Study of the effects of vocal tract constriction on glottal vibration.

Characteristics of glottal vibration are affected by the obstruction to the flow of air through the vocal tract system. The obstruction to the airflow is determined by the nature, location, and extent of constriction in the vocal tract during production of voiced sounds. The effects of constriction on glottal vibration are examined for six different categories of speech sounds having varying degree of constriction.

Acoustic analysis of trill sounds.

In this paper, the acoustic-phonetic characteristics of steady apical trills--trill sounds produced by the periodic vibration of the apex of the tongue--are studied. Signal processing methods, namely, zero-frequency filtering and zero-time liftering of speech signals, are used to analyze the excitation source and the resonance characteristics of the vocal tract system, respectively. Although it is natural to expect the effect of trilling on the resonances of the vocal tract system, it is interesting to note that trilling influences the glottal source of excitation as well.