Patent ID: 7447630

Claim:
A method of determining an estimate for a noise-reduced value representing a portion of a noise-reduced speech signal, the method comprising: generating an alternative sensor signal using an alternative sensor other than an air conduction microphone; converting the alternative sensor signal into at least one alternative sensor vector in the cepstral domain; adding a weighted sum of a plurality of correction vectors to the alternative sensor vector to form the estimate for the noise-reduced value in the cepstral domain, wherein each correction vector corresponds to a mixture component and each weight applied to a correction vector is based on the probability of the correction vector's mixture component given the alternative sensor vector; generating an air conduction microphone signal; converting the air conduction microphone signal into an air conduction vector in the power spectrum domain; estimating a noise value; subtracting the noise value from the air conduction vector to form an air conduction estimate in the power spectrum domain; converting the estimate of the noise-reduced value from the cepstral domain to the power spectrum domain; and combining the air conduction estimate and the estimate for the noise-reduced value in the power spectrum domain to form the refined estimate for the noise-reduced value in the power spectrum domain.