Patent ID: 11894010
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G

Claim 15:
16. A signal processing method comprising:
an estimation step of estimating a convolutional beamformer, wherein the convolutional beamformer is used for calculating, at each time point, a weighted sum of a current signal and a past signal of a sequence of past signals with a predetermined delay and a time duration of the sequence of past signals of zero length or more, and the estimating the convolutional beamformer further comprises:
receiving frequency-divided observation signals obtained from acoustic signals emitted from a target sound source;
calculating, at each time point of the sequence of time points, weights of the weighted sum as the convolutional beamformer, wherein the weighted sum causes the estimation signals of the target signals to increase a probability of speech-likeliness of the estimation signals based on a predetermined probability model; and

a suppression step of suppressing noise and reverberation associated with the frequency-divided observation signals to generate the estimation signals of the target signals by using the convolutional beamformer upon the frequency-divided observation signals, wherein
the probability expressing the speech-likeness is according to a signal distribution of speech in the estimation signals of the target signals, and an average of the estimation signals is 0 and a variance of the estimation signals varies over time.