PROMPT INTERRUPT SYSTEM WITH VOICE-OPERATED PROMPT INTERRUPTFUNCTION, AND METHOD FOR CANCELING ECHO IN ADJUSTABLE WAY

PROBLEM TO BE SOLVED: To realize a system and a method canceling effectively echo in the voice recognition method in a telephone communication system including a prompt interrupt function operated in voice. SOLUTION: An incoming signal from a communication network during transmission of a transmission signal representing an output prompt message is stored in an interlace buffer 21 according to a buffer controller 22. A delay finder 27 discriminates a channel delay in the communication network based on the incoming signal and the transmission signal to store part of the incoming signal to a delay buffer 23 according to a channel delay and the length of an adaptive filter included in an echo canceller 24 to eliminate an echo of the incoming signal stored by the echo canceller 24 and to obtain a reinforced incoming signal for further signal processing.