Patent US4750207A successfully refreshed from Google Patents.
US4750207A
Expired / Lapsed
US
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Hearing aid noise suppression system
Assignee: Sivantos Inc
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Filing: 1986-03-31
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Granted: 1988-06-07
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Expires: 2006-03-31
Abstract
Abstract A hearing aid responds to increased noise by changing its frequency response to reduce the effects of the noise. The hearing aid has a circuit which varies the frequency response of the unit as a function of low-frequency sounds, using a fast attack time and a much slower release time.
Inventors
- 👤 Anton M. Gebert
- 👤 Yuri Gokhin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:45
CPC Classifications
H; H04; H04R; H04R25/00; H04R25/50; H04R25/502; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/32; H03G5/00; H03G5/16; H03G5/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
A hearing aid circuit, comprising: a high-pass filter with adjustable frequency response; a bandpass filter; and an attack and release circuit connecting the bandpass filter to the high-pass filter in a manner that an increased output from the bandpass filter changes the frequency response of the high-pass filter after an attack time and a decreased output from the bandpass filter changes the frequency response of the high-pass filter after a release time which is much longer than said attack time.
Claim 2
Dependent Claim
80 words
A hearing aid circuit, comprising: a high-pass filter with adjustable frequency response; a bandpass filter; and an attack and release circuit connecting the bandpass filter to the high-pass filter in a manner that an increased output from the bandpass filter changes the frequency response of the high-pass filter after an attack time and a decreased output from the bandpass filter changes the frequency response of the high-pass filter after a release time which is much longer than said attack time.
Claim 3
Dependent Claim
32 words
The hearing aid circuit of claim 1, wherein said high-pass filter comprises a filter capacitor and said attack and release circuit comprises a transistor with its collector-emitter circuit shunting said filter capacitor.
Claim 4
Dependent Claim
59 words
The hearing aid circuit of claim 2, wherein said attack and release circuit further comprises a timing capacitor which is connected to the base of said transistor, a charging resistor through which said timing capacitor is clamped, and a discharging resistor thereof which said timing capacitor is discharged, said charging resistor having a lower resistance than said discharging resistor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |