Press-fit ear wax barrier

An ear wax barrier for an in-the-ear or in-the-canal type hearing aid device positioned at least in part between a receiver output port and a shell acoustic output port includes a substantially cylindrical housing having a barbed portion for press-fitting the barrier into position. The barrier may include a screen and/or a plurality of undulations, such as a thread internal thereto for providing wax accumulation sites to retard the migration of wax into the hearing aid. The barrier is more easily inserted than removed.

FIELD OF THE INVENTION 
This invention pertains to ear wax barriers for hearing aids. More 
particularly, this invention pertains to press-fit ear wax barriers for 
in-the-ear and in-the-canal type hearing aids. 
BACKGROUND OF THE INVENTION 
In-the-ear and in-the-canal type hearing aids have become accepted by the 
hearing impaired public for their small size, ease of use and relative 
comfort, as compared to older style hearing aids. Many of the in-the-ear 
and in-the-canal type devices include a shell which is designed to fit in 
the ear or ear canal of the user. 
The shell may hold the electronic circuitry, a microphone, and a receiver. 
The microphone receives sound signals from outside of the device and 
responsively creates an electronic signal. The signal may be sent to an 
amplifying circuit which supplies a signal to the receiver. The receiver 
in turn, provides audio output to the ear. 
Typically, in the in-the-ear and in-the-canal type devices, sound travels 
from an output port of the receiver, through a sound channel, and out of 
the device through an acoustical output port in the hearing aid shell. The 
sound may then travel through the user's ear and cause the tympanic 
membrane to vibrate. 
The ears secrete a substance known as cerumen or ear wax. While ear wax 
cleans the internal structure of the ear, it also tends to flow into the 
sound channel and receiver of a hearing aid located in the ear. Ear wax 
which migrates into a hearing aid can degrade the effectiveness of the 
device and can eventually cause the device to fail. 
A number of barrier products are presently available to prevent or reduce 
the migration of ear wax into a hearing aid. One such barrier design uses 
a fine mesh screen in the sound channel between the receiver and 
acoustical output port of the shell. While such a barrier reduces the 
migration of ear wax into the hearing aid, it suffers from the possibility 
of becoming clogged with wax. 
More recently, barrier systems have been introduced which include a housing 
which threadedly interconnects the output port of the receiver and the 
acoustic port of the shell. The housing threads into a portion of the 
shell. The housing has an interior surface which includes projections 
extending inwardly thereof, creating a tortuous path for solid or 
semi-liquid ear wax migrating therethrough. 
Such devices are disclosed in Weiss, U.S. Pat. No. 4,870,689, entitled "Ear 
Wax Barrier For A Hearing Aid" and Weiss et al., U.S. Pat. No. 4,972,488, 
entitled "Ear Wax Barrier And Acoustic Attenuator For A Hearing Aid," both 
of which patents are commonly assigned herewith, and both of which patents 
are hereby incorporated by reference. 
In the devices disclosed in the Weiss and Weiss et al. patents, the barrier 
is incorporated into a housing, which has projections extending inward of 
the housing. The barrier is then threaded into the hearing aid shell. This 
design was a significant improvement over devices prior thereto. 
Nevertheless, threading the barrier to the hearing aid requires additional 
mechanical components or alteration of the shell to effect the attachment. 
Thus, there continues to be a need for hearing aid ear wax barriers which 
are easily inserted and removed without additional mechanical components 
and/or shell alterations. Preferably, such barriers would also provide an 
effective configuration for preventing the migration of ear wax into the 
hearing aid. 
SUMMARY OF THE INVENTION 
A press-fit ear wax barrier is provided for use with in-the-ear or 
in-the-canal type hearing aids. The hearing aid includes a shell with an 
acoustical output port and a receiver having a receiver output port 
positioned within the shell. 
The barrier includes a housing which is adapted to be received at least 
partially intermediate the acoustical output port and the receiver output 
port. The housing includes a central acoustical passageway linking the 
acoustical output port and the receiver output port. 
A mesh barrier element can be carried by the housing to impede the flow of 
ear wax into the acoustic passageway. Alternately, a plurality of 
undulations may extend inwardly of, and cooperate to occlude wax movement 
through, the acoustical passageway. 
The undulations define traps or wax accumulation sites within the barrier. 
The accumulation sites retard migration of ear wax into the hearing aid. 
The barrier also includes an exterior wall surface which has a 
substantially cylindrical portion having a predetermined diameter. A 
frusto-conical barb is located on an exterior end of the housing. The barb 
has a base area diameter which is larger than the diameter of the 
cylindrical portion. The barb permits press-fitting the barrier into a 
position at least partially intermediate the acoustical output port and 
the receiver output port. 
In another aspect of the invention, the barrier undulations can be formed 
by a thread within the central acoustical passageway. The thread may be 
continuous or may be formed in discrete sections. 
In one embodiment, the barrier includes a collar portion having a diameter 
greater than the diameter of the cylindrical portion to prevent 
over-insertion of the barrier. The collar portion may include a recessed 
area for receiving, for example, an attenuator screen. 
In another embodiment, the housing serves as a press-fit connector to 
releasably couple, for example, the receiver output port to a receiver 
tube or channel, positioned between the receiver and the hearing aid 
shell. A press-fit wax guard of the type described above can be used in 
combination with the releasable receiver connector. 
In yet another aspect of the invention, the structure can also function as 
an acoustic attenuator. 
Other features and advantages of the present invention will be apparent 
from the following detailed description, the accompanying drawings, and 
the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
While the present invention is susceptible of embodiment in various forms, 
there is shown in the drawings and will hereinafter be described preferred 
embodiments with the understanding that the present disclosure is to be 
considered an exemplification of the invention and is not intended to 
limit the invention to the specific embodiments illustrated. 
FIG. 1 illustrates an in-the-ear type hearing aid 10 positioned in the ear 
canal C of a user. It will be understood that the following comments also 
apply to in-the-canal type hearing aids. 
As best seen in FIG. 2, the hearing aid 10 includes a shell 12, which 
supports or encloses a microphone 14, amplification circuitry (not shown) 
and a receiver 16. 
The shell 12 and receiver 16 each include an acoustic output port 18 and 
20, respectively. In a typical arrangement, sounds from outside of the 
hearing aid 10 are received at the microphone 14. The microphone 14 
converts the sound into an electrical signal which is amplified in the 
amplification circuitry. 
A responsive electrical signal is transmitted by the amplification 
circuitry to the receiver 16 which, in turn, creates an audio output. The 
audio output is transmitted from the receiver output port 20, via a 
receiver tube or channel 22 to the shell output port 18. The sound output 
may then be received at, and vibrate, the user's tympanic membrane, 
creating distinguishable sounds. 
In one embodiment of the present invention, illustrated in FIG. 3, the 
receiver tube 22 interconnects the receiver 16 and the shell 12. The tube 
22 penetrates the shell 12 at a location of the shell 12 which is 
positioned in the ear canal C. An ear wax barrier 24 is positioned in the 
tube 22 at a distal most portion 26 thereof. 
Referring now to FIG. 3a, the barrier 24 includes a housing 30, a collar 
portion 32, and a barb 34. The housing 30 is cylindrical and includes a 
substantially cylindrical, central acoustical passageway 36 therethrough. 
The passageway provides acoustical communication between the receiver 
output port 20 and the shell output port 18. 
The collar 32 which is located at a distal end 38 of the housing 30 has a 
larger diameter than the housing 30. The collar 32 prevents over-insertion 
of the barrier 24 into the tube 22. The collar may also include a 
recessed, preferably circular area, shown generally at 40, for receiving, 
for example, a barrier screen 42. In an alternate configuration, a barrier 
screen 42' may be positioned internal to the barrier 24, at a location 
approximately corresponding to the barb 34. 
The size and number of openings in the screens 42, 42' may be varied as 
would be understood by those of skill in the art. The screens 42, 42' may 
also function as attenuators. 
The barb 34 is located distally of the collar 32, and has a generally 
frusto-conical shape. The barb 34 surrounds the housing 30 and tapers to a 
diameter about equal to the inner diameter d.sub.I of the housing 30. The 
widest portion 46 of the barb 34, which is at a base portion 48 thereof, 
has a diameter d.sub.w larger than an outer diameter d.sub.0 of the 
housing 30. A lip 50 is formed at the juncture, shown generally at 52, of 
the barb's widest portion 46 and the housing 30. 
As shown in FIG. 4, the barrier 24 can be readily inserted, or 
press-fitted, without rotation, into the tube 22, without interference 
from the barb 34. The barrier 24, however, resists removal or dislodging 
by the frictional engagement of the lip 50 with the tube 22. 
FIGS. 5 and 5a illustrate an alternate embodiment 124 which can function 
only as a connector or as a connector/barrier. The element 124 is 
collar-less. In the illustrated configuration, the element 124 is 
positioned adjacent to the receiver 16. In this arrangement, the element 
124 is positioned on the receiver 16 at the receiver output port 20. The 
element 124 couples the receiver 16 to the receiver tube 22. 
The element 124 could be integrally formed as a part of the output port 20, 
with or without a barrier screen such as 142. Alternately, the element 124 
may be glued to the receiver output port 20. 
The element 124 is positioned such that the barb 134 is directed away from 
the receiver 16, into the tube 22. This configuration makes it possible to 
releasably couple the receiver 16 to the audio output tube 22. 
Another arrangement for mounting the element 124, is shown in FIG. 6. In 
this configuration, the element 124 is positioned in the tube 22 with the 
barb 134 directed toward the receiver 16. The element 124 can function as 
an attenuator or a wax guard in this configuration. 
However, unlike the arrangement illustrated in FIGS. 5 and 5a, the element 
124 shown in FIG. 6 is positioned at an intermediate portion 54 of the 
tube 22, between the receiver output port 20 and the shell output port 18. 
In this configuration, the tube 22 is mounted to the receiver 16, by 
methods which will be readily recognized by those skilled in the art, or 
as will be described later. 
As shown in FIG. 7, the collar-less element 124 can include a recessed area 
140 which is adapted to receive, for example, a barrier or attenuator 
screen 142, or like device. Alternately, a barrier or attenuator screen 
142' may be positioned internal to the element 124, at a location 
approximately corresponding to the barb 134. 
FIGS. 8-13 illustrate various embodiments of barriers in accordance with 
the principles of the present invention. FIG. 8 shows an embodiment 224 of 
the barrier having a housing 230, a collar portion 232, and a barb 234. 
The housing 230 defines a substantially cylindrical, central passageway 
236 therethrough, which provides acoustical communication between the 
receiver output port 20 and the shell output port 18. 
The embodiment illustrated in FIG. 8 includes the recessed area 240 at the 
collar portion 232, the juncture of which defines a first shoulder 256. A 
second shoulder 258 is formed internal to the housing 230 at a location 
which approximately corresponds to the widest portion of the barb 246. 
The barrier 224 includes a plurality of undulations, shown as a thread 260, 
formed in the interior surface 262 thereof. The thread 260 is formed of a 
root 260a and a crest 260b, and creates a tortuous path for the migration 
of ear wax into the hearing aid 10. Essentially, the thread 260 defines 
traps by providing wax accumulation sites along the root 260a and the 
crest 260b, as well as across the thread 260. 
The thread 260 may be formed in a continuous manner; alternately, the 
thread 260 may be formed in discrete sections. The thread 260 may also be 
formed as ridges (not shown) along the interior surface 262 of the housing 
230. 
In a preferred embodiment, the thread 260 extends between the first 
shoulder 256 and the second shoulder 258. The barrier 224 may also 
include, as previously discussed, a barrier screen 242. The screen 242 
extends across the passageway 236, and may be positioned on either the 
first or second shoulder 256 or 258, respectively. 
An alternate embodiment 324 is shown in FIG. 9. The barrier 324 is similar 
to that shown in FIG. 8, and includes, a housing 330, a collar portion 
332, and a barb 334. The housing 330 defines a substantially cylindrical, 
central passageway 336 therethrough, which provides acoustical 
communication between the receiver output port 20 and the shell output 
port 18. 
The embodiment 324 of the barrier illustrated in FIG. 9, includes the 
shoulder 358 internal to the housing 330, approximately positioned to 
correspond to the widest portion 346 of the barb 334. A thread 360 similar 
to that formed in the embodiment shown in FIG. 8, extends from about the 
collar 332 to the shoulder 358. 
The embodiment shown in FIG. 9, however, does not include a recessed area 
at the collar portion 332. Rather, a barrier screen 342, if used, can be 
positioned across the shoulder 358. Alternately, the screen can be affixed 
to the barrier, at the proximal end 344 of the housing 330 adjacent to the 
barb 334. 
Another embodiment 424 is illustrated in FIGS. 10 and 10a. In this 
embodiment, upper and lower projections 464 and 466 extend inwardly of the 
barrier 424 opposing each other. The projections 464, 466 occlude the 
passageway 436 creating a tortuous path for the migration of ear wax. The 
projections 464, 466 terminate in ends 468 and 470, respectively. A rib 
474 extends between the terminal ends 468 and 470, and provides additional 
wax accumulation sites. 
FIG. 11 shows an embodiment similar to that shown in FIGS. 10 and 10a. This 
embodiment of the barrier 524 incorporates a plurality of ribs 574a-c, 
extending between terminal ends 568 and 570, thus providing further wax 
accumulation sites. 
Still another embodiment 624 is shown in FIG. 12. The barrier 624 includes 
upper and lower projections 676 and 678, respectively, which extend 
inwardly of the barrier 624, and which occlude the passageway 636. Each of 
the projections 676 and 678 includes an upwardly extending flange portion 
680, 682, respectively. The projections 676, 678, and flanges 680, 682, 
define trap means by providing wax accumulation sites 684 and 686, 
thereon. 
Another embodiment 724 is shown in FIG. 13. This embodiment includes a barb 
734 and a collar portion 732 on opposing sides of a housing 730. The 
housing 730 defines an uninterrupted central acoustical passageway 736 
therethrough. 
The barrier includes a barrier screen 742 positioned internal to the 
passageway 736, at a location approximately corresponding to the barb 734. 
In this embodiment of the barrier 724, the screen 742 is curved or formed 
concave relative to the barb 734. Other curved or non-planar arrangements 
are also possible. 
As shown in FIG. 14, one form 824 of the element may be used as a 
connector. The connector 824 may be mounted to, for example, a receiver 
output port 20, such as by gluing. 
One end of a receiver tube or channel 22 may be connected to the barbed end 
834 of the connector 824 to effect the connection. The other end of the 
tube 22 may be connected to a barrier (shown at 24) mounted to the tube 22 
at the hearing aid shell 12. 
FIG. 15 illustrates an alternate configuration. A connector 824 is mounted 
to the receiver output port 20. One end of the tube or channel 22 is 
mounted to the connector 824. The other end of the tube 22 is connected to 
a barrier 24 mounted to the tube 22 at the hearing aid shell 12. 
An in-line attenuator 924 is positioned in the tube 22 intermediate the 
barrier 24 and the connector 824. The attenuator 924 may reduce or 
eliminate feedback or oscillations, or may smooth the frequency response 
characteristics in the hearing aid 10 circuitry. 
The attenuator 924 may include a perforated member, such as a screen 942. 
The screen 942 perforations may be varied to produce differing attenuation 
characteristics. 
As shown in FIG. 16, one embodiment 1010 of a modular hearing aid includes 
a shell 1012 and a modular, removable circuit portion 1014. The circuit 
portion 1014 includes a mounting plate 1016, which may serve as an outer 
part of the hearing aid shell 1012. The plate 1016 is attached to the 
shell 1012 in normal operation. 
The mounting plate 1016 may carry a receiver 1018 and amplification 
circuitry 1019 coupled thereto. A microphone 1020 and a battery 1022 are 
carried on the plate 1016 and are coupled to the circuitry 1019. The 
receiver 1018 has a barbed connector 824, such as the connector shown in 
FIG. 14, attached to a receiver output port 1026. 
The shell 1012 includes a tube or channel 1028 mounted thereto. A barrier 
1024, exemplary of which is the barrier illustrated in FIG. 3, is mounted 
to the tube 1028, at the shell 1012. 
The modular circuit portion 1014 can be mounted to the shell 1012 with the 
connector 824 press-fitted to the tube 1028. This configuration permits 
easy separation of the shell 1012 from the circuit portion 1014 to 
facilitate maintenance of the hearing aid 1010. This configuration also 
permits replacement of the circuit portion 1014, without necessarily 
replacing or manufacturing a custom shell 1012. 
Thus, ear wax barriers 24, 124, 224, 324, 424, 524, 624, 724 and 824 are 
disclosed for use with in-the-ear and in-the-canal type hearing aids 10, 
1010. The barriers 24, 124, 224, 324, 424, 524, 624, 724 and 824 are 
readily adaptable to such hearing aids 10, 1010 without additional 
mechanical components or alterations in the hearing aid shell. The 
barriers 24, 124, 224, 324, 424, 524, 624, 724 and 824 resist ear wax 
migration by providing a tortuous path for solid or semi-liquid ear wax 
which secretes from the ear canal C and tends to clog or cause failure of 
such hearing aids 10, 1010. 
From the foregoing it will be observed that numerous modifications and 
variations can be effectuated without departing from the true spirit and 
scope of the novel concepts of the present invention. It is to be 
understood that no limitation with respect to the specific embodiments 
illustrated is intended or should be inferred. The disclosure is intended 
to cover by the appended claims all such modifications as fall within the 
scope of the claims.