DEVICE FOR DETECTING SPEECH SIGNALS AND TRANSMIT-RECEIVE SWITCHING SYSTEM COMPRISING SUCH A DEVICE

摘要

A detection apparatus for receiving an input signal containing noise and for detecting the presence of voice signals therein comprises means for attenuating the input signal and a comparator of the amplitude of the attenuated input signal relative to a variable threshold voltage. This threshold voltage is generated by control means which make the threshold voltage dependent on the peak amplitude value of the input signal. A control signal corresponding to the detection of voice signals is supplied by decision means which carry out a time analysis of the output signal of the comparator.