Effect of vocal loading on voice parameters in trainee actors

Abstract

Introduction: Prolonged use of voice or vocal load can be a risk factor for individuals and can end up in vocal fatigue and dysphonia. Vocal loading can alter tissue structure and affect the voice quality forever. An obvious factor to be considered is the vocal use by a professional voice user. Actors are a group of professionals who can be affected by the long-term use of voice. There is a higher prevalence of inflammatory lesion in acting students and they were found to have poor vocal hygiene habits; which shows that these future elite vocal performers are at risk for developing a voice disorder. Aim: To study the objective and subjective changes in voice characteristics post vocal loading task in trainee actors. Method: A total 37 trainee actors (14 females and 23 males) participated in the study. The age range of the participants were 20 – 39 years and the range of the training period was 6 – 12 months. The participants were instructed to read a passage for 30 – 45 minutes at a loudness level of 70 – 80 dB SPL. Individuals with perceptually normal voice in terms of pitch and intensity and with a score less than 1 in GRBASI (Grade, Roughness, Breathiness, Asthenia, Strain, Instability) rating scale were included in the study. Acoustic, and perceptual evaluation were measured immediately before and after vocal loading task. Acoustic analysis was done using MDVP, whereas The Auditory Perceptual Rating Scale and GRABASI rating scale were used for perceptual analysis. Self-rating of the voice after vocal loading task was measured after the vocal loading task using Vocal Fatigue Index.1 Results and conclusion: The results revealed a significant difference in perceptual parameters post vocal loading task. The f0, jitter and HNR (Harmonic to Noise Ratio) showed a significant increase in the values after the vocal loading task. However, shimmer and RAP (Relative Amplitude Perturbation) did not show significant difference in the values post vocal loading task. The self-rating of the voice after the vocal loading task revealed that 54% of the trainee actors did not perceive vocal fatigue. The study hence shows significant effects of vocal loading in perceptual and acoustic analysis whereas the self-rating shows less perception of vocal changes in training actors. The acoustic, perceptual and self-rating of the voice quality before and after vocal loading task can aid in effective training and management of the trainee actors. However, the actors themselves are not equipped to measure the voice changes acoustically or perceptually and would take much longer time to perceive changes in their voice quality. Therefore, it is important to give a vocal hygiene programme in the preventive stage, that is, in the training period.