Patent ID: 9640197
Date: 2017-05-02
CPC Classifications: G10L

Claim:
1. A method for extracting target speeches from a plurality of speeches originating from different directions of arrival, the method comprising: obtaining speech signals from each of a multiple of speech input devices disposed apart in predetermined distances from one another; calculating, based on the speech signals, a direction of arrival of target speeches and directions of arrival of other speeches other than the target speeches for each of at least one pair of speech input devices; calculating, for each of the at least one pair of speech input devices, an aliasing metric, based on the direction of arrival of the target speeches and the directions of arrival of the other speeches, wherein the aliasing metric indicates which frequency band of speeches is susceptible to spatial aliasing; enhancing, using an adaptive beamformer, speech signals arrived from the direction of arrival of the target speech signals, based on the speech signals and the direction of arrival of the target speeches, to generate the enhanced speech signals; reading a probability model, which is the product of a first normal distribution and a second normal distribution, wherein the first normal distribution is a model which has learned features of clean speeches and the second normal distribution is a model which has a mean in the probability distribution of the enhanced speech signals and is made so as to have a variance smaller than that of the first normal distribution in a case where the aliasing metric is close to zero; and inputting the enhanced speech signals and the aliasing metric to the probability model to output target speeches.