04158749 is referenced by 7 patents and cites 3 patents.

An audio squelch circuit uses spectral analysis of the audio signal to derive two test signals, one of the two indicating speech presence "energy" and the other "voiced" speech presence. The two test signals are logic-AND combined to decide speech presence and open the squelch gate. Detection of speech in the audio signal, composed of a voiced segment which is both preceded and followed by a non-voiced (consonant) segment, is improved by correspondingly lengthening the "voiced" test signal pulse with both earlier (anticipatory) initiation by a time interval "D," and with a later (prolonged) completion by a time interval "d".

Title
Arrangement for discriminating speech signals from noise
Application Number
5/875679
Publication Number
4158749
Application Date
February 6, 1978
Publication Date
June 19, 1979
Inventor
Jean Potage
Paris
FR
Pierre Deman
Paris
FR
Agent
Cushman Darby & Cushman
Assignee
Thomson CSF
FR
IPC
G10L 1/00
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