WO1997009864A1

WO1997009864A1 - Hearing aid with wax guard

Info

Publication number: WO1997009864A1
Application number: PCT/US1996/014225
Authority: WO
Inventors: James R. Newton
Original assignee: Argosy Electronics, Inc.
Priority date: 1995-09-05
Filing date: 1996-09-05
Publication date: 1997-03-13

Abstract

Disclosed is a hearing aid which has a cerumen guard comprised of a rigid porous plastic plug adjacent to the exterior surface of the hearing aid shell. The cerumen guards may be inserted into the receiver outlet, the microphone inlet, or the vents of the hearing aid. The rigid porous plastic has a hydrophobic characteristic, a multiplicity of interconnected pores effectively avoids the accumulation and clogging of inlets, outlets, and vents by cerumen while allowing transmission of sound. Use of sintered plastic beads provide for the rigidity of the porous plastic plug.

Description

HEARING AID WITH WAX GUARD BACKGROUND OF THE INVENTION

This invention relates to hearing aids, more particularly, it relates to devices to protect hearing aids from cerumen.

Hearing aids may be inserted in part or in the entirety into an individual's ear canal. The hearing aids necessarily have a sound output transducer commonly called a receiver and a outlet port for transmission of the sound output of the hearing aid to the user's ear canal to be sensed by the user's eardrum. An ongoing problem with the hearing aid receiver port is that they are susceptible to being plugged up with ear wax, also known as cerumen. This is especially a problem for modern completely-in-the-canal (CIC) and other miniaturized hearing aids. The clogging of the ports can significantly impair the operation of the hearing aid. When this happens, users will often attempt to clean or otherwise unplug the port often resulting in serious damage to the hearing aid receiver. The wax problem is responsible for millions of dollars of hearing aid repairs each year.

In addition, modern hearing aids also have venting extending through the length of the hearing aid. This venting has an inwardly directed port and an outwardly directed port . The venting ports are also subject to becoming clogged with cerumen.

Various means have been attempted to protect the hearing aid from accumulation and effects of wax but all have their drawbacks and are of varying effectiveness. For example, Patent No. 3,197,577 to Kuklock discloses baffles to form a serpentine or stepped aperture to prevent the ear wax from working all the way through to clog the acoustic output of the hearing aid receiver. This type of approach has been attempted in varying configurations but has the inherent problem of accumulation and ultimate buildup of wax which can still clog the acoustic output port and thus impair the operation of the hearing aid. Moreover, such means also present difficultly in cleaning and removal of the wax when it has built up.

U.S. Patent No. 4,553,627 to Gastmeier discloses a wax guard which has an acoustic filter but utilizes a cross passage intersecting the axial passage to prevent ear wax from entering the device. The acoustic filter is inserted in the axial passage. This patent anticipates the use of a cleaning tool to clear the cross passage. The device of Gastmeier utilizes a filter consisting of a layer of fabric and a layer of metal screen pressed into a tubing. It is apparent that this device is somewhat intricate and may be difficult or expensive to manufacture.

U.S. Patent No. 4,870,689 to Weiss again discloses the method of providing a tortuous route for the acoustic outlet port. It does not solve the problem of the accumulation of wax in the outlet port but provides a means of keeping wax away from the receiver component.

Patent No. 4,984,277 discloses a hearing aid which utilizes a replaceable filter element. The filter element has sound conduction openings, anticipates that periodic replacement is needed, and the invention is directed toward providing a user replaceable filter.

U.S. Patent No. 5,166,659 to Navarro discloses a hearing aid which utilizes a barrier to deflect wax when the hearing aid is inserted to prevent clogging of the receiver outlet port.

All of the prior art devices for preventing clogging of the receiver outlet port present disadvantages such as the need for periodic replacement, difficultly in cleaning accumulated wax, incapability of use on existing heaing aids, and intricate or complicated design. SUMMARY OF THE INVENTION

Disclosed is a hearing aid which has a cerumen guard comprised of a rigid porous plastic plug adjacent to the exterior surface of the hearing aid shell . The cerumen guards may be inserted into the receiver outlet, the microphone inlet, or the vents of the hearing aid. The rigid porous plastic has a hydrophobic characteristic, a multiplicity of interconnected pores effectively avoids the accumulation and clogging of inlets, outlets, and vents by cerumen while allowing transmission of sound. Use of sintered plastic beads provide for the rigidity of the porous plastic plug.

An object of the invention is to provide guards to prevent the clogging of ports or vents in hearing aids by wax.

A feature and advantage of the invention is that the wax guards are reliable, may be easily cleaned by the user, and if necessary, may be easily replaced.

A feature of the invention is to provide a porous wax guard that repels cerumen.

A further feature and advantage of the invention is to provide an effective receiver wax guard which may be easily retrofitted into existing hearing aids.

A further feature of the invention is to provide an effective receiver wax guard which is inexpensive to manufacture and install while still providing excellent sound transmission characteristics through the guard.

A further feature of the invention is to provide a wax guard which may be utilized in existing hearing aid configurations. Existing hearing aids utilize a flexible tube extending to a port in the housing. Such hearing aids may utilize the invention by insertion of an appropriately sized plug into the end of the tube at such port. This solution to the cerumen problem requires minimal or no modifications to current manufacturing processes for hearing aids and allows post production and field installation and replacement.

A further feature and advantage of the invention is that the wax guard does not need to increase the size of the hearing aid in that it may be inserted in its entirety into a port of the hearing aid.

A further feature and advantage of the invention is to provide a guard at hearing aid ports which is hydrophobic and resists accumulation and clogging with cerumen and persperation.

A further feature and advantage of the invention is to provide a wax guard which may be easily cleaning of wax without risk of damaging the receiver or microphone. The wax guard can be cleaned with fluid and without removal from the hearing aid. Moreover, the color of the wax guard gives a visual indication of the amount of the degree of accumulation of cerumen and contaminants.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a elevational view of a CIC hearing aid with a wax guard and with a section of the housing cut away.

FIG. 2 is a cross-sectional view taken at line 2-2 of FIG. 1 showing tubing with a wax guard in place and connected to the hearing aid receiver.

FIG. 3 is a detail view of a hearing aid wax guard pursuant to the invention showing the porosity of the plastic, FIG. 4 is an end view of the hearing aid of FIG. 1 showing a microphone inlet port and a vent .

FIG. 5 is an end view opposite of FIG. 4 of the hearing aid showing a receiver outlet port and a vent .

FIG. 6 is a sectional view taken at line 6-6 of FIG. 4 showing a wax guard in a vent.

FIG. 7 is a partial sectional view of a different style hearing aid with wax guards.

FIG. 8 is a perspective view of foam pads illustrating a process for cleaning the wax guard.

DETAILED SPECIFICATION

Referring to FIG. 1, a partial sectional view of a hearing aid utilizing porous plastic for a wax guard is shown. The hearing aid, generally indicated by the numeral 9, is comprised principally of a housing 10, a microphone 12, a sound transducer or receiver 14, circuitry 16, and a wax guard 17. The circuitry 16 includes a hybrid module 20 along with associated wiring 22 for connection of the various components. The circuitry is powered by a battery 26 which is held into the hearing aid by a battery casing 28 and accessed through a battery latch 29. The receiver 14 has an output end 32 which is engaged with a silicon tubing 34, as better shown in FIG. 2. The flexible silicon tubing 34 adjoins the end 35 of the housing 10 at the outlet port 40 of the hearing aid and may be sealed with silicon 36. The tubing 34 has a bore 44 suitably sized for "slide-on" engagement with the receiver output end 32. Tubing 34 has a first end 46 and a second end 48 with the first end engaged with the receiver output end 32 and the second end 48 adjoining the hearing aid housing 10. The second end of the tubing 48 forms part of the outlet port 40 located at the inwardly facing end 54 of the hearing aid. Alternatively, wax guard 17 could be adhered to the housing 10 with the tubing 34 secured to the guard 17.

The hearing aid housing may be formed of acrylic material and also includes a face plate 60 which adjoins the shell portion 62 of the housing 10, an outer surface 61, and an inner surface 63. The ace plate 60 is thus at the outer end 64 of the hearing aid. Extending through the hearing aid is venting 72 which is comprised of a venting port or a first vent 75 through face plate 60 and a second vent 76 or venting port at the outer end. Each of the ports extend from the interior 77 of the hearing aid 9 to the exterior 79. The outlet port 40, the microphone inlet port 80, the first vent 75 and second vent 76 have porous plastic members configured as plugs 17, 84, 86, 90 and functioning as wax guards. The plugs 86, 84 on the outer end of the hearing aid can also function to prevent debris, such as dandruff, or matter, such as moisture, from entering the hearing aid 9.

Referring to FIG. 3, such a plug is shown in detail with joined spheres or beads 93 creating a multiplicity of pores 91 forming the porosity of the plastic. The porosity is such that the pores communicate with each other. Such a porosity provides for passage of gases and acoustic signals but inhibits or prohibits the entrance of cerumen or other debris or matter into the hearing aid.

Structural rigidity is provided by forming the porous plastic by joining plastic beads such as by sintering. This provides greatly increased rigidity over traditional spongy foamed porous plastic formed by gas injection or chemical reaction. The sintered bead plug is formed by introducing plastic beads into a mold, providing suitable pressure and temperature for a suitable period of time to adhere or weld the beads together without destroying the porosity. The sintered beads provide greater strength, less compressibility, higher density, and greater rigidity than foamed plastics.

Bead diameter of .005 to .020 inches have been found to provide plugs with the desired characteristics.

Although various porous plastics would be suitable for these applications, it has been found that porous high density polyethylene performs quite well. Porous polyethylene is rigid and structurally strong. Such polyethylene material and other suitable porous plastics are available from Interflow Technology, 19 Clay Street, Brooklyn, New York 11222.

In FIGS. 4 and 5, end views of the hearing aid are shown. FIG. 4 shows the face plate 60 of the hearing aid with the battery latch 29, the microphone inlet port 80, and the vent 75.

Referring to FIG. 7, an alternate configuration of an "in-the-ear" type of hearing aid is shown. As with the CIC hearing aid shown in FIG. 1, this hearing aid has the principal components of the housing 10, the microphone 12, the receiver 14, the circuitry 16, and the battery 26. The microphone 12 has an inlet port 80 and an inlet tube 95. This hearing aid also has venting 72 comprised of a channel 73 in the interior 77 extending through the hearing aid, a first vent 75, and a second vent 76. The second vent 76 has a porous plastic plug 98 while the first vent 75 in this hearing aid does not have a plug in that the outer end 64 of this style hearing aid is not typically subject to cerumen clogging. However, such a plug could be utilized in the venting port 75, as shown in FIG. 1, to prevent entrance of matter such as moisture or dust. The outlet port 40 of the hearing aid of FIG. 7 also has a porous plastic wax guard 100 inserted in the outlet tube 102 of the receiver 14. In this embodiment the outlet tube 102 is shown directly attached to the housing 10 of the hearing aid and the wax guard 100 is inserted into said receiver outlet tube 102 and thus is also inserted into the outlet port 40.

Porous plug 82 may be inserted and affixed into the tubing 34 at the outlet port 40 and secured in place by way of an interference fit whereby the flexible tubing provides a radial compressive gripping force on the rigid plug. Alternatively, the plug may be held in place such as by a cyanoacrylate adhesive particularly where the plug directly contacts a rigid housing such as a vent plug 86 as shown in FIG. 6. The porous plug 82 suitably has a median pore size of 100 micrometers.

The plugs 84, 90 positioned in the venting 80 of the hearing aid 9 may suitably have a porosity less what is used in the microphone and receiver ports, in that ideal sound transmission characteristics are not needed.

Generally porous plastics, particularly polyethylene, have a hydrophobic characteristic which appears to be very effective for repelling and avoiding the wicking or adsorption of any wax within the porous plastic, Thus, the hydrophobic tendency of the porous plastic provides a significant advantage which is not available for wax guards traps or filters of other types of materials or different configurations. This repellant tendency minimizes wax accumulation at the vents and ports and, if wax does accumulate, it may be easily cleaned or removed by brushing the wax away or, if necessary, by use of peroxide or suitable commercial earwax removal solution. Referring to FIG. 8, the hearing aid configuration with the plug at the exterior of the hearing aid housing permits use of a dual pad system for cleaning the wax guard. A first foam pad 112 is moistened with cleaning fluid 114 to create a dampened spot 116 such that the pad 114 absorbs the fluid. The end of the hearing aid 9 with the wax guard 17 is gently rubbed on the dampened spot with a circular motion to wick the cleaning fluid into the porous plug. The hearing aid and plug is then blotted and rubbed on the dry second foam pad 120. The process is repeated until the cerumen guard is clean. Where the porous plastic of the wax guard has an initial color, such as white, that contrasts with the color of the wax guard with accumulated cerumen, the cleaning process may be repeated until the wax guard returns to its original color thus providing a reliable indicator that the wax guard is adequately cleaned.

Although high density polyethylene formed in a porous plastic plug has proved to be quite suitable for the wax guard application, other types of plastics are anticipated to also be usable in this application and would be included in the invention. Such plastics would include low density polyethylene, ethylene vinyl acetate, ultra-high molecular weight polyethylene, polypropylene, polyester, polyamids/nylons, polysulfone, polyvinylidine fluoride, polytetraflurorethylene/teflon.

A suitable size for the porous plastic plug 17 inserted into the receiver outlet port 40 is .062 inch diameter with a .062 inch length. Such a configured plug provides excellent sound transmission characteristics and is also large enough to easily handle and to reliably secure within the outlet port.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Claims

IN THE CLAIMS;

1. A hearing aid with wax protection, the hearing aid comprising:

a) a housing with an exterior surface;

b) a microphone for generating electrical signals from sound, the microphone contained by the housing;

c) circuitry configured to condition the electrical signals, the circuitry connected to the microphone and contained in the housing;

d) a power source for the circuitry;

e) a transducer for producing a sound output, the transducer contained in the hearing aid housing and connected to the circuitry, the hearing aid having an outlet port through which the sound output exits the hearing aid; and

f) a porous cylindrical plug formed of sintered plastic beads fixed in the outlet port for protection of the transducer from cerumen.

2. The hearing aid of claim 1, wherein the outlet port is comprised of flexible tubing engaged with the transducer, said tubing exposed to the exterior of the housing, and wherein the plastic plug is affixed inside of said tubing and adjacent the exterior surface of the housing.

3. The hearing aid of claim 1, wherein the plastic plug is formed of polyethylene beads.

4. The hearing aid of claim 1, wherein the plastic beads have an average diameter within the range of .005 to .020 inches.

5. The hearing aid of claim 2, wherein the cylindrical plug is retained in the flexible tubing by an interference fit .

6. The hearing aid of claim 5, wherein the plastic plug is positioned at the exterior surface of the hearing aid housing.

7. The hearing aid of claim 1, wherein the microphone has an inlet port for receiving sound, and wherein the hearing aid is further comprised of an inlet guard comprised of porous plastic fixed in the inlet port.

8. The hearing aid of claim 1, wherein the housing has an inward end facing toward a user's ear drum and an opposite outer end, wherein the hearing aid has venting from the inward end to the opposite outer end, and wherein the hearing aid is further comprised of a wax guard comprised of porous plastic inserted in said venting.

9. A hearing aid with a wax guard, the hearing aid having a housing with an interior area, an exterior, and a port communicating between the interior and the exterior of the hearing aid, the guard comprised of a porous cylindrical plug with interconnecting pores formed of joined beads, the guard positioned at the exterior of the hearing aid in said port, whereby entrance of matter into the interior of the hearing aid is prevented.

10. The hearing aid of claim 9, wherein the hearing aid is further comprised of an output transducer and the port of the hearing aid communicates with said output transducer, and wherein the guard extends into said port.

11. The hearing aid of claim 10, wherein the output transducer communicates with the port by flexible tubing and wherein the guard is retained in the tubing by the tubing radially gripping the guard.

12. The hearing aid of claim 11, wherein the joined beads are polypropylene.

13. The hearing aid of claim 9, wherein the hearing aid is further comprised of a microphone with an inlet, the inlet connected to the port.

14. A hearing aid with wax protection, the hearing aid comprising:

a) a housing with an exterior surface;

d) a power source for the circuitry;

e) a transducer for producing a sound output, the transducer contained in the hearing aid housing and connected to the circuitry;

f) flexible tubing connected to the transducer and extending exterior to the housing at an outlet port; and

g) a rigid porous cylindrical plug retained within the flexible tubing by an interference fit within the tubing, the plug extending to be adjacent the exterior surface of the housing.

15. The hearing aid of claim 14, wherein the porous cylindrical plug is formed of plastic beads adhered together.

16. The hearing aid of claim 15, wherein the plastic beads are adhered together by sintering.