Changes of voice characteristics under noisy conditions: Acoustic and fiberscopic studies of school teachers

Abstract

It has been known that incidence of vocal pathology was high in school teachers as they had to use a great amount of voice and loud phonation in noisy school settings with the children’s loud voices. Vocal hygiene programs and voice therapy are effective treatments for these cases. The final goal of the treatment should be to obtain the skills to use efficient and healthy phonation even in abusive and noisy environments. In our study, two school teachers with vocal nodules, two speech therapists who were trained to keep proper phonation even in noisy environments, and ten college students with no laryngeal pathology (control group) spoke eight sentences in two environments: a quiet environment and one with meaningful multitalker babble (MMB). Acoustic analyses and fiberscopic examination revealed higher sound pressure and F0 levels and laryngeal constriction in MMB for the teachers before therapy and the students, whereas two speech therapists kept similar F0 levels and the nonconstricted laryngeal condition in both environments. A teacher who had voice therapy produced less constricted voice with MMB than the pretherapy recording. The results suggested the efficacy of voice therapy with MMB for teachers to obtain efficient and healthy voice in their noisy work environments.