1. A system for processing audio data comprising: a linear demixing system operating on a processor and configured to receive a plurality of sub-band audio channels and to generate an audio output and a noise output; a spatial likelihood system operating on the processor and coupled to the linear demixing system, the spatial likelihood system configured to receive the audio output and the noise output and to generate a spatial likelihood function; a sequential Gaussian mixture model system operating on the processor and coupled to the spatial likelihood system, the sequential Gaussian mixture model system configured to generate a plurality of model parameters; a Bayesian probability estimator system operating on the processor and configured to receive the plurality of model parameters and a speech/noise presence probability and to generate a noise power spectral density and spectral gains; and a spectral filtering system operating on the processor and configured to receive the spectral gains and to apply the spectral gains to noisy input mixtures.