Patent ID: 7324940

Claim:
A method of determining a confidence score for decoding of a speech input by a speech recognition engine, in which the engine decodes the speech input using a grammar comprising a plurality of phonemes, the method comprising: receiving an ordered string of phonemes, wherein the phonemes of the string are identified by a speech recognition engine as being part of a speech input, wherein each phoneme is associated with a time frame, and wherein the speech input spans a time period comprising a plurality of time frames; receiving a phoneme acoustic score map, wherein the map comprises an acoustic score for each phoneme of a grammar at each of the plurality of time frames; obtaining a first sum comprising the addition of the highest acoustic scores in each of the time frames; obtaining a second sum comprising the addition of the lowest scores in each of the time frames; determining a confidence score for a best path for the ordered string of phonemes, wherein the confidence score is determined as a weighted average based at least in part on a functional relationship between the best path score, the second sum, and the first sum.