Patent US3868857A successfully refreshed from Google Patents.
US3868857A
Expired / Lapsed
US
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Audio dosimeter
Assignee: Teledyne Inc
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Filing: 1972-11-16
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Granted: 1975-03-04
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Expires: 1992-11-16
Abstract
Abstract An audio dosimeter for individual use determining exposure to sound energy as a function of both frequency and pressure level, with integration over the time of exposure and incorporating storage means preserving a quantitative measure of the exposure.
Inventors
- 👤 Edward L Maddox
- 👤 Robert A Pease
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:06
CPC Classifications
G; G01; G01H; G01H3/00; G01H3/10; G01H3/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
260 words
An audio dosimeter for individual use comprising, in series circuit in the order recited, electronic microphonic sound sensor means, a filter-amplifier provided with a feedback circuit receiving the a-c voltage output of said sound sensor means, said filteramplifier comprising an operational amplifier connected in circuit with a plurality of a-c filter networks each having individual band pass characteristics preselected to collectively interact to shape said a-c voltage output during transmission by said filter-amplifier to conform to the pattern of a preselected weighting network incorporating in said a-c voltage output the otolaryngologically (and psychologically) harmful contribution of ambient sound frequency, linear detector means rectifying said a-c voltage output from said filter-amplifier, said linear detector means incorporating a pair of oppositely connected diodes as rectifying elements, and said filter amplifier feedback circuit incorporating a pair of oppositely connected diodes preselected to compensate the forward voltage drops of said pair of diodes in said linear detector means and an impedance preselected to provide the desired linearity of rectification for small signals connected between signal ground and the junction of said compensating diodes on the feedback delivery side of said compensating diodes, a non-linear network shaping the d-c output current from said linear detector to the function required to produce a substantially straight line of correct slope in a plot of decibels referred to a preselected current level versus sound energy input level in decibels, and an electrochemical integrating cell receiving the output current from said non-linear network measuring sound exposure in terms of sound pressure with weighted freqency and time of exposure conjointly.
Claim 2
Dependent Claim
260 words
An audio dosimeter for individual use comprising, in series circuit in the order recited, electronic microphonic sound sensor means, a filter-amplifier provided with a feedback circuit receiving the a-c voltage output of said sound sensor means, said filteramplifier comprising an operational amplifier connected in circuit with a plurality of a-c filter networks each having individual band pass characteristics preselected to collectively interact to shape said a-c voltage output during transmission by said filter-amplifier to conform to the pattern of a preselected weighting network incorporating in said a-c voltage output the otolaryngologically (and psychologically) harmful contribution of ambient sound frequency, linear detector means rectifying said a-c voltage output from said filter-amplifier, said linear detector means incorporating a pair of oppositely connected diodes as rectifying elements, and said filter amplifier feedback circuit incorporating a pair of oppositely connected diodes preselected to compensate the forward voltage drops of said pair of diodes in said linear detector means and an impedance preselected to provide the desired linearity of rectification for small signals connected between signal ground and the junction of said compensating diodes on the feedback delivery side of said compensating diodes, a non-linear network shaping the d-c output current from said linear detector to the function required to produce a substantially straight line of correct slope in a plot of decibels referred to a preselected current level versus sound energy input level in decibels, and an electrochemical integrating cell receiving the output current from said non-linear network measuring sound exposure in terms of sound pressure with weighted freqency and time of exposure conjointly.
Claim 3
Dependent Claim
20 words
An audio dosimeter for individual use according to claim 1 wherein said preselected weighting network is an ''''A'''' weighting network.
Claim 4
Dependent Claim
43 words
An audio dosimeter for individual use according to claim 1 provided with a latching circuit detecting the receipt by said electronic microphonic sound sensor means of sound energy in excess of a preselected high energy level and retaining a record of said receipt.
Claim 5
Dependent Claim
52 words
An audio dosimeter for individual use according to claim 1 provided with a latching circuit detecting the receipt by said electronic microphonic sound sensor means of sound energy in excess of a preselected high energy level provided with a light-emitting diode as indication means for readout of said record of said receipt.
Claim 6
Dependent Claim
66 words
An audio dosimeter for individual use according to claim 1 provided with low level detection means sensing the receipt by said electronic microphonic sound sensor means of sound energy below a preselected low energy level and means responsive to said low level detection means switching said electrochemical integrating cell out of measurement service during the receipt of said sound energy below said preselected low energy level.
Claim 7
Dependent Claim
102 words
An audio dosimeter for individual use according to claim 1 wherein said non-linear network shaping the d-c output current from said linear detector to the function required to produce a substantially straight line of correct slope in a plot of decibels referred to a preselected current level versus sound energy input level in decibels comprises a multiplicity of parallel-connected resistor paths automatically switched in at progressively higher signal voltage levels to provide preselected dynamic impedances collectively sufficient to obtain signal current doubling for preselected sound energy input levels in decibels conforming to a given permissible time exposure-sound pressure level pattern as standard.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |