Comparison of respiratory competency based on MPT and S/Z ratio in teachers with/without voice disorders risk based on SIVD

The respiratory system is considered as a source of energy for normal vibration of vocal folds with no extra forces on external and internal laryngeal muscles. This system is specifically important in professional voice users. With regard to the high incidence of voice problems among teachers, as a significant group of professional voice users, the present study was conducted to investigate the respiratory competency using MPT and s/z Ratio criterion in teachers with and without voice problems risks classified based on their scores on Screening Index for Voice Sisorder (SIVD).
The current cross-sectional study was carried out on 100 elementary school teachers. The participants first completed the SIVD questionnaire, and then the MPT and the s/z Ratio were calculated for each teacher. Data analysis was run using SPSS (v. 18).
No significant difference was observed between means of MPT and s/z Ratio in male participants in the two groups. However, the difference between means of MPT in female participants was found to be significant (p= 0.01).
The results suggest that although respiratory competency was lower than normal in all the teachers, it cannot solely be the cause of developing the risk of voice problems.