Assistive listening device and human-computer interface using short-time target cancellation for improved speech intelligibility

A machine hearing device for generating speech signals to be used in identifying semantic content, and thereby allowing the performance of automated actions by related systems in response to the identified semantic content, the hearing device comprising:

• a set of microphones generating respective audio input signals arranged in an array having a plurality of microphone pairs arranged about a nominal listening axis with predetermined intra-pair microphone spacings;
• and
• audio circuitry configured to perform arrayed-microphone short-time target cancellation processing including (1) applying a short-time frequency transform to each of the respective audio input signals, thereby converting the respective time-domain signals into respective frequency-domain signals for every short-time analysis frame (2) calculating ratio masks from the frequency-domain signals of respective microphone pairs, wherein the calculation of a ratio mask includes a frequency domain subtraction of signal values of a microphone pair, (3) calculating a global ratio mask, which is an effective time-varying filter with a vector of frequency channel weights for every short-time analysis frame, from the plurality of ratio masks, and (4) applying the global ratio mask, and inverse short-time frequency transforms, to selected ones of the frequency-domain signals, thereby suppressing both stationary and non-stationary interfering sound sources and allowing for identification of the target speech signal.