EUROSPEECH '95 Fourth European Conference on Speech Communication and Technology Madrid, Spain September 18-21, 1995

Rejection Capabilities for HMM-Based Speech Recognizers

Sari Accaino, Bart D'hoore, Johan Vantieghem, Dirk Van Compernolle

Lernout & Hauspie Speech Products N. V., Ieper, Belgium

We present a rejection method of out-of-vocabulary words assessed on two representations of extraneous speech inputs. First, we consider a garbage template to match the non keywords, named the ergodic 7-garbages model, which is directly built from the context independent (CI) phoneme models used to represent the keywords. In a second step, we do not attempt to explicitly model the extraneous inputs : this method refers to the ergodic best-fit model. The main motivation of using these two garbage models is that they do not require any specific training. We report results on rejection performance for speaker independent isolated words recognition task (perplexity 54) with standard discrete density HMM and hybrid HMM/MLP based recognizers.

Full Paper

Bibliographic reference.  Accaino, Sari / D'hoore, Bart / Vantieghem, Johan / Compernolle, Dirk Van (1995): "Rejection capabilities for HMM-based speech recognizers", In EUROSPEECH-1995, 2115-2118.