Patent ID: 7464031
Filing Date: 2008-12-09
Classification: G10L

Abstract:
1. A speech recognition system, comprising: a features extractor that extracts a multitude of speech features directly from input speech; a log-linear function that receives the multitude of speech features obtained from the input speech and determines a posterior probability of each of a plurality of hypothesized linguistic units given the extracted multitude of speech features by applying the formula: where: H i is an index pointing to the ith word (or unit) k is a number of words (units) in the hypothesis T is a length of the speech signal w o with conditional probabilities represented by a maximum entropy log-linear model: where: λ f Z is a normalization factor that ensures that Equation 2 is a true probability (will sum up to 1); and a search device that analyzes the posterior probabilities determined by the log-linear function to determine a recognized output of unknown utterances.