Vibratory and perceptual measurement of resonant voice

Abstract

INTRODUCTION: Resonant voice is a commonly used vocal facilitative technique for treating individuals with phonotraumatic injuries. Traditionally, auditory perceptual evaluation is used to judge the degree of resonance during resonant voice production. The present study investigated whether there existed a correlation between auditory perceptual rating of resonant voice and the physical vibration in the facial bone. It also compared the magnitude of facial bone vibration in three types of voice production (resonant versus non-resonant versus strained voices). METHOD: Thirty-six vocally healthy individuals were given a session of resonant voice training. Piezoelectric accelerometers were used to measure the vibrations over the nasal bridge and in the peri-laryngeal area during resonant voice production. Seventy-two sounds (/ma/) under resonant voice condition by these speakers were selected and rated by two experienced speech pathologists to evaluate the amount of phonatory resonance using an 11-point equal appearing interval scale. The magnitude of facial bone vibration among the three voice types was compared as well. RESULTS: Results indicated significant moderate correlation between the nasal bone vibration and the auditory perceptual rating of phonatory resonance (Spearman rho=0.6, p<0.0001). Compare to the non-resonant and strained voice, resonant voice has a significant increase (p<0.05) in the magnitude of facial bone vibration. DISCUSSION: These results suggested that piezoelectric accelerometer can be used as a noninvasive tool to quantitatively and reliably measure the extent of bone vibration during resonant voice production. It is more useful than the auditory perceptual rating per se in determining the extent of resonance.