Abstract: The performance of speech recognition depends on the choice of speech parameters. A systematic and practical method of the parameters selection based on the variance orthogonal test design was proposed. Firstly,chose factors (speech parameters) and levels. And then according to the principle of mathematical statistics and orthogonality, picked out proper and representative points from a large number experimental points to construct orthogonal table. Finally, calculated and analysed the experimental results, and the optimal set of process parameter values was discovered. Moreover, the word error rate is reduced 5. 6% and response time is reduced 181. 37ms when compared with that of the traditional parameter selection method. The experiment results show that the application of orthogonal test design is effective in parameter optimisation. The conclusion provides guidance for the subsequent research.

Key words: Orthogonal test design, Speech recognition, Parameter optimization, Orthogonafity