An analysis of binaural spectro-temporal masking as nonlinear beamforming

Array-based time-frequency masking algorithms are an important type of nonlinear array processing. In this paper we develop a model that characterizes the directional sensitivity of these algorithms in a fashion similar to commonly-used the beam patterns used to characterize linear array processing. Two alternative formulations are described, and it is shown that one of these formulations predicts signal distortion and processing gain in time-frequency masking accurately, as well as speech recognition accuracy afforded by time-frequency masking in the presence of additive interfering sources.