Electronic Thesis and Dissertation Repository


Master of Science


Health and Rehabilitation Sciences


Dr. Scott Adams


One of the most prevalent speech impairments in idiopathic Parkinson’s disease (PD) is hypophonia, a reduction in intensity, which typically decreases intelligibility. Speech amplification devices are a potential solution; however, despite the availability of a broad range of devices, no previous studies systematically compare their efficacy in PD. This study examined the effects of speech task (Sentence Intelligibility Test versus conversation), background noise (no noise versus 65 dB SPL multi-talker noise), and selected devices (ADDvox, BoomVox, ChatterVox, Oticon, SoniVox, Spokeman, and Voicette) for 11 PD and 10 control participants, using outcome measures of speech intensity, speech-to-noise ratio, intelligibility, sound quality, and speakers’ experience. There were significant differences between the outcome measures for different device types, but experience scores did not always predict effectiveness according to the device hierarchy for the outcome measures. Future research is needed to determine performance and preference measures that will predict long-term device acceptance in PD.