Speaker-dependent speech recognition based on phone-like units models-application to voice dialling

This paper presents a speaker dependent speech recognition with application to voice dialling. This work has been developed under the constraints imposed by voice dialling applications, i.e., low memory requirements and limited training material. Two methods for producing speaker dependent word baseforms based on phone-like units (PLU) are presented and compared: (1) a classical vector quantizer is used to divide the space into regions associated with PLUs; (2) a speaker independent hybrid HMM/MLP recognizer is used to generate speaker dependent PLU based models. This work shows that very low error rates can be achieved even with very simple systems, namely a DTW-based recognizer. However, the best results are achieved when using the hybrid HMM/MLP system to generate the word baseforms. Finally, a real-time demonstration simulating voice dialling functions and including keyword spotting and rejection capabilities has been set up and can be tested online.