Patent Document ID: 9445189
Application ID: 14565933
Patent Flag: 1

Claim One:
1. A noise suppressing apparatus, comprising: a frequency converting section that converts an input signal into a frequency spectrum; a noise level estimating section that calculates an estimated noise level of the input signal by using the frequency spectrum; a weight coefficient calculating section that calculates N weight coefficients at predetermined intervals, N being 2 or more; and a suppression coefficient calculating section that calculates a product of N statistical distribution models weighted by the N weight coefficients to obtain a joint distribution model of sound, derives an estimation expression for a sound spectrum of the input signal on the basis of posteriori probability using the calculated joint distribution model of sound as priori probability, and calculates a suppression coefficient for suppressing noise of the input signal on the basis of the derived estimation expression for the sound spectrum of the input signal and level of the input signal, wherein the joint distribution model of sound approximates a probability of occurrence of the sound spectrum of the input signal.