Patent ID: 8271277

Claim:
A dereverberation apparatus for eliminating late reverberation from an acoustic signal having the late reverberation, the dereverberation apparatus comprising: a memory that stores, for each of M channels, multiple discrete acoustic signals, the discrete acoustic signals of each channel m obtained by sampling, at multiple points in time, of the acoustic signal as observed by a respective one of M sensors, where m=1 to M, M≧1; a model application unit that calculates, by using the discrete acoustic signals, linear prediction coefficients α w,m (1), . . . , α w,m ([N/M]) of a multi-step linear prediction model x w ⁡ ( n ) = ∑ m = 1 M ⁢ ∑ p = 1 [ N / M ] ⁢ ⁢ α w , m ⁡ ( p ) · x m ⁡ ( n - p - D ) + e w ⁡ ( n ) where x w (n) is a discrete acoustic signal of a channel w at the discrete time n, w=1 to M, x m (n) is the discrete acoustic signal of the channel m at the discrete time n, m=1 to M, e w (n) is a prediction error of the channel w at the discrete time n, N is a positive integer, ● is a Floor function, α w,m (p) is a p-th linear prediction coefficient in a case the linear prediction target is x w (n), and D is a constant representing a step size; and a late reverberation predictor that outputs a linear prediction value as predicted late reverberation, r w (n), of the channel w at discrete times n, the linear prediction value is obtained by substituting the linear prediction coefficients α w,m (1), . . . , α w,m ([N/M]) and the discrete acoustic signals x m (n-P-D) into a linear prediction equation r w ⁡ ( n ) = ∑ m = 1 M ⁢ ∑ p = 1 [ N / M ] ⁢ ⁢ α w , m ⁡ ( p ) · x m ⁡ ( n - p - D ) of the multi-step linear prediction model.