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Active hearing protectors

  • US 4,677,678 A
  • Filed: 07/10/1984
  • Issued: 06/30/1987
  • Est. Priority Date: 07/10/1984
  • Status: Expired due to Fees
First Claim
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1. A hearing protective device comprisinga headset having a headband;

  • audio transducer assemblies secured to opposite ends of said headband;

    each of said audio transducer assemblies including a microphone and a sound reproducer;

    circuit means including two respective stereo audio channels connecting said microphone and said sound reproducer of each of said respective audio transducer assemblies;

    attenuation circuit means having an input connected to receive simultaneously the outputs of said microphones;

    said attenuation circuit means includingmeans to generate two symmetrically similar attenuation current signals with amplitudes in accordance with the combined outputs of said microphones;

    said generating means includinghyper automatic gain control circuitry means to substantially progressively lower output currents of said stereo audio channels as the combined outputs of said microphones continue to rise after exceeding a predetermined level;

    and means to feed back the respective attenuation current signals to said stereo audio channels at locations therein which affect respective output currents of said stereo audio channels;

    said headset having movable switching means mounted thereon to switch said headset on and off.

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