Scheme for Utilizing Formant-Transition Cues in the Recognition of a Class of Prevocalic Consonants

Abstract

A computer program has been developed which attempts to measure the formant motions associated with consonant-vowel transitions. Input to the computer is sampled, quantized spectral data. The program first locates a point ≈50 msec after the start of the vowel, and computes the frequency locations of the first 3 formants at that time which is considered to be the end of the transition. All future measurements are based on the formant locations determined at this time. The program then selects another instant of time at the beginning of the transition. The choice of this instant depends upon the type of preceding consonant, and varies in such a way as to allow fricative- and plosive-burst energy to have died away and the formants to have begun to appear. Several measurements are made on the 2 spectral patterns so selected. The measurements compare the energy in frequency bands just above and just below both F2 and F3 as picked at the end of the transition. The measurements indicate the direction and magnitude of the formant motions. Data collected to date for fricatives and plosives show consistent trends and useful separation in most cases.