US3928733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hearing aid control circuit for suppressing background noise
Assignee: Viennatone GmbH
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Filing: 1974-11-20
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Granted: 1975-12-23
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Expires: 1994-11-20
Abstract
Abstract In a control circuit for a hearing aid, a threshold switch is connected to the low-frequency channel which transmits an input signal from a microphone to an earphone. This switch is arranged to block transmission of the signal below a set threshold level of the signal. The low-frequency signal in the channel controls the switch.
Inventors
- 👤 Fritz Hueber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:45
CPC Classifications
H; H04; H04R; H04R25/00; H04R25/50; H04R25/502
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
104 words
In a control circuit connected between a microphone and an emitter of a hearing aid, the microphone receiving an input signal and the circuit being arranged to transmit the input signal to the emitter, and the circuit including a low-frequency channel comprising a signal connected to the microphone and an output stage amplifying transistor connected to the emitter, the improvement of a threshold switching means connected to the lowfrequency channel and arranged to block transmission of the input signal from the microphone to the emitter below a predetermined threshold level of the signal, the low-frequency signal in the low-frequency channel controlling the switching means.
Claim 2
Dependent Claim
104 words
In a control circuit connected between a microphone and an emitter of a hearing aid, the microphone receiving an input signal and the circuit being arranged to transmit the input signal to the emitter, and the circuit including a low-frequency channel comprising a signal connected to the microphone and an output stage amplifying transistor connected to the emitter, the improvement of a threshold switching means connected to the lowfrequency channel and arranged to block transmission of the input signal from the microphone to the emitter below a predetermined threshold level of the signal, the low-frequency signal in the low-frequency channel controlling the switching means.
Claim 3
Dependent Claim
18 words
In the hearing aid control circuit of claim 1, means for adjusting the threshold level of the signal.
Claim 4
Dependent Claim
27 words
In the hearing aid control circuit of claim 1, the low-frequency channel comprising at least one transistor and the threshold switching means being connected to the transistor.
Claim 5
Dependent Claim
23 words
In the hearing aid control circuit of claim 3, the transistor being the amplifying transistor connected to the emitter of the hearing aid.
Claim 6
Dependent Claim
43 words
In the hearing aid control circuit of claim 1, the threshold switching means comprising a switching transistor having a collector-emitter path, and the low-frequency channel comprising at least one transistor having a base contact, the collector-emitter path being connected to the base contact.
Claim 7
Dependent Claim
19 words
In the hearing aid control circuit of claim 5, the transistor in the low-frequency channel being the amplifying transistor.
Claim 8
Dependent Claim
24 words
In the hearing aid control circuit of claim 5, the switching transistor and the low-frequency channel transistor connected thereto constituting a bistable flip-flop stage.
Claim 9
Dependent Claim
54 words
In the hearing aid control circuit of claim 5, the amplifier having an output, a further amplifying transistor having an input and an output, the output of the amplifier transmitting alternating circuit to the input of the further amplifying transistor, and the output of the further amplifying transistor being connected to the switching transistor.
Claim 10
Dependent Claim
41 words
In the hearing aid control circuit of claim 8, a decible adjusting means connected between the amplifier and the further amplifying transistor, the high point of the decible adjusting means transmitting alternating current to the input of the further amplifying transistor.
Claim 11
Dependent Claim
44 words
In the hearing aid control circuit of claim 8, a resistance connected between the further amplifying transistor and the switching transistor for transmitting a control voltage to the switching transistor, and means for adjusting the control voltage whereby the threshold value may be adjusted.
References Cited (Backward Citations)
US3101081A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |