US2535258A - Earpiece with inflatable sealing means - Google Patents

Description

Dec. 26, 1950 R. B. BLAND 2,535,258

EARPIECE WITH INFLATABLE SEALING MEANS Filed Dec. 5, 1947 IN VEN TOR.

w g ww Patented Dec. 26, 1 950 EARPIECE WITH INFLATABLE SEALING ANS Reginald B, Bland, Newport News, Va.

Application December 5, 1947, Serial No. 790,002

Claims.

This invention relates to ear pieces for audiphone receivers and more particularly to the ear tip or portion of the ear piece adapted to enter the auditory canal of the ear.

In modern audiphone practice an amplifier of either the microphone or vacuum tube type is ordinarily used between the transmitter and receiver and since the gain used at times may be as much as 50 decibels or more, special precautions must be taken to avoid singing due to acoustic or other coupling between the output and input circuits. This is true even though the pickup transmitter is mounted on some part of the body relatively remote from the receiver. The problem of singing becomes even more acute when an attempt is made to mount the pickup transmitter and the receiver in a single casing as where the transmitter and receiver are integrated into a single unit to be carried at the ear of the user. Even though an integrated transmitter and receiver combination wa suggestedras far back as 1912 as shown in the patent to Soret No. 1,154,069 and though many advantages result from having the pickup transmitter and receiver mounted in a single casing near the ear of the user, the use of such integrated transmitter, receiver audiphone units, particularly where the acoustic gain desired is high, has been largely prevented due to this acoustic coupling between the pickup transmitter and the receiver commonly referred to as feedback.

Acoustic feedback, which is characterized by the presence of a continuous whistling sound of more or less fixed pitch, results as a consequence of the introduction of exciting forces on the diaphragm or pressure sensitive element of the transmitter which are translated into fluctuating electric currents, amplified, caused to vibrate the diaphragm of the receiver, and are thereby converted back, in whole or in part, into exciting forces on the transmitter diaphragm. An unstable condition then exists and the exciting forces build up until the amplifier is overloaded and further increase becomes impossible.

One of the primary sources whereby vibrations of the receiver diaphragm are converted back into exciting forces picked up by the transmitter is through an air path due to leakage between the ear piece of the receiver and the auditory canal. Ear pieces as commonly used are made of rigid and inflexible material while the size and shape of the ear canal changes from day to day and hour to hour with the individualperson. Thus the ear piece may be uncomfortably tight in the morning and loose at night. Pulling on the lobe of the ear, or pressing on the skin of the adjacent check, as by lying on a pillow; or resting the head on the hands will change the shape of the canal from approximately circular to oval, thus permitting the sound waves inside the canal to gain egress to the outside air and hence to the transmitter. In fitting hearing aids it is well known that the higher "the acoustic gain required to bring the sound intensity up to a level that will be audible to a person hard of hearing the tighter the fit must be between the ear piece and the auditory canal. Where a person is particularly hard of hearing often nothing can be done for him since it is impossible, with known ear pieces, to obtain the necessary seal between the ear piece and the ear canal for the high acoustic gains required so that for such people wearing a hearin aid results only in a continual and high pitched whistling sound.

It is therefore the primary object of my invention to provide an ear piece for audiphone receivers in which the ear tip, or portion of the ear piece adapted to enter the auditory canal of the ear, once fitted to the ear of the user will automatically adjust itself to changes in the size and shape of the ear canal so as to provide a satisfactory seal between the ear tip and canal at all times when in use.

It is a further object to provide an ear tip which can be adjusted to fit ear canals of various sizes and in varying degrees of tightness so that the pressure exerted by the ear tip on the sides of the canal can be carefully adjusted by the one fitting the hearing aid so as to provide a satisfactory seal and, at the same time, a seal that will not be uncomfortably tight,

Other objects and advantages of the invention will be apparent on study of the following description of a preferred embodiment of the invention in conjunction with the appended drawings in which,

Figure 1 is a perspective view of an audiphone receiver and attached ear piece, the ear piece being formed in accordance with the present invention;

Figure 2 is a side view of a portion of the ear piece showing the ear tip in cross section; and

Figure 3 is an enlarged detail sectional view of the inflatable hollow torus carried by the ear tip.

Referring to the drawings, numeral 1 indicates generally the receiver unit or an integrated transmitter receiver unit of an audiphone which} has attached thereto an ear piece 2 having a portion 3 molded to fit the concha of the ear and an ear tip 4 adapted to enter the auditory canal of the ear. The molded portion 3 and the ear tip 4 serve to hold the receiver and. ear piece securely in place in the users ear. The ear tip 4 is provided with an air passage 5 therethrough which is in communication with the receiver 1 and serves to transmit sound vibrations from the receiver l into the auditory canal of the ear.

In order to obtain a tight seal between the ear canal and the ear tip 4 to prevent air leakage therebetween which might result in feedback of the sound pulses to the pickup transmitter, an inflated flexible, hollow torus 6 is provided which is fitted securely to the ear tip. As shown in the drawings the torus 6 comprises a flat base section 1 and an arcuate top section 8. The respective edges of the section 1 and 8 are secured to each other by the use of a suitable adhesive or other means to prevent any leakage of fluid therebetween. In the preferred modification both the base section '5 and the arcuate top section 8 are made of rubber, the arcuate top section 8 being formed of a self-sealing rubber material through which a hollow needle 9, such as that of a small hypodermic needle, may be inserted to force air or some liquid such as alcohol between the sections 1 and 8 to inflate the torus to the desired size. in a groove It formed around the outer periphery of the ear tip 4 the groove lil being of such depth that the edges of the torus 6 are substantially flush with the outer periphery of the ear tip 4.

Care should be taken when fitting the torus 6 to a the ear tip 4 that there is no leakage path between the torus and the ear tip. This can be prevented by providing a tight fit between the torus and the ear tip or by the use of some sealing material such as a rubber or other cement.

When fitting the ear piece to the customer, the fitter inserts the needle 9 of a syringe or like instrument ll through the self-sealing material of the inflatable torus 6 and injects air or a liquid such as alcohol into the interior of the torus until the torus is inflated enough to provide a sufficiently tight seal to prevent feedback at the amplification necessary in the particular instance and yet at the same time not to have the seal so tight as to cause uncomfortable pressure on the sensitive inner walls of the ear canal of the user.

It is obvious that if the ear tip is formed to fit too tightly after being inflated a portion of the inflating fluid can be removed in the same manner in which it is injected into the inflatable torus, thus enabling the fitter to provide a considerably more satisfactory fit than can be obtained with present known ear pieces. Due to the adjustability of ear pieces embodying the present invention, the necessity of carrying a large variety of sizes in stock will, to a considerable extent, be eliminated since the Year tip, which is the critical part of the ear piece, can easily be adjusted to fit varying sizes of auditory canals.

Once the ear tip has been adjusted by the fitter to the customer the inflated torus provides a yielding cushion seal that will adapt itself to all changes in shape of the ear canal and thus provide a good seal despite such changes. It is apparent that the inflation or deflation of the torus is not necessarily limited to the fitter from whom the ear piece is purchased but may be controlled by the wearer after he has become familiar with the adjustment best suited to his needs. The necessity therefore of periodically returning The torus 6 in the embodiment shown lies I 4 to a dealer in audiphone equipment to obtain a new car piece every time there is a slight change in size of the auditory canal is eliminated.

It is apparent that hollow inflatable tori or annulate elements of various types and forms may be used, for example the base member 1 of the embodiment shown, need not be of rubber nor even of a flexible material so long as a tight seal is maintained between the base I and the outer surface of the ear tip to prevent any air leakage therebetween. Furthermore, the top arcuate section 8 need not necessarily be formed of rubber but may be made 01"- any elastic material provided the material is sufficiently impervious to prevent any leakage of the inflating fluid therethrough; it would also not be necessary to form the whole of arcuate section 8 of a material having self-sealing properties but only a small portion thereof may be formed, if desired, of selfsealing material to receive the needle 9. The arcuate portion 8 may even be attached at its edges to the ear tip 4 by means of a suitable rubber or other cement, thus eliminating th base 1' yet permitting inflation in the manner hereinbefore described.

It is further apparent that the inflatable torus may take a number of diiierent forms in cross section, such as circular, elliptical, rectangular, etc. and may extend over a lesser or agreater portion of the ear tip as desired. Other valve means than the use of a self-sealing material also be provided for the insertion of the inflating fluid into the hollow torus, such, for example, as providing a fluid conduit passing through the ear piece and having one end'of the conduit terminating in communication with the interior of the torus t and the other end of the fluid conduit emerging at some point on the surface of the ear piece as separate from the ear tip and being provided with a conventional valve.

It is apparent from the foregoing that there may be numerous modifications and embodiments of the invention beside that which has been described and illustrated. The invention is therefore not to be limited to the particular embodiment shown as one method of carrying out the invention but should be only limited by that which is claimed.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

i. ear piece having an ear tip adapted to enter the auditory canal of the ear, and inflatable hollow flexible sealing means fixed surroundingly on said ear tip to prevent leakage of air between ear tip and said auditory canal.

2. In combination receiver, an ear piece secured to said receiver, said ear piece being provided with an ear tip having an air passage therethrough communicating with said receiver, said ear tip being adapted to enter the auditory canal of the ear and bearing hollow resilient sealing means thereon, said resilient sealing means being inflatably adjustable in diameter so as to closely fit auditory canals of varying internal diameters.

3. An ear piece for an audiphone receiver comprising a portion adapted to fit in the concha of an ear, an ear tip adapted to enter the auditory canal of the ear, and an inflatable hollow torus secured to the outer portion of said ear tip. the outer diameter of said hollow torus being adjustable by inflation so as to closely contact the inner walls of the auditory canal regardless of changes in diameter or contour of said auditory canal.

4. An ear piece having an ear tip adapted to enter the auditory canal of the ear, said ear tip having a hollow, flexible torus secured to its outer surface to prevent leakage of air between said ear tip and the inner surface of said auditory canal.

5. An ear piece for audiphone receivers having an ear tip adapted to enter the auditory canal of the ear, said ear tip having an inflatable torus around the outer periphery thereof adapted to provide a flexible seal between the outer surface of said ear tip and the inner surface of the auditory canal.

6. An ear piece for audiphone receivers having an ear tip adapted to enter the auditory canal of the ear, a hollow inflatable torus secured to the outer periphery of said ear tip to provide a flexible seal between the outer surface of said ear tip and the inner surface of the auditory .canal. said torus being of substantially greater ffwidth than depth.

.7. An ear piece as in claim 5 in which the inifl'atable torus comprises a flat annulate base member, and a top annulate member having its edges secured to the edges of said annulate base 5 member to provide a space therebetween adapted to receive an inflating fluid.

1 3. An ear piece for audiphone receivers having a flat annulate base member and a top annulate member. former of an elastic self-sealing material having its edges secured to the edges of said annulate base member to provide a space therebetween adapted to receive an inflating fluid.

9. An ear piece for audiphone receivers comprising a portion molded to fit the concha of the ear, an ear tip adapted to enter the auditory canal of the ear, an air passage extending through said. ear tip and said ear piece adapted to communicate with said receiver, a groove extending around the periphery of said ear tip, and an inflatable hollow flexible torus secured in said groove.

10. An ear piece for audiphone receivers comprising a portion adapted to fit the concha of the ear, an ear tip adapted to enter the auditory canal of the ear, and a flexible annulate member encircling said tip, the edges of said flexible annulate member being secured to the surface of said tip in such manner that the flexible annulate member defines, with the surface of the tip, a fluid-tight chamber.

REGINALD B. BLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,246,737 Knudsen June 24, 1941 2,430,229 Kelsey Nov. 4, 1947

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