Patent attributes
A speech recognition method includes receiving signals derived from indices of a codebook corresponding to recognition feature vectors extracted from speech to be recognized. The signals include an indication of the number of bits per codebook index. The method also includes obtaining the string of indices from the received signals, obtaining the corresponding recognition feature vectors from the string of indices, and applying the recognition feature vectors to a word-level recognition process. To conserve network capacity, the size of the codebook and the corresponding number of bits per codebook index, are adapted on a dialogue-by-dialogue basis. The adaptation accomplishes a tradeoff between expected recognition rate and expected bitrate by optimizing a metric which is a function of both.