Effects of Resonant Voice Therapy on Perceptual and Acoustic Source and Tract Parameters – A Preliminary Study on Indian Carnatic Classical Singers

Abstract

The aim of the study was to examine the effects of resonant voice therapy (RVT) on the vocal resonance of trained Carnatic singers. The specific objectives were to evaluate the effects of resonant voice therapy on the auditory perceptual judgments and acoustic source and tract parameters before and after RVT on phonation and sung voice samples. Six vocally healthy trained Carnatic singers, three males and three females aged 18-25 years (M=23; S.D=2.09) participated in the study. All the participants were assigned to a 21-days-long Resonance Voice Therapy (RVT) training program. The participants' pre and post training phonation and sung samples were subjected to auditory perceptual analysis and acoustic analysis. The results revealed that the post training auditory perceptual ratings of the phonation task showed a statistically significant difference from the pre training scores (Z= 2.35; P=0.019). While for the singing task, the post training perceptual ratings were not significantly different from the pre training perceptual rating scores (Z= 2.66; P=0.08). A significant difference was observed between the pre and post training values for all the measured acoustic parameters of the phonation task. In singing task, though the fundamental frequency, third and fourth formant frequencies showed no significant difference in the pre and post training conditions (P > 0.05), the parameter of- difference between the first formant frequency and the fundamental frequency showed a significant decrease (P=0.028). The effects of resonant voice production led to a high vocal economy, as evidenced from the improved source and filter acoustic parameters. Indication for formant tuning through vocal tract modifications, probably an enlarged pharyngeal area resulting in increased resonant voice quality in both phonation and singing tasks, is inferred from these results.