Patents by Inventor Sue A. Evans

Sue A. Evans has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4307385
    Abstract: 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.
    Type: Grant
    Filed: November 22, 1978
    Date of Patent: December 22, 1981
    Assignee: Sue Ann Evans
    Inventors: Sue A. Evans, Clarence L. Rogers