US 3536861 A
Description (OCR text may contain errors)
Oct. 27, 1970 A. R. DUNLAVY HEARING AID CONSTRUCTION Filed Dec. 6, 1967 INVENTOR ALFRED R. DUNLAVY TTORNEY'.
FREQUENCY (C/S) FIG. 4.
ZOO 250 ABSTRACT F DISCLOSURE v A spectacle hearing aid constructionV whichincludes a United States Patent spectacle frame and a lpair of templev members connected thereto. A microphone is carried b y one member and respective amplifier-transducer circuits `which are connected to the microphone are carried by .the respective members. Connected to the output of one circuit is a r'st applicator responsive toV preselected Yfrequencies for applying such sounds to one ear. Connected to the output of the vother circuit is a second applicator responsive to the high end of such preselected frequencies for 4applying such sounds to the other ear to prevent low frequencies from being amplified.,
This invention relates generally toa spectacle hearing aid construction and, more particularly, pertains to a able for most applications, a problem arises when the aid is worn in an area having a relatively high environmental noise level. It has been found `that the environmental noise, which iscomposed predominantly of low frequency Asounds masks the high frequency. sounds thereby causing a deterioration of intelligible speech sounds, particularly if the tuser has trouble hearing high frequencyaudio signals. Hence, communication becomes extremely difficult for theperson using a hearing aid of thistype. .v
Accordingly, an object of the present invention is to .provide a spectacle hearing aid construction which is .ideally suited for use in noisy `environments.
Another object of this invention s to provide ahearing aid in which high frequency sounds are not masked by 'f low frequency noise.
A further object and Afeature ofthe vpresentv invention .resides in the novel details of construction which provide a device of the type described which is reliable lin operation.
Another object is to provide an aid for hearingwherein Y .acoustic feedback is reduced to a minimum. l
Still another object of the presentinvention is to provide a simpliiedand eicient hearing aid construction.
In furtherance of theabove. objects, the spectacle hearing aid construction of the present invention includes a spectacle frame having eyeglass supporting means and a pair of temple members connected thereto. A sound detecting means for converting sound vibrations into electrical signals is carried by one member. Also received in said frame is a sound reproducing means which is connected to said sound detecting means for amplifying the electrical signals and for converting the amplified signals back to sound vibrations. A irst applicator responsive to preselected frequencies in the audio range is con- Patented Oct. 27, 1970 ice nected to said sound reproducing means for applying such frequencies to one ear of a user. A second applicator responsive to the high end of said preselected frequencies is connected to said sound reproducing means for applying such high frequencies to the other ear of the user.
Thus, a feature of the present invention is to provide a spectacle hearing aid construction which applies a normal range of audio frequencies to one ear but only high frequency sound vibrations to the other ear so that the high frequency sounds only are reproduced when the user encounters a high level of environmental noise.
Other features and advantages of the present invention will become more apparent from a consideration of the following detailed description when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a top plan view of a spectacle hearing aid construction made in accordance with the present invention; f
FIG. 2 is a rear elevation thereof showing the eyeglass supporting portion of the spectacle frame;
FIG. 3 is a side elevational view of one of the temple members of the construction shown in FIG. 1; and
FIG. 4 is a graph of the sound pressure level showing the two distinct types of responsive curves obtainable with the one hearing aid of this invention.
A spectacle hearing aid construction made according to the present invention is designated generally by the reference numeral 10 in FIG. l and includes a spectacle frame 12 having an eyeglass supporting portion 14 and respective temple members 16 and 18'. More specifically, the eyeglass supporting portion 14 includes a pair of lens mounting members 20 connected together by a bridge 22 (see FIG. 2,). Respective nose engaging pads 24 extend rearwardly from the lens mounting members 20 to support the frame 12 on the nose bridge of the wearer. Connected to the ends of the lens mounting members 20 are hinges 26 which mount the respective temple members 16 and 18 on the eyeglass supporting portion 14 so that the temple members may be folded across the eyeglass supporting portion in the conventional manner.
The temple member 16 is hollow and includes a straight forward section 27 and a rear section Z8 which is curved inwardly and downwardly so that it will be received about the ear of the wearer'and engage the head of the wearer to securely mount'the frame 12 on the wearer. The member 16 is hollow and carries a microphone or sound detecting means 30 in the forward section 27 |which converts sound vibrations into corresponding electrical signals. It is to be understood that the microphone 30 communicates with the surrounding area by appropriate means (not shown) Asuch as an air channel or the like so that the sound vibrations may be applied to it. Moreover, the microphone is located forward of the ear.
Received in the rear section 28, and adapted to be located behind the ear, is` an amplifier-transducer circuit 32' which is connected to the microphone 30 by a lead 34 which extends through the member 16. The circuit 3-2 contains a battery and appropriate elements for amplifying the signals produced by the microphone 30 and for converting these amplied signals back to sound vibrations of increased amplitude. The circuit 32 also has means for selectively varying the Volume of the sound vibrations. It is to be noted that the microphone 30- and the circuit 32 are conventional in construction and, accordingly, will not be described in detail.
Connected to the output of the circuit 32 by a sound conducting tube 36 is a molded earpiece or applicator 38. As shown in FIGS. l and 3, the tube 36 passes through an appropriate aperture in the inside |Wall of the temple member 16. The earpiece 3,8 is likewise of conventional construction and it is adapted `to be received in one ear of a person to apply the sound vibrations produced by the circuit 32 to the ear. Moreover, use of the molded earpiece 38 substantially eliminates acoustic feedback since the earpiece completely stills the ear channel and prevents the escape of the audio sounds. The frequency response of the microphone 30, circuit 32 and the earpiece 38 may encompass a broad range of audio frequencies, such as ZOO-4000 c./s.
As shown in FIG. 4, the maximum frequency response of the earpiece 38, which is indicated by curve 40, occurs in the midrange frequencies of approximately 600-4000 c./s. Thus, both high and low frequencies are applied to the ear. However, if the environmental noise, which is substantially of low frequency, is relatively high, 'the high frequency end of the spectrum will be masked by the noise. Hence, the sound will becomeiunintelligible and the user of the device will not understand the conversation of other people. Accordingly, means are provided to apply exclusively high frequency sound vibrations to the other ear of the wearer to eliminate masking or loss of these sounds.
Thus, the temple member 18, similar to the temple member 16, includes a straight forward portion 42 and an inwardly and downwardly curved rear portion 44 which carries an amplifier-transducer circuit 46 Which is identical in construction to the circuit 32. That is, the circuit 46 likewise contains means for selectively varying the volume of the sound vibration. The circuit 46 is connected to the microphone 30 by a lead 48 which extends through the temple members 1f6 and 18 and the eyeglass supporting portion 14, as shown in FIGS. 1 and 2. Connected to the output of the circuit 46 is a plastic sound conducting openended tube 50 which passes through an appropriate aperture in the bottom wall of the member 18. The tube 50 is bent or otherwise shaped to be received directly in the other ear in a manner similar to that by which the earpiece 38 applies sound vibrations to the opposite ear. It is to be noted that the tube 50 is not carried by the temple member which carries the microphone 30 to reduce acoustic feedback. That is, the tube 50 and the microphone 30 are separated by the head of the wearer so that sound vibrations which may pass around the tube 50 and leak out of the ear channel will not be detected by the microphone 30 and thus cause acoustic feedback.
The frequency response to the tube 50 is shown by the dashed curve 52 in FIG. 4. It is to be noted that the frequency response of the tube 50 is substantially higher than that of the earpiece 38 with a peak occurring at a frequency of 2000 c./s. In other words, the tube 50 is responsive to the high end of the audio frequency spectrum to which the molded earpiece 38 is responsive. More particularly, it has been found that lthe frequency response of the tube 50 is 100G-4000 c,/s. It will now be appreciated that since only high frequencies are applied to the ear by the tube A50 and the frequency response of the aid drops off sharply at the low frequencies, as shown by the curve I52, low frequency environmental noise sounds will have no effect on the sound vibrations conducted by the tube 50. That is, the tube 50 will conduct unmasked high frequency sound vibrations to the ear-regardless of the fact that the microphone 30 may detect low frequency sounds such as environmental noise.
Since sound is applied to both ears, each ear will normally produce a sound image. Both images are transmitted to the brain where they combine to produce a single sound impression of what is heard. Hence, when a person enters a noisy environment the low frequency noise sounds will mask the high frequency intelligence sounds. Thus, the user turns down the volume control associated with the circuit 32 thereby attenuating the signals applied to the ear by the earpiece 38. Accordingly, the low frequency noise sounds will be attenuated. In view of this, the high frequency sounds applied to the ear by the tube 30 will no longer be masked by the low frequency noise sounds and the user will be able to detect thek high frequency signals.
Accordingly, a spectacle hearing aid construction yhas been described which conveys intelligible sounds to the `wearer in the presence of environmental noise.
While `,a preferred embodiment of the invention has been shown and described herein, it will be obvious that numerous omissions, changes and additions may be made in such embodiment without departing from the spirit and scope of the present invention.
What is claimed is:
1. A spectacle hearing aid construction comprising a frame including eye glass supporting means, and a pair of temple members connected thereto; i microphone in one of said temple members for conver lng sound vibration into electrical signals, sound reproducing means in said frame connected to said microphone fory amplifying said electrical signals and for converting said signals into amplified sound vibration, a first sound applicator means having a relatively broad frequency response over a band of preselected frequencies connected to said sound reproducing means for applying sounds of said preselected frequencies to the ear adjacent said one temple member, and the second sound applicator means having a frequency response limited to the high end of said band of preselected frequencies connected to said sound reproducing means for applying sounds of said high end of said band of preselected frequencies to the ear adjacent the other temple member.
2.v A hearing aid as defined in claim 1, in which said first applicator comprises a molded earpiece.
3. A hearing aid as in claim 1, in which said second applicator comprises an open-ended plastic tube.
4. A hearing aid as in claim 1, wherein said sound reproducing means comprises an amplifier-transducer circuit in each of said temple members, each of said circuits having a volume adjustment control, said first applicator being connected to one of said circuits and said second applicator being connected to the other of said circuits.
5. Ay hearing aid as in claim 1, in which said rst applicator comprises a molded earpiece, and a tube extending through said one temple member to connect said molded earpiece with said sound reproducing means; and said second applicator comprising an4 open-ended tube extending through the inner wall of said other temple member.
References Cited UNITED STATES PATENTS i 2,266,669 12/1941 Wengel 179--107 X 3,019,305 1/1962 McCarrell. 3,193,048 7/1965 Kohler. n 3,238,309 3/ 1966 Christoffersen.
3,394,226 7/1968 Andrews 179--107 X KATHLEEN H. CLAFFY, Primary Examiner T. L', KUNDERT, Assistant Examiner