Speech Recognition
Under its Improved Spoken-Language Understanding
project, SRI International has
continued to develop the DECIPHER speaker-independent,
continuous-speech recognition system based on hidden Markov models
(HMM). Optimum HMM state clustering, Gaussian mixture modeling, and
statistical language modeling are combined to give state-of-the art
performance. In addition, robustness to different acoustic
environments such as channels, noise, and nonnative speakers is
achieved through noise-robust feature extraction and acoustic
adaptation technology. Real-time applications, such as the
CommandTalk interface developed under this project for military
simulation systems, make use of the Nuance recognizer, developed by Nuance Communications, a spin-off
from SRI's Speech Technology and
Research (STAR) Laboratory. Close collaboration between the STAR
laboratory and Nuance Communications facilitates the quick integration
of novel research conducted by STAR laboratory researchers into the
Nuance recognizer.