Acoustic source separation systems

A method for acoustic source separation, the method comprising:

• inputting acoustic data from a plurality of acoustic sensors, said acoustic data comprising acoustic signals combined from a plurality of acoustic sources;
• converting said acoustic data to time-frequency domain data comprising a plurality of time-frequency data frames for a plurality of times and frequencies;
• and
• constructing a multichannel filter to operate on said time-frequency data frames to separate signals from said acoustic sources;
• wherein said constructing comprises:
• determining a set of de-mixing matrices (Wf), one for each of said plurality of frequencies, to apply to each said time-frequency data frame to determine a vector of separated outputs (yft), wherein said determining comprises modifying each of said de-mixing matrices by a respective gradient value (G;G′) for a said frequency dependent upon a gradient of a cost function measuring a separation of said sources by the respective said de-mixing matrix;
• and
• wherein said respective gradient values for each frequency are each calculated from a stochastic selection of said time-frequency data frames.

A system for acoustic source separation, the system comprising:

• one or more inputs to receive acoustic data from a plurality of acoustic sensors, said acoustic data comprising acoustic signals combined from a plurality of acoustic sources;
• and
• an audio signal processor coupled to said one or more inputs, the audio signal processor comprising:
• a time-to-frequency domain converter to convert said acoustic data to time-frequency domain data comprising a plurality of time-frequency data frames for a plurality of times and frequencies;
• and
• a multichannel filter module to operate on said time-frequency data frames to separate signals from said acoustic sources;
• and
• wherein said audio signal processor is further configured to:
• determine a set of de-mixing matrices (Wf), one for each of said plurality of frequencies, to apply to each said time-frequency data frame to determine a vector of separated outputs (yft), by modifying each of said de-mixing matrices by a respective gradient value (G;G′) for a said frequency dependent upon a gradient of a cost function measuring a separation of said sources by the respective said de-mixing matrix;
• and to
• calculate said respective gradient values for each frequency from a stochastic selection of said time-frequency data frames.

A method for acoustic source separation or adaptive beamforming, the method comprising:

• inputting acoustic data from a plurality of acoustic sensors, said acoustic data comprising acoustic signals combined from a plurality of acoustic sources;
• converting said acoustic data to time-frequency domain data comprising a plurality of time-frequency data frames for a plurality of times and frequencies;
• and
• constructing a multichannel filter to operate on said time-frequency data frames to perform said acoustic source separation or adaptive beamforming by determining a set of matrices to apply to each said time-frequency data frame, and assigning a weight to each of a set of said time-frequency data frames when constructing said multichannel filter.