Sixth European Conference on Speech Communication and Technology

Budapest, Hungary
September 5-9, 1999

Comparison of Continuous-Density and Semi-Continuous HMM in Isolated Words Recognition Systems

T. Vaich, A. Cohen

Speech R&D Center, DSP-Group Omer, Israel

Several types of Semi-Continuous HMM (SC-HMM) have been compared with the Continuous Density HMM (CD-HMM) in the context of Speaker Independent Isolated Words Recognition (SI-IWR). It is demonstrated that for the ten-digit vocabulary (TIDIGITS), the SC-HMM outperforms the CD-HMM when memory constraints are imposed on the system. SC-HMMs demonstrate recognition rate of about 95% with a total of 59 Gaussians, while under similar conditions the CD-HMM yield recognition rates of well below 80%. An algorithm for optimal selection of Gaussian functions for SC-HMM is presented.

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Bibliographic reference.  Vaich, T. / Cohen, A. (1999): "Comparison of continuous-density and semi-continuous HMM in isolated words recognition systems", In EUROSPEECH'99, 1515-1518.