32. An analysis device comprising: a plurality of sensors for receiving a signal segment; a codebook configured to store parameters corresponding to a plurality of hypothesized power spectral density functions; a discriminant function calculation component configured to evaluate a likelihood of the hypothesized power spectral density function corresponding to the signal segment based on application of a discriminant 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; and a prior probability table configured to store prior conditional probabilities relating to the hypothesized power spectral density functions, wherein the discriminant function calculation component evaluates the likelihood of the hypothesized power spectral density functions corresponding to the signal segment based additionally on the prior conditional probabilities.
33. The device of claim 32 , wherein the codebook further includes: a first codebook configured to store parameters corresponding to a plurality of hypothesized speech power spectral density functions; and a second codebook configured to store parameters corresponding to a plurality of hypothesized noise power spectral density functions.