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US 4,307,385 AGranted
Noise monitoring apparatus
AssigneeSue Ann Evans
InventorsSue A. Evans, Clarence L. Rogers
Life of this patent
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AssigneeSue Ann Evans
InventorsSue A. Evans, Clarence L. Rogers
Estimating the term…
An apparatus for monitoring the noise which impinges a human ear and for generating a signal representing the noise level accumulated over a period of time. Typically, the apparatus can be located in a hearing protector worn by a worker in a noisy environment. A microphone generates a signal having a magnitude representing the detected noise level of the ear which signal is processed by an absolute value circuit and a root mean square circuit to generate a signal having a magnitude proportional to the logarithm of the detected noise level. This logarithmic signal is converted by a voltage to frequency converter and a counter accumulates a count total proportional to the noise level over a period of time. The apparatus includes visual and aural alarms to indicate a maximum allowed noise level and dosage. The apparatus can also be inserted into a storage unit for reading the data, calibrating the noise monitor circuitry and recharging the batteries in the apparatus.
A hearing protector and noise monitor apparatus adapted to be worn in a noisy environment, comprising:
A hearing protector and noise monitor apparatus adapted to be worn in a noisy environment, comprising:
A system for monitoring noise including a noise monitor apparatus adapted to be worn in a noisy environment and a storage unit for generating a train of clock pulses and receiving a noise dosage signal from the noise monitor apparatus, the noise monitor apparatus comprising:
Dependencies are inferred from the claim text.