Voice condition assessment and the effect of rehabilitation in vocal professionals

Introduction. The human voice is an important characteristic that enables the distinction of human from other living beings. Otherwise, it represents a picture of a person΄s personality, his health, mental and emotional state. The research aims are to determine the voice characteristics of vocal professionals with diagnosed vocal cord nodules by subjective voice assessment and objective voice measurement before and after vocal rehabilitation. Methods. This study has involved 25 examinees, aged 23 to 56. The subjective voice assessment was conducted with the Voice Handicap Index - VHI questionnaire and the objective voice measurement by a computerized laboratory for voice analysis ''Kay Elemetrics''. The obtained data were processed using descriptive and analytical statistics. Results. Before the vocal rehabilitation and the subjective and objective voice measurements, the examinees had greater psychosocial difficulties associated with their voice quality. After two months of vocal rehabilitation, there has been a significant improvement in the voice of all subjects on the VHI scale. A statistically significant and highly statistically significant improvement have been noticed in six out of seven analyzed parameters of vocal A, by the objective measurement of voice. Namely, the obtained values - the percentage of jitter Jitt (%), the percentage of shimmer Shim (%), the relative average perturbation value RAP (%) and the coefficient of fundamental frequency variation - vFo were highly statistically significant (p < 0.01). The VTI - voice turbulence index and the SPI - soft phonation index also improved, the observed difference was statistically significant (p < 0.05), while the observed difference in the FTRI parameter was not statistically significant (p > 0.05). Conclusion. Vocal rehabilitation has influenced the improvement of the voice quality, which means that the results obtained by objective voice measurements were more in accordance with the results of the subjective voice assessment.