Effect of preemphasis on vowel recognition performance

Preemphasis of the speech signal at higher frequencies is a preprocessing step employed in various speech processing applications. In the present paper, the effect of preemphasis on vowel recognition performance is studied. Preemphasis of the speech signal is achieved hy the r;-~.-'-"der ,4:rr . . . . . :,~ ~r . . . . . . . . . . . . . . . . . . . . . . . ,,. the speech signal. Ceostral coefficients derived through linear prediction analysis are used as recognition parameters. A minimum distance classifier is used for vowel recognition and the recognition performance is studied for four different distance measures: Euclidean distance measure, correlation distance measure, Mahalanobis distance measure and itakura distance measure. It is shown that preemphasis of the speech signal brings about a deterioration in the vowel recognition performance. Implications of this result for isolated word recognition are also