Adaptive efficient single/dual tone decoder apparatus and method
Apparatus and method for dual tone multifrequency signal detecti
Apparatus and method for identifying speech and call-progression
Apparatus and methods for electrical signal discrimination
Digital call progress tone detection method with programmable di
DTMF signal detection/removal using adaptive filters
Programmable ring generator
Selectively activated dual tone multi-frequency detector
Sensor circuit for voice/fax switch with cascaded amplifier circ
Telephone line monitoring system
Telephone or communication terminal with improved calling...
Voice detection
Voice detection
Voice/noise discriminator