US 3366197 A
Description (OCR text may contain errors)
Jan. 30, 1968 G. ROSENSTAND ARRANGEMENT IN RECEIVERS FOR PLACING IN THE AUDITORY CANAL Filed July 22, 1965 Fl. i
INVENTOR GERD ROSENSTAND fizz/7 ATTORNEYS United States Patent Gfiice 3,356,197 Patented Jan. 30, 1968 3,366,197 ARRANGEMENT IN RECEIVERS FOR PLACING IN THE AUDITORY CANAL Gel-d Rosenstand, Copenhagen, Denmark, assignor to Danavox International A/S, Copenhagen, Denmark Filed July 22, 1965, Ser. No. 474,048 Claims priority, application Denmark, Mar. 26, 1965, 1,575/65 7 Claims. (Cl. 18123) An improved hearing aid and more particularly an ear insert enclosed in thin distended membrane which effectively prevents foreign substances from penetrating into the receiver portion of the hearing aid.
In receivers in the form of ear inserts to be placed in the auditory canal there is the drawback that foreign substance, especially ear-wax, can penetrate into the receiver thereby causing considerable damage to the receiver. It is difiicult to undertake a cleansing operation without causing further damage to the receiver.
It is therefore an object of the invention to provide an arrangement in such receivers, whereby the above mentioned drawback is remedied. This is achieved, according to the invention, by providing the receiver with a housing having a sound opening, which extends in the longitudinal direction of the auditory canal. This sound opening is covered by a membrane made of a material which can vibrate in the manner of a diaphragm for the transmission of sound vibrations from the inside of the housing to the auditory canal. In this simple and effective way foreign matter is prevented from penetrating into the receiver. It has been found that by a suitable choice of membrane material, an excellent sound transmission may be obtained. Preferably a relatively thin membrane material is to be used. As a thin membrane would be relatively fragile, there will be a risk of rupture, but a new membrane can easily be provided, without giving rise to substantial additional costs.
The membrane may, according to the invention, be a part of a bag which is arranged so as to sheath the housing. In this manner an especially easy mounting of the membrane is obtained and it is easy for the user to exchange it. However, the membrane may be formed and arranged in another way, for example, as a small disc, which is adhered to the side of the housing over the opening, by means of, for example a self-adhering adhesive.
The bag may, according to the invention consist of a membrane material and have a flexible tightening edge at its opening. Such a bag can be made at extremely low cost and is easy to put on in the right way. The tightening edge can engage an oblique face of the housing, in such a manner, that it will pull the bag into its position, and thereby distend the bottom of the bag against the end face with the sound opening.
The bag may, according to the invention, have at least a bottom part of small wall thickness which acts as a diaphragm, and a considerably thicker side wall, which is arranged so as to encompass the receiver tightly and which has at least one annular swelling or bead, that serves to bear and provide a seal against the wall of the auditory canal. By means of such a bag the passage of sound along the receiver can be avoided. The bag is a cheap component, which easily can be exchanged. The bag may conveniently be moulded from latex rubber.
The interior volume, which is limited by the membrane and a diaphragm in the receiver, may, according to the invention, be relatively small, preferably being a narrow canal. In this manner a good frequency characteristic can be obtained for those frequencies that have a special importance in the optimum utilization a hearing aid.
The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding part of the specification. My invention, itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a longitudinal section of a hearing aid receiver illustrating one embodiment of the present invention; and
FIG. 2 is a longitudinal section, partially fragmented, of a second embodiment of this invention.
Referring to the embodiments illustrated in FIG. 1, a receiver 1 has a diaphragm that extends parallel and spaced from one of the longer sides of the receiver 1. The space between the one side and the diaphragm A is relatively narrow and provides a narrow sound canal B placed on one of the longer sides which is connected with a sound opening 2 in one of the end faces. The receiver 1 is placed in a housing 3, which consist of a yieldable material and is provided at one end, with a sound opening 4. At the other end, the housing 3 provided with a bottleneck 5. Over the housing 3 a bag 6, consisting of a thin membrane material and formed with a tightening edge 7, is distended, said edge pressing against the oblique sides of the housing 3, thereby holding the bag in position, so that its bottom part tightly bears against the inner end of the housing 3. The part of the bottom of the bag, that covers the sound opening 4, partly serves for preventing foreign substance from penetrating into the receiver 1, and partly served as a diaphragm for transmitting sound vibrations. The space, which is delimited by the bottom of the bag, end wall of housing 3, and the longer side and the diaphragm in the receiver, namely space E, 2, and 4, should not be too large. It is essential, that the housing 3 fit tightly around the receiver 1, since otherwise the above mentioned space B, 2, 4 would become too large.
Electrical conductors 8 are connected to the receiver 1 and extend out through a flexible tube 9, having at its lower end a thick edge 10'. On the outside of the bottleneck 5, a tightening ring 11 is placed, so as to prevent pulling-out of the flexible tube 9.
It has been found that latex rubber is especially suited as membrane material but the possibility that there may be plastic materials which may be also suitable, cannot be excluded. In a receiver, which substantially fills out the sectional area of the auditory duct, it has been found to be advantageous, for obtaining the sound transmission through the membrane to make the opening 4 as large as possible, but the possibility of having a somewhat smaller opening, when using an especially thin membrane material, cannot be excluded. In practice good results have been achieved with a circular opening, having an area of 813 mm. As the receiver has a rectangular sectional area, the opening could be somewhat larger, if it was oblong, but hereby, an improvement of the sound transmission seems not to be achieved, as it apparently is the largest sectional transverse dimension of the opening that is of importance for the sound transmission. On the other hand, an oblong opening may be better as to facilitate the introducing of the receiver into the housing 3.
It has been found advantageous to use very thin membrane material, for example 0.07 mm. thick, when using latex, and an opening having a cross sectional area of '8-13 mm. It must be assumed, that satisfactory results can be obtained with a membrane material having a thickness up to of 0.2 mm. Furthermore, it must be assumed to be advantageous to make the thickness of the membrane material still smaller, for example 0.02 mm.
At this reduced thickness care must be taken to insure that the membrane has the necessary mechanical strength. Over the area of the membrane itself the thickness, does not have to be great with regards to the mechanical strength, whereas it must be relatively large at the corners of the housing 3, and therefore, it might perhaps be of advantage to make the bag of varying thickness, so that it has an especially small thickness in the area of the membrane. As mentioned above, the volume of space B, 2, 4 within the diaphragm membrane should be small. In the embodiment shown in FIG. 1 this volume is determined by the magnitude of the opening 4 and the thickness of the housing 3. This thickness may, for example, be 0.6 mm. so that there will be, with a sectional area of the hole of 8-13 mm. a volume of 8 mmfi, thereby providing good results. The wall thickness of the housing can probably be made smaller around the opening 4, so that the volume becomes smaller. In a special form of the receiver 1, the volume can be made still smaller.
The embodiment illustrated in FIG. 2 comprises elements similar to those in the above described embodiment of FIG. 1, which were described by reference numerals 1, 2, 3, 4, 5, 8, 9, 10 and 11 and letters A and B. For purposes of clarity, and to avoid the crowding of the drawing, these reference numerals are not shown in FIG. 2. It will, however, be noted that the bag 6 having the tightening edge 7 shown in FIG. 1 is replaced by a bag 6a, that has a side wall 12 having a tightening edge 13 at the opening of the bag and an annular swelling or bead 14. The bottom of the bag has an area having a very small wall thickness and a magnitude corresponding to the opening 4. The bag 6a may be moulded from latex rubber. The swelling or bead 14 has such an outer diameter, that it can bear against and provide a seal with the wall of the auditory canal. The bag may be made of other material than latex rubber. The wall thickness of the area 15 may conveniently be 0 .2 mm. or less, whereas the side wall of the bag may have a thickness of for example 0.5 mm.
The shown and described embodiment is only to be considered as an example. A bag, as shown, may, for instance, be placed on a receiver, which is connected with a hearing aid, that is arranged to be placed at the outer ear or to be in a greater distance from the auditory canal, for example, behind the ear. On the outside of the bag it will often be of advantage to place a filling-out member for completely filling-out the auditory canal, thus avoiding sound transmission along with the receiver.
The receiver may form the one end of a hearing aid, which includes a microphone, an amplifier and a receiver, and is arranged to be introduced as a whole into the auditory duct in such a way, that the microphone is situated at the outer end and the receiver at the inner end.
While the invention has been explained by describing various embodiments thereof, it will be apparent that many modifications may be made without departing from the spirit and scope of the invention. It is, therefore, intended that all such equivalent variations are covered by the scope of the appended claims.
What is claimed is:
1. A hearing aid having an insert for placing in the auditory canal of an ear; said insert comprising a housing of a yielding material containing a receiver, the bottom wall of said housing having an opening for the insertion of said receiver, said receiver having a diaphragm parallel to and spaced from at least one of the side walls of said receiver and forming a sound canal therewith, said sound canal having an opening communicating with said housing bottom wall opening, and a disteneded thin membrane tightly sheathing said housing and covering said housing bottom wall opening, said membrane covering acting as a diaphragm to transmit vibrations received by said sound canal from said receiver diaphragm to the auditory canal and to prevent foreign substance from penetrating into said receiver.
2. A hearing aid according to claim 1 wherein said distended membrane is an elastic bag formed at its open end with an elastic tightening ring holding said bag tightly sheathed against said housing.
3. A hearing aid according to claim 2 wherein said bag has an annular bead spaced from said ring and projecting outwardly to engage and provide a seal against the wall of the auditory canal.
4. A hearing aid according to claim 1 wherein said membrane covering is of lesser thickness than the remainder of said distended membrane tightly sheathing said housing.
5. A hearing aid according to claim 1 wherein said membrane covering has a thickness of approximately 0 .07
6. A hearing aid according to claim 1 wherein said membrane covering has a thickness of between 0 .02 and 0.2. mm.
7. The combination of claim 1 and wherein said housing has an end distant from said opening thereof formed with an additional opening through which flexible electrical conductors pass to the exterior of said housing.
References Cited UNITED STATES PATENTS 2,641,328 6/1953 Beaudry 18l23 2,876,767 3/1959 Wasserman 128-l51 2,959,645 11/1960 Ladd l79107 3,061,689 10/1962 McCarrell et al. 179-l07 3,130,810 4/1964 Werner 181-24 3,197,576 7/1965 Martin 179-407 STEPHEN J. TOMSKY, Primary Examiner.