A method and apparatus for discriminative
estimation of parameters in a maximum a posteriori (MAP)
speaker adaptation condition, and a voice recognition apparatus having the apparatus and a voice recognition method using the method are provided. The method for discriminative
estimation of parameters in a maximum a posteriori (MAP)
speaker adaptation condition, in which at least speaker-independent
model parameters and prior density parameters, which are standards in recognizing a speaker'
s voice, are obtained as the result of model training after fetching training sets on a plurality of speakers from a training
database, has the steps of (a) classifying
adaptation data among training sets for respective speakers; (b) obtaining
model parameters adapted from
adaptation data on each speaker by using the initial values of the parameters; (c) searching a plurality of candidate hypotheses on each uttered
sentence of training sets by using the adapted
model parameters, and calculating gradients of speaker-independent model parameters by measuring the degree of errors on each training
sentence; and (d) when training sets of all speakers are adapted, updating parameters, which were set at the initial stage, based on the calculated gradients.