Speaker dependent keyword spotting for accessing stored speech
KM Knill, SJ Young · Cambridge University Engineering Department Publications Database · 1994
This report investigates the use of a speaker-dependent HMM word-spotter to retrieve spoken messages. The baseline word-spotter consists of a parallel network of keyword and background filler models. A further pass, using the filler models only, can be used to re-score the putative keyword hits. Word-spotting performance using (i) whole-word and (ii) sub-word keyword models is investigated. For each keyword model type, effects on performance of re-scoring, Gaussian component number, and parameter set are evaluated on a set of spoken messages, taken from the Video Mail Retrieval database. Overall, sub-word models are shown to yield a higher hit rate, particularly before the first false alarm occurs.