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.