LOUD SPEAKING DEVICE AND ECHO CANCELLER

摘要

PROBLEM TO BE SOLVED: To constitute the whole of the device with a low cost by cancelling the echo by an adaptive filter and a non-adaptive filter in the case of the occurrence of the variance of the echo path characteristic. ;SOLUTION: A connection control means 2 connects a busy channel selected by a reception detection means 1 to a first signal path 3. When an interrupt occurs, the interrupt channel is connected to a second signal path 4. An adaptive filter(ADF) 5 estimates the echo passing round from the reception channel to the transmission channel while learning to generate a pseudo echo. When there are two busy reception channels, a non-adaptive filter(NADF) 6 loads a filter coefficient from the outside and estimates the passing-round echo to generate a pseudo echo. A subtractor 8 subtracts the pseuco echo signal from a transmission signal. A reception filter 9 performs operation to output a sound signal to right and left speakers 10 and 11, and an acoustic image is orientated in accordance with the position of a speaker on the picture.;COPYRIGHT: (C)1997,JPO