Acoustic and Auditory Perception Effects of the Voice Therapy Technique Finger Kazoo in Adult Women

Abstract

This study aimed to verify and to correlate acoustic and auditory-perceptual measures of glottic source after the performance of finger kazoo (FK) technique. This is an experimental, cross-sectional, and qualitative study. We made an analysis of the vowel [a:] in 46 adult women with neither vocal complaints nor laryngeal alterations, through the Multi-Dimensional Voice Program Advanced and RASATI scale, before and immediately after performing three series of FK and 5 minutes after a period of silence. Kappa, Friedman, Wilcoxon, and Spearman tests were used. We found significant increase in fundamental frequency, reduction of amplitude variation, and degree of sub-harmonics immediately after performing FK. Positive correlations were measures of frequency and its perturbation, measures of amplitude, of soft phonation index, of degree and number of unvoiced segments with aspects of RASATI. Negative correlations were voice turbulence index, measures of frequency and its perturbation, and measures of soft phonation index with aspects of RASATI. There was fundamental frequency increase, within normal limits, and reduction of acoustic measures related to presence of noise and instability. In general, acoustic measures, suggestive of noise and instability, were reduced according to the decrease of perceptive-auditory aspects of vocal alteration. It shows that both instruments are complementary and that the acoustic vocal effect was positive.