Method of determining uncertainty associated with acoustic distortion-based noise reduction

1. A method comprising:

reducing noise in a representation of a portion of a noisy signal to produce a representation of a portion of a noise-reduced signal using an acoustic-environment model;

identifying an uncertainty associated with reducing the noise by computing a difference between an expectation for the square of the portion of the noise-reduced signal and the square of the expectation for the portion of the noise-reduced signal; and

using the uncertainty and the portion of the noise-reduced signal to decode a pattern state.

2. The method of claim 1 using the uncertainty and the portion of the noise-reduced signal to decode a pattern state comprises:

using the uncertainty to adjust a probability distribution to form a modified probability distribution; and

using the representation of a portion of the noise-reduced signal and the modified probability distribution to decode the pattern state.

3. A computer-readable medium having computer-executable instructions for performing steps comprising:

converting a frame of a noisy signal into a feature vector comprising at least two components;

reducing noise in a component of the feature vector for the noisy signal to produce a component of a feature vector for a cleaned signal by utilizing an acoustic distortion model;

identifying an uncertainty associated with reducing the noise from the component by computing a difference between an expectation for a square of a feature vector for a cleaned signal and a square of the expectation for a feature vector for a cleaned signal; and

using the uncertainty to decode a phonetic state.

4. The computer-readable medium of claim 3 wherein the computer-executable instructions perform further steps comprising:

determining a probability component of a probability for a phonetic state based in part on the component for the cleaned signal and the uncertainty associated with reducing the noise from the component; and

using the probability component to determine the probability of the phonetic state regardless of the value of the uncertainty.

5. The computer-readable medium of claim 4 wherein determining a probability component comprises defining a probability distribution based in part on the uncertainty.

6. The computer-readable medium of claim 5 wherein defining a probability distribution comprises adding the uncertainty to a variance of a probability distribution.