A number of studies have been devoted to the examination of clear versus conversational speech in non-impaired speakers. The purpose of these previous studies has been primarily to help increase speech intelligibility for the benefit of hearing-impaired listeners. The goal of the present study was to examine differences between conversational and clear speech in individuals with Parkinson disease (PD). Twelve individuals were recorded producing conversational and clear speech. Acoustic analysis revealed that individuals with PD used some of the same clear speech strategies used by non-impaired speakers. Specifically, clear speech in PD was characterized by decreased articulation rate, increased mean fundamental frequency (F(o)), and increased speaking F(o)S.D. compared to conversational speech. The discussion examines the possibility that individuals with PD may have been independently applying a clear speech strategy based on their habitually increased percent pause values. Discussion also focuses on implications of the present findings to management of individuals with PD, and research implications.
Learning outcomes: As a result of this activity, the participant will be able to (1) describe the characteristics of clear speech produced by non-disordered individuals, (2) describe the acoustic characteristics of clear and conversational speech produced by individuals with Parkinson disease; and (3) describe the strategies individuals with Parkinson disease use when asked to produce clear speech.