METHODS AND APPARATUS FOR DETECTING VOICE INFORMATION IN TELEPHONE-TYPE SIGNALS

Voice signal information in a telephone-type signal is detected by subjecting the signal to several tests such as a minimum energy test, an amplitude ratio test, and a sequencing test which ensures that the other tests have been satisfied for a sufficient length of time and/or sufficiently frequently over a predetermined time interval. A voice processing system such as a voice mail system may use the detection of voice as above to initiate the transmission of an announcement or message during an automatically placed telephone call.