and as illustrated in the cross-sectional view
shown in Fig. 5 and the perspective cross-sectional view shown in Fig. 6, the hearing
aid faceplate assembly comprises at least two pieces such as a first (e.g., upper)
faceplate piece 501 and a second (e.g., lower) faceplate piece 503 which, when joined
together, capture an edge or end portion 505 of a shell 507. In the preferred embodiments,
shell 507 is a compliant or soft shell fabricated from any suitable, flexible material
such as an elastomer, silicone, latex, polyurethane, polyvinyl, or polymer. If shell
507 comprises a compliant or soft material, it can be fabricated in a variety of ways
known to those of skill in the manufacturing arts, for example, as disclosed in U.S.
Patent No. 6,393,130 or U.S. Patent Application Nos. US2001/0008560 or US2002/0025055,
the disclosures of which are incorporated herein in their entirety for any and all
purposes, or by any other means known by those of skill in the art. The individual
pieces that comprise the faceplate assembly are preferably fabricated from a rigid
or semi-rigid material, for example a metal, plastic or ceramic. It is understood
that the individual pieces that comprise the faceplate assembly can be fabricated
from different materials, for example, the lower faceplate piece can be fabricated
from a metal while the upper faceplate piece can be fabricated from a plastic.
[0011] Attached to the faceplate assembly are the various elements that may comprise hearing
aid 500, preferably in a design layout that is acoustically stable when the hearing
aid is assembled. Shown in Figs. 5 and 6 are a battery compartment 509 (with a battery
511 shown), a microphone 513, and a processor/amplifier 515. Fig. 5 also shows a speaker
517 coupled to the end portion of shell 507 via a sound tube 519. Figs. 5 and 6 also
show a microphone port 521 and a battery compartment door 523 attached to upper faceplate
portion 501. It will be appreciated that the components shown in Fig. 5 and, in part,
in Fig. 6, are for illustration purposes only and that the present invention is not
limited to hearing aids or other devices that include the same set of components.
For example, the system could also include a push-button on/off switch (not shown),
a volume control (not shown), programming switch (not shown), telecoil (not shown)
and/or a vent tube (not shown). It will also be appreciated that the configuration
illustrated in these figures is meant for illustrative purposes only and that the
invention is equally applicable to other configurations. For example, all of the electronic
components comprising the hearing device can be attached to the upper faceplate piece
and, during assembly, can pass through an open portion of the lower faceplate piece.
[0012] In a preferred embodiment of the invention, faceplate assemblies are fabricated in
advance of need, with the locations of the various components being independent of
the shell that is to be eventually mated to a particular faceplate assembly. If desired,
faceplate assemblies can be pre-fabricated with various component combinations (e.g.,
with/without on/off switch, with/without volume control, etc.), thus allowing an inventory
of likely configurations to be accumulated. Furthermore, the faceplate assemblies
can be pre-fabricated in more than one size, thus providing the installer more flexibility
in fitting a particular sized shell to the faceplate assembly. Lastly, due to the
modular design, a few lower faceplate assemblies along with a variety of cosmetically
different upper faceplates and shells can be used to fabricate any of a large variety
of individualized hearing aids from a relatively small inventory.
[0013] Figs. 7-16 illustrate a variety of techniques that may be used to capture a shell
with a faceplate assembly. Preferably and as illustrated in Figs. 7-14, a portion
of the shell is captured between a pair of faceplate pieces, i.e., first and second
faceplate pieces, the pair of faceplate pieces comprising the faceplate assembly.
It will be appreciated, however, that the faceplate assembly can comprise more than
a pair of pieces (e.g., the configuration shown in Fig. 15) or that the faceplate
assembly can attach to an intermediary member that then, in turn, attaches to the
shell (e.g., the configuration shown in Fig. 16).
[0014] Fig. 7 provides a close-up of the capture technique shown in Figs. 5 and 6. As illustrated,
a "T" retention member 701 of shell 703 is captured within the faceplate assembly
cavity that is formed by the assembly of faceplate pieces 705 and 707, retention member
701 holding shell 703 in place. It will be appreciated that although a retention member
can be used as the sole capture mechanism, shell retention can be augmented by gripping
or compressing edge portion 709 between complementary faceplate surfaces 711 and 713,
the amount of holding force being proportional to the force applied by complementary
surfaces 711 and 713 and thus dependent upon the means used to couple the faceplate
assembly. To insure a secure shell mount, preferably both edge compression and a retention
member are used.
[0015] It will be appreciated that although the retention member shown in Fig. 7 employs
a "T" shape, the invention could also utilize other shapes (e.g., spherical, irregular,
etc.). For example, shell 703 could utilize a single lip 801 ("L" shaped) as shown
in Fig. 8. As previously noted, preferably the shell is held not only by capturing
retention member 801 within the faceplate assembly, but also by clamping or compressing
an edge portion of the shell between the two faceplate pieces.
[0016] In another preferred embodiment, shell 703 does not include a retention member and
relies solely on the clamping feature of the faceplate assembly to hold the shell
in place. Thus as illustrated in Fig. 9, shell edge portion 709 is held by compressing
the edge portion between complementary faceplate surfaces 711 and 713.
[0017] Fig. 10 illustrates an alternate shell capture technique in which a shaped portion
1001 of shell 1003 is completely captured between adjacent and complementary surfaces
1005 and 1007 of first faceplate piece 1009 and second faceplate piece 1011, respectively.
Although in the illustrated embodiment portion 1001 is spherically shaped, it will
be appreciated that other shapes could also be used (e.g., T-shaped, L-shaped, irregularly
shaped, etc.). In this embodiment, the capture mechanism can solely rely on the shaped
portion 1001 being held in a similarly shaped cavity formed by the combination of
surfaces 1005 and 1007. Alternately, the capture mechanism can rely both on the shaped
portion 1001 fitting within the complementary cavity formed by the faceplate assembly
and on the compressive forces applied by surfaces 1005 and 1007 to shaped portion
1001 and to any other shell material that is captured by the complementary faceplate
surfaces.
[0018] Figs. 11 and 12 illustrate yet another alternate shell capture technique. In this
embodiment, one or more of the complementary surfaces of the faceplate pieces and
the shell are textured, treated or formed to enhance the ability of the faceplate
assembly to seize and retain the shell. Surface treatment can either take place after
the component is fabricated (e.g., coating a fabricated surface, roughening a surface,
etc.) or during fabrication (e.g., moulding a roughened surface on the complementary
surfaces of the faceplate pieces, etc.). For example as shown in Fig. 11, surfaces
1101 of upper faceplate 1103 and lower faceplate 1105 are serrated, thus allowing
them to better grip surfaces 1107 of shell portion 1109. Alternately as shown in Fig.
12, surfaces 1201 of shell portion 1203 have been treated (e.g., serrated) while surfaces
1205 of upper faceplate 1207 and lower faceplate 1209 are untreated. It will be appreciated
that the mating surfaces of the shell and the faceplate pieces can both be treated.
It will also be appreciated that the surface treatment can include serrations or other
forms of surface roughening or texturing, surface coatings (e.g., application of an
elastomeric material on the gripping surfaces), adhesives or any other type of surface
treatment that improves the retention characteristics of the faceplate assembly. It
will also be appreciated that the surface treatments disclosed above could be used
with any of the disclosed shell capture techniques (e.g., those illustrated in Figs.
7-10 and Figs. 13-14), thereby enhancing the ability of the faceplate surfaces to
grip the shell.
[0019] As previously disclosed, the present invention is not limited to faceplate assemblies
comprised only of pairs of faceplates, nor is the invention limited to capture techniques
utilizing horizontal faceplate surfaces. For example, Figs. 13-14 illustrate embodiments
in which a portion of the shell is captured between an exterior side surface of one
faceplate and an interior side surface of a second faceplate. In Fig. 13, a portion
1302 of shell 1301 is located, after assembly, between side 1303 of first faceplate
1305 and side 1307 of second faceplate 1309. Preferably a portion of shell 1301, for
example end portion 1311, is shaped to enhance the ability of the separate pieces
of the faceplate to capture and retain the shell. It will be appreciated that any
of a variety of shapes can be utilized (e.g., portion 1401 of Fig. 14) and that one
or more of the surfaces can be treated as disclosed above to enhance the ability of
the surfaces to grip the shell.
[0020] In yet another embodiment of the invention, the faceplate assembly comprises more
than two faceplate pieces. Additional faceplate pieces can be used to improve shell
retention and/or shell to faceplate sealing, reduce fabrication and assembly complexity,
or to simply provide cosmetic improvements (e.g., different coloured exterior faceplate
caps). Fig. 15 illustrates one such faceplate assembly 1500. As in previously illustrated
faceplate assemblies, assembly 1500 includes a first faceplate piece 1501 and a second
faceplate piece 1503 which are used to capture a portion of a shell 1505. This assembly
also includes a third faceplate member 1507 that is interposed between one surface
of shell 1505 and first faceplate piece 1501. It will be appreciated that member 1507
could also be interposed between shell 1505 and the second faceplate piece 1503 or
that a pair of members 1507 could be used, one interposed between a first side of
shell 1505 and faceplate piece 1501 and the second interposed between a second side
of shell 1505 and faceplate piece 1503. Preferably member 1505 comprises a material
that is suitable for sealing the shell to the faceplate assembly (e.g., elastomers,
silicones, latex, polyurethanes, or polyvinyls). In a preferred embodiment, shell
1501 is a rigid or semi-rigid shell and member 1505 is formed to fit tightly onto
the edge of faceplate piece 1501 (or alternately, faceplate piece 1503), typically
through the inclusion of mounting surfaces 1509 and 1511 in addition to sealing surface
1513.
[0021] In yet another embodiment of the invention, the faceplate assembly captures an intermediary
member which then, in turn, is coupled to the shell. For example, as shown in Fig.
16, a pair of faceplate pieces 1601 and 1603 capture an intermediary member 1605.
Any of the previously disclosed capture techniques can be used, including the use
of shaped retention members, compression techniques, etc. Attached to intermediary
member 1605, preferably after it has been coupled to the faceplate assembly, is shell
1607. In a preferred embodiment, shell 1607 comprises a flexible material (e.g., elastomers,
silicones, latex, polyurethanes, polyvinyls or polymers) and is preferably bonded
to member 1605 along a bond line 1609.
[0022] Another aspect of the invention is the means by which the first and second faceplate
pieces (e.g., upper and lower pieces) are coupled together, thereby capturing the
shell or intermediary member. For example, in the cross-sectional illustration of
Fig. 5, the upper and lower faceplate pieces are held together with one or more screws
525. In the perspective cross-sectional illustration of Fig. 6, the upper and lower
faceplate pieces are held together with one or more complementary, interlocking members
601. If such interlocking members are used, preferably during assembly the upper and
lower faceplate pieces are aligned and pressed together, causing the complementary
members to lock together, thereby capturing the shell as previously disclosed. Figs.
17-19 show three pairs, respectively, of interlocking members. Specifically, Fig.
17 illustrates an embodiment using interlocking barbs 1701 and 1703; Fig. 18 illustrates
an embodiment using a barb 1801 on one of the faceplate pieces with a lockable portion
1803 on the opposing faceplate piece; and Fig. 19 illustrates an embodiment using
complementary grooves 1901 and ridges 1903. It will be appreciated that these figures
are only meant to illustrate a few types of interlocking members that can be used
with the present invention. Other types of latches known by those familiar in the
art can also be used in the present invention. Additionally, it will be appreciated
that the upper and lower faceplate members can also be joined together using adhesives,
welding techniques (e.g., ultra-sonic welding), heat sealing, staking techniques (e.g.,
heat staking) or rivets.
[0023] Although many of the above-described embodiments recite a soft or compliant shell,
as previously noted the invention can also be used to fabricate hearing devices in
which the shell is rigid or semi-rigid. In this instance, one of the advantages of
the modular approach of the present invention over conventional assembly techniques
is the ability to easily disassemble a device for repair, adjustment or component
updating.
[0024] As will be understood by those familiar with the art, the present invention may be
embodied in other specific forms without departing from the spirit or essential characteristics
thereof. For example, the assembly techniques disclosed herein could be used for either
a wired or wireless earpiece for use with a telephone or other audio device. Accordingly,
the disclosures and descriptions herein are intended to be illustrative, but not limiting,
of the scope of the invention which is set forth in the following claims:
1. A modular hearing device comprising:
a shell;
a first faceplate piece;
a second faceplate piece; and
means for coupling said first and second faceplate pieces, wherein a portion of said
shell is captured between said first and second faceplate pieces when said first and
second faceplate pieces are coupled together.
2. A modular hearing device comprising:
a first faceplate;
a second faceplate coupleable to said first faceplate;
a shell having an open end with a shell edge portion; and
means for coupling said first and second faceplates, wherein said shell edge portion
extends between a first faceplate surface and a second, complementary faceplate surface.
3. The modular hearing device according to claim 2, wherein said shell edge portion further
comprises a shaped portion.
4. The modular hearing device according to claim 3, wherein said shaped portion is selected
from the group consisting of T-shapes, L-shapes, spherical shapes and irregular shapes.
5. The modular hearing device according to claim 3 or 4, wherein a faceplate assembly
cavity is formed by said first faceplate coupled to said second faceplate and wherein
at least a portion of said shaped portion resides within said faceplate assembly cavity.
6. The modular hearing device according to any of claims 2-5, wherein said shell edge
portion is compressed between said first faceplate surface and said second, complementary
faceplate surface.
7. The modular hearing device according to claim 6, wherein at least one of said first
faceplate surface, said second, complementary faceplate surface and said shell edge
portion is treated to enhance shell edge retention.
8. The modular hearing device according to claim 6, wherein at least one of said first
faceplate surface, said second, complementary faceplate surface and said shell edge
portion is roughened to enhance shell edge retention.
9. The modular hearing device according to claim 6, wherein at least one of said first
faceplate surface, said second, complementary faceplate surface and said shell edge
portion is coated to enhance shell edge retention.
10. The modular hearing device according to any of claims 2-9, wherein said coupling means
comprises at least one pair of complementary, interlockable members, wherein a first
interlockable member of said at least one pair of complementary, interlockable members
is coupled to said first faceplate and a second interlockable member of said at least
one pair of complementary, interlockable members is coupled to said second faceplate.
11. The modular hearing device according to any of claims 2-10, wherein said shell is
comprises a flexible material.
12. The modular hearing device according to claim 11, wherein said flexible material is
selected from the group of materials consisting of elastomers, silicones, latex, polyurethanes,
polyvinyls and polymers.
13. The modular hearing device according to any of claims 2-12, further comprising a third
faceplate member coupleable to said first faceplate.
14. The modular hearing device according to any of claims 2-13, further comprising a third
faceplate member interposed between said first faceplate and said shell edge portion.
15. A faceplate assembly for use with a hearing device, the faceplate assembly adapted
to a shell, the faceplate assembly comprising:
a first faceplate;
a second faceplate coupleable to said first faceplate; and
means for coupling said first and second faceplates to form said faceplate assembly,
wherein a portion of said shell is capturable by said faceplate assembly.
16. The faceplate assembly according to claim 15, wherein said coupling means comprises
at least one pair of complementary, interlockable members, wherein a first interlockable
member of said at least one pair of complementary, interlockable members is coupled
to said first faceplate and a second interlockable member of said at least one pair
of complementary, interlockable members is coupled to said second faceplate.