30. A device for determining spectral parameters corresponding to a segment of signal, the device comprising: a plurality of sensors for receiving the segment of the signal; means for generating a hypothesized noise power spectral density function; means for generating a hypothesized speech power spectral density function; means for combining the hypothesized power spectral density functions to obtain a spectral hypothesis; and means for evaluating a likelihood that the spectral hypothesis corresponds to the segment of the signal based on application of the exact likelihood function evaluated using a preconditioned conjugate gradient (PCG) process configured for block Toeplitz type matrices with a block size corresponding to the number of sensors.
30. A device for determining spectral parameters corresponding to a segment of signal, the device comprising: a plurality of sensors for receiving the segment of the signal; means for generating a hypothesized noise power spectral density function; means for generating a hypothesized speech power spectral density function; means for combining the hypothesized power spectral density functions to obtain a spectral hypothesis; and means for evaluating a likelihood that the spectral hypothesis corresponds to the segment of the signal based on application of the exact likelihood function evaluated using a preconditioned conjugate gradient (PCG) process configured for block Toeplitz type matrices with a block size corresponding to the number of sensors. 31. The device of claim 30 , further comprising: means for storing prior conditional probabilities conditioned upon at least one of a particular talker, particular group of talkers, or a particular noise environment, wherein the means for evaluating evaluates the likelihood of the hypothesized power spectral density functions corresponding to the signal segment based additionally on the prior conditional probabilities.