US4405831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for selective noise suppression for hearing aids
Assignee: Boston Scientific Neuromodulation Corp
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Filing: 1980-12-22
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Granted: 1983-09-20
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Expires: 2000-12-22
Abstract
Abstract Noise suppression apparatus is interposed between the transducer and the amplifier of a hearing aid, allowing the user to adjust the operation of an automatic level control circuit to provide suppression of background sounds with negligible effect on audibility of close-in sounds.
Inventors
- 👤 Robin P. Michelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:03
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3005; H03G3/301; H03G3/3015; H04; H04R; H04R25/00; H04R25/50; H04R25/502; H04R25/35; H04R25/356
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
192 words
An improved sound amplifying apparatus of the type which includes transducer means for converting sound signals into electrical signals, amplifying means, and means for audibly reproducing electrical signals, wherein the improvement is a selective signal level suppression circuit, the suppression circuit comprising: manually adjustable attenuating means responsive to electrical signals from the transducer means for selectively attenuating the transducer electrical signals; and automatic signal level control means, responsive to the attenuated transducer signals and to amplified signals from the amplifying means, for supplying the attenuated transducer signals to the amplifying means for amplification; the automatic signal level control means having means for limiting the level of the attenuated transducer signal which are supplied to the amplifying means to maintain the level of the amplified attenuated transducer signals from the amplifying means at no greater than a predetermined threshold value, whereby adjustment of the attenuation provided by the manually adjustable attenuating means modifies the response of the signal level suppression circuit to the transducer electrical signals by altering the magnitude required in the transducer electrical signals before level limiting of the attenuated transducer signal will occur in the automatic signal level control means.
Claim 2
Dependent Claim
192 words
An improved sound amplifying apparatus of the type which includes transducer means for converting sound signals into electrical signals, amplifying means, and means for audibly reproducing electrical signals, wherein the improvement is a selective signal level suppression circuit, the suppression circuit comprising: manually adjustable attenuating means responsive to electrical signals from the transducer means for selectively attenuating the transducer electrical signals; and automatic signal level control means, responsive to the attenuated transducer signals and to amplified signals from the amplifying means, for supplying the attenuated transducer signals to the amplifying means for amplification; the automatic signal level control means having means for limiting the level of the attenuated transducer signal which are supplied to the amplifying means to maintain the level of the amplified attenuated transducer signals from the amplifying means at no greater than a predetermined threshold value, whereby adjustment of the attenuation provided by the manually adjustable attenuating means modifies the response of the signal level suppression circuit to the transducer electrical signals by altering the magnitude required in the transducer electrical signals before level limiting of the attenuated transducer signal will occur in the automatic signal level control means.
Claim 3
Dependent Claim
76 words
The combination of claim 1, wherein the apparatus generates internal electrical signal noise, wherein the manually adjustable attenuating means can be adjusted to a predetermined maximum attenuating value, and wherein at said value there is sufficient attenuation of the internal electrical noise supplied to the amplifying means by the manually adjustable attenuating means to prevent audible reproduction of the amplified electrical noise, while simultaneously allowing the electrical signals from the transducer means to be audibly reproduced.
Claim 4
Dependent Claim
170 words
The combination of claim 2, further comprising a first resistance and wherein the electrical signals are supplied to the amplifying means through the first resistance, and wherein the manually adjustable attenuating means comprise a variable resistance connected in series with a second, fixed resistance, and wherein the first resistance and the variable and second resistances form a voltage divider, so that an increase in value of the variable resistance causes a decrease in the proportion of electrical signal dissipated by the first resistance and a corresponding increase in proportion of electrical signal supplied to the amplifying means, while a decrease in value of the variable resistance causes an increase in the proportion of electrical signal dissipated by the first resistance and a corresponding decrease in the proportion of electrical signal supplied to the amplifying means, the value of the second resistance being selected to fix a maximum proportion of electrical signal which will be dissipated in the first resistance when the variable resistance is adjusted to a zero resistance value.
Claim 5
Dependent Claim
91 words
The combination of claims 2 or 3, wherein the automatic signal level control means comprise: level detecting means, responsive to the amplified electrical signal level, for producing a control signal when the amplified electrical signal level exceeds a predetermined value, wherein the control signal has a magnitude representative of the amount by which the predetermined value has been exceeded; automatic attenuating means supplied with the control signal, the automatic attenuating means connected in parallel with the manually adjustable attenuating means for attenuating the electrical signals in response to the control signal.
Claim 6
Dependent Claim
37 words
The combination of claim 4, wherein the level-limited signals have high level transients, further comprising spike suppression means, interposed between the amplifier means and the reproducing means, for suppressing the high level tranients in the level-limited signals.
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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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |