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The Effect of Surface Hydration on Teachers' Voice Quality: An Intervention Study
Émile Rocha Santana1, Maria Lúcia Vaz Masson2, Tânia Maria Araújo3
1Master Program of Health, Environment and Work, Federal University of Bahia (PPGSAT-UFBA), Salvador, Brazil; Undergraduate Program of Speech, Language and Hearing Sciences, União Metropolitana para Educação e Cultura University (UNIME), Lauro de Freitas, Brazil.
Purpose:
This study aimed to investigate the effects of surface hydration on teachers' voice quality.
Study Design:
This is an examiner-blinded, pretest and posttest intervention study with a single group of subjects.
Method:
Subjects were 27 teachers from a public-sector state school in Salvador, Bahia, Brazil. Pre- and post-intervention voice recordings were obtained. Voice samples collected underwent computerized acoustic analysis (VoxMetria) and perceptual analysis via the Consensus Auditory-Perceptual Evaluation of Voice. Intervention was conducted daily before teaching for a 4-week period, consisting of 5 minutes of nebulization with saline solution (NaCl 0.9%), after 10 minutes of dehydration breathing through the mouth.
Results:
A reduction in the overall level of voice alteration was observed in the Consensus Auditory-Perceptual Evaluation of Voice, but with no statistical significance. The following were observed: an increase in the mean fundamental frequency of the vowel /a:/ (P = 0.036); a statistically significant reduction in the minimum intensity of connected speech (P = 0.028), in the median intensity of connected speech (P = 0.014), and in the maximum intensity of connected speech (P = 0.007). There was also a statistically significant reduction in the minimum (P = 0.001) and mean intensities of spontaneous speech (P = 0.011).
Conclusion:
Surface hydration with saline solution led to an improvement in teachers' voice quality.
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