Effect of pitch and vowels on the quality of resonant voice production

Abstract

Instrumentations have been popular used in investigating the physiology and acoustics of resonant voice that used in voice therapy. However, the factors may affect the quality of resonant voice were seldom controlled that it would reduce the reliability of the measurement. This study investigated the facial bone vibration with pitch and vowels controlled using quantitative measurement during resonant voice production and the perceptual quantification of resonance was used as the reference. It further confirmed the relationship between extent of facial bone vibration and the perceptual quantification of resonance. Fifteen females and 15 males aged from 20 to 30 years with normal voice were given a session of resonant voice training. Vibration measurements using vibro-detectors on the nasal bridge, upper lip and thyroid site were taken. Two speech pathologists with at least 2 years of experience in assessing voice were asked to rate the recorded voices independently using an 11-point equal-appearing interval scale to evaluate the degree of resonance. Results revealed that change of pitch and vowels could affect the measurement of facial bone vibration and proper choice of them could apparently increase the extent of facial bone vibration. Furthermore, with pitch and vowels controlled, the relationship between extent of facial bone vibration and degree of resonance was more regular and evident. These results suggested that proper choice of pitch and vowels would be necessary in resonant voice training and therapy.