ADAPTIVE REVERBATION CANCELLING APPARATUS

摘要

PURPOSE: An adaptive echo removing device of hierarchical structure is provided to be capable of removing echo by hierarchical filtering using a distortion estimator previously estimating and calculating the echo and the estimation value of the estimator. CONSTITUTION: A distortion estimator(300) estimates x1(n) signals distorted by the influence of a speaker when predetermined output signals x(n) is output through the speaker. An adaptive echo estimator(310) estimates the input signal which the output signal of the speaker is input to a mike in every sample to obtain its echo coefficient, and calculates an echo estimated value(y1) convoluted to the distortion estimation signal(x1(n)) according to the speaker passing estimated in the distortion estimator(300). An adaptive residual echo estimator(320) receives an error signal and the input signal of the mike to calculate a residual echo estimation coefficient(H) with respect to residual echo. An adaptive residual echo damper(330) convolutes the error signal and the residual echo estimation coefficient(H) to output a transmission signal s(n) which the residual echo is removed from input signal d(n) from the mike.