4. The device of claim 1 , further comprising: a prior probability table configured to store prior conditional probabilities of first speech spectral parameters following second speech spectral parameters.
4. The device of claim 1 , further comprising: a prior probability table configured to store prior conditional probabilities of first speech spectral parameters following second speech spectral parameters. 5. The device of claim 4 , wherein the discriminant function calculation component evaluates the likelihood of the hypothesized speech power spectral density functions corresponding to the signal segment based additionally on the prior conditional probabilities.