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Personal acoustic alarm system

  • US 4,473,821 A
  • Filed: 02/12/1982
  • Issued: 09/25/1984
  • Est. Priority Date: 02/12/1982
  • Status: Expired due to Fees
First Claim
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1. A personal acoustic alarm unit for providing an audible alarm signal in the audio range comprising a transmitter means including signal generating means for simultaneously generating a plurality of individual sonic signals in the audio frequency range, each such sonic signal having an audio frequency which differs from that of the remaining sonic signals, code generator means connected to receive at least one of said individual sonic signals and operating to apply a unique code thereto, and means for transmitting said sonic signals simultaneously as an audible alarm signal.

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