Patent ID: 8363821
Filing Date: 2013-01-29
Classification: H04M

Abstract:
1. An echo cancellation apparatus comprising: an output unit configured to output a first acoustic signal; an input unit configured to input a second acoustic signal in response to the first acoustic signal; a filter unit configured to generate a third acoustic signal by convoluting the first acoustic signal with coefficients; a subtraction unit configured to generate a fourth acoustic signal by subtracting the third acoustic signal from the second acoustic signal; an estimation unit configured to decide whether a sound volume of the first acoustic signal is below a predetermined threshold, and to set a sound volume of the second acoustic signal as a non-echo sound level, when the sound volume of the first acoustic signal is below the predetermined threshold; a determination unit configured to determine a step size to correct the coefficients using the non-echo sound level; and a correction unit configured to correct the coefficients using the step size.