The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 1976
Filed:
Jun. 27, 1974
Uno Randmere, Victor, NY (US);
Morris A Suntop, Rochester, NY (US);
Stromberg-Carlson Corporation, Rochester, NY (US);
Abstract
A loudspeaking telephone system including voice switching is disclosed. The system is bistably voice controlled by inversely regulating the impedances of variolossers in the transmit and receive channels respectively. Further provision is made for switching additional impedance in parallel with each variolosser control to provide for a loud and a soft receiving mode. Hysteresis is added to the bistable control by the summation of receive and transmit signals across a plurality of unequal impedances that form part of a novel input control means. Circuitry forming the input control means also includes noise guard means useful in discriminating between ambient noise signals and syllabic speech signals. The noise guard circuit discriminates between noise signals and speech signals by producing an output whose amplitude is substantially related to ambient noise conditions while the noise guard circuit generally is not responsive to rapidly fluctuating voice signals. The output of the noise guard circuit is then summed with the transmit and receive signals across unequal impedances to prevent seizure of the bistable control by ambient noise.