Some Physiological Parameters in Speech

Abstract

A series of experiments has shown that: (1) Variations in articulation do not affect the subglottal pressure as long as the vocal cords are vibrating; but in voiceless sounds in which there is a high rate of flow the subglottal pressure is lower than in corresponding phrases with voiced sounds. (2) There is a clear physiological correlate of stress such that nouns of the form insult always have an extra increase in subglottal pressure which occurs earlier than in the corresponding verb forms, irrespective of the intonation pattern. (3) If the set of the vocal cords is not adjusted, an increase of subglottal pressure of about 7 cm. aq. will produce an increase in the frequency of vibration of about half an octave. (4) The variations in the laryngeal factors controlling the frequency of vibration of the vocal cords in utterances are much simpler than the variations in the fundamental frequency; at times the ‘tension of the vocal cords’ may be increasing, although the fundamental frequency is decreasing.