ECHO CANCELING CIRCUIT, ACOUSTIC APPARATUS, NETWORK CAMERA, AND ECHO CANCELING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an echo canceling circuit, an acoustic apparatus, a network camera and an echo canceling method to rapidly reduce a noise generated by an echo component. SOLUTION: The network camera has an initial value memory 62 to store in advance an impulse response coefficient (h) to express a correlation between a sound input signal (e) and a sound output signal (s) obtained by a microphone 3, when the sound output signal (s) received by a communication I/F 61 is converted into an acoustic wave by a loudspeaker 2; an impulse response coefficient calculator 661 to calculate a new impulse response coefficient (h) regarding the impulse response coefficient (h) stored in the initial value memory 62 as the initial value, based on the sound output signal (s) and the sound input signal (e); an estimated echo signal generator 67 to estimate the estimated echo signal (e') from the sound output signal (s) and the impulse response coefficient (h); and an adder 68 to output a combined signal (r) obtained by deducting the estimated echo signal (e') from the sound input signal (e). COPYRIGHT: (C)2008,JPO&INPIT