title: Changes in teachers' voice quality during a working day with and without electric sound amplification.
abstract: The present study investigated changes in the voice quality of teachers during a working day (a). in ordinary conditions and (b). when using electrical sound amplification while teaching. Classroom speech of 5 teachers was recorded with a portable DAT recorder and a head-mounted microphone during the first and the last lesson of a hard working day first in ordinary conditions and the following week using amplification. Long-term average spectrum and sound pressure level (SPL) analyses were made. The subjects' comments were gathered by questionnaire. Voice quality was evaluated by 2 speech trainers. With amplification, SPL was lower and the spectrum more tilted. Voice quality was evaluated to be better. The subjects reported less fatigue in the vocal mechanism. Spectral tilt decreased and SPL increased during the day. There was a tendency for perceived asthenia to decrease. No significant changes were observed in ordinary conditions. The acoustic changes seem to reflect a positive adaptation to vocal loading. Their absence may be a sign of vocal fatigue.
authors.affiliation: Teacher's Training Department, University of Akureyri, Akureyri, Iceland. valdisj@ismennt.is
authors.forename: Valdis
authors.initials: V
authors.lastname: Jónsdottir
authors.forename: Anne-Maria
authors.initials: AM
authors.lastname: Laukkanen
authors.forename: Ilona
authors.initials: I
authors.lastname: Siikki
mesh_terms: D000669:Amplifiers, Electronic; D005178:Faculty / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013061:Speech Acoustics; D014832:Voice Disorders / Q000150:complications* / Q000453:epidemiology* / Q000209:etiology*; D014833:Voice Quality; D016526:Workload