BACKGROUND : As a professional voice user, it is imperative that a speech-language pathologist’s
(SLP) vocal effectiveness remain consistent throughout the day. Many factors may contribute
to reduced vocal effectiveness, including prolonged voice use, vocally abusive behaviours,
poor vocal hygiene and environmental factors.
OBJECTIVES : To determine the effect of service delivery on the perceptual and acoustic features
METHOD : A quasi-experimental., pre-test–post-test research design was used. Participants
included third- and final-year speech-language pathology students at the University of Pretoria
(South Africa). Voice parameters were evaluated in a pre-test measurement, after which the
participants provided two consecutive hours of therapy. A post-test measurement was then
completed. Data analysis consisted of an instrumental analysis in which the multidimensional
voice programme (MDVP) and the voice range profile (VRP) were used to measure vocal
parameters and then calculate the dysphonia severity index (DSI). The GRBASI scale was
used to conduct a perceptual analysis of voice quality. Data were processed using descriptive
statistics to determine change in each measured parameter after service delivery.
RESULTS : A change of clinical significance was observed in the acoustic and perceptual
parameters of voice.
CONCLUSION : Guidelines for SLPs in order to maintain optimal vocal effectiveness were