Abstract:
STATE OF THE ART : Theater actors are a high risk group for developing voice disorders.
AIMS : The first purpose of this study was to examine and compare the objective and subjective vocal quality between professional theater actors, non-professional theater actors and a control group of professional dancers. Secondly, the impact of one theater performance on the objective and subjective vocal quality was investigated within and between the groups. It is hypothesized that actors will experience vocal fatigue and a deteriorated vocal quality compared with dancers as a result of the vocal load during the performance. Dancers will face more general fatigue and smaller vocal changes due to the impact of a performance including stress, decompensation and physical fatigue.
METHODS : Recordings of 27 professional actors, 19 non-professional actors and 16 professional dancers were collected before and after a performance using the PRAAT software. Voice samples included sustained vowel phonation, continuous speech, aerodynamic measurements and voice range profile. Both Acoustic Voice Quality Index and Dysphonia Severity Index were computed. For auditory-perceptual evaluations the GRBASI scale was used. Several questionnaires were completed pre and post performance to capture vocal risk factors.
RESULTS : Vocal quality between groups showed lower fundamental frequency (fo) values (female), larger fundamental frequency (female) and intensity ranges and a longer maximum phonation time (female) in professional actors compared to non-professionals. Professional dancers showed higher Acoustic Voice Quality Index values compared to non-professional actors. Dysphonia Severity Index, Voice Handicap Index, Vocal Tract Discomfort Scale and GRBASI results did not differ between groups at the baseline. Both objective measurements and questionnaires did not show significantly different results post performance. Questionnaires revealed poor vocal habits in professional actors.
CONCLUSION : Professional actors have better vocal capacities than non-professionals. Dancers’ vocal quality is worse than actors. The results show no impact of one performance on the vocal quality in theater actors and dancers. The long-term impact of performing, however, is subject for further research.
