Self-perception of surface hydration effect on teachers’ voice quality: an intervention study

ABSTRACT Objective: to assess the effects of surface hydration on vocal quality according to teachers’ self-perception. Methods: an examiner-blinded pre-test and post-test intervention study carried out with a single group of 27 teachers. Sociodemographic characteristics and work questionnaire, Screening Index for Voice Disorder, Vocal Severity Rating Scale, Expected Effects Pre-intervention, Perceived Effects Post-intervention and Post-intervention Perception instruments, were applied. The intervention lasted 4 weeks and consisted of 5 minutes of nebulization with saline solution (sodium chloride 0.9%), after 10 minutes of mouth dehydration, prior to teaching. Results: screening Index for Voice Disorder scores demonstrated a statistically significant reduction (p=0.001). Frequency of voice disorders in the Vocal Severity Rating Scale was reduced without a statistical significance (p= 0.172). Expected Effects, Pre-intervention, and Perceived Effects, Post-intervention, showed improvement in vocal quality (40.7%), vocal comfort (40.7%) and vocal folds hydration (37%). Post-intervention perception form showed moderate improvement of the symptoms (59.3%), cleared voice (55.6%) and ease speaking (48.1%) as well as intense belief in the intervention (74.1%) and intense compliance to the intervention (74.1%). Conclusion: surface hydration with saline solution promoted self-perceived improvement in vocal quality.