12. The voice recognition method according to claim 10 , comprising: storing training data including at least one noise; taking a noise included in the training data as observed data; and updating the stored suppression coefficient and the adaptation coefficient, on the basis of a suppression coefficient and an adaptation coefficient which maximize an expected value of a likelihood function which takes a suppression coefficient and an adaptation coefficient as parameters.
12. The voice recognition method according to claim 10 , comprising: storing training data including at least one noise; taking a noise included in the training data as observed data; and updating the stored suppression coefficient and the adaptation coefficient, on the basis of a suppression coefficient and an adaptation coefficient which maximize an expected value of a likelihood function which takes a suppression coefficient and an adaptation coefficient as parameters. 17. The voice recognition method according to claim 12 , comprising: storing the value of the suppression coefficient or adaptation coefficient before the update when updating a value of the stored suppression coefficient or adaptation coefficient; and updating the stored suppression coefficient and adaptation coefficient, when the differences between the suppression coefficient and the adaptation coefficient which are updated last, and the suppression coefficient and the adaptation coefficient which are updated before last are not both equal to or smaller than a predetermined threshold value.