Voice amplification in the education field: A literature review

Abstract

Introduction: Voice amplifiers have been used as tools to prevent voice disorders in teachers. Objectives: To know reported changes in vocal behavior when teachers use voice amplification systems and to make a comparison before and after their use. Materials and methods: A review of articles was carried out in four databases and 11 were selected following inclusion and exclusion criteria; the level of evidence was IIb in 3 of them and IV in 8. The information of the articles was analyzed to collect data on the effects on perceptual and acoustic vocal behavior versus the use of voice amplification. Results: The participants showed a decrease in the intensity and fundamental frequency, with greater effects on the population without a speech disorder. There was a significant decrease in the distance dose as opposed to the cycle dose. A decrease in symptoms was inferred from the questionnaires, as well as a reduction of vocal load and improvement in communication. Conclusion: Voice amplifiers are a tool for preventing voice disorders. Future research should be more rigorous regarding the levels of evidence and include a study design that allows obtaining consistent results in different voice users.