Nabil N. Bitar
Armen Y. Balian
Elec. Comput. and Systems Eng. Dept., Boston Univ., Boston, MA 02215
An automatic method was developed to classify fricatives as strident/nonstrident. The method is based on relative energy measures in the frequency bands (2--4 kHz, 4--6 kHz, and 6--8 kHz). Preliminary results based on 1176 fricative sounds extracted from sentences in the TIMIT database showed that most of the fricatives /(ess with hacek) z s z/ were classified as strident and most of the fricatives /f v (theta) (edh)/ were classified as nonstrident. An analysis of the remaining fricatives showed that their acoustic realizations differed substantially from their canonical form. The typically strident fricatives did appear to be ``weak'' and the typically nonstrident fricatives did appear to be ``strong.'' Factors influencing the change in the manifestation of these fricatives are phonetic context and stress. A detailed analysis of the observed variability will be presented.