Percieved speech severity on prosodic disturbance in speakers with Parkinsons Disease

Abstract

Purpose: To determine if speakers with PD who are perceptually rated as exhibiting moderate-to- severe prosodic impairment exhibit different levels of fundamental frequency variation, as measured using Fo CV, compared to speakers with PD who are perceptually rated as exhibiting less severe prosodic impairment. Also, this study investigated whether male speakers with PD exhibit different levels of Fo CV compared to healthy older male controls. Method: Recordings from 29 speakers with PD were available for prosodic speech severity ratings which determined group membership (e.g., less severe or more severe) while another three recordings, totaling 32 speakers with PD, were available for acoustic analysis to measure the dependent variable of Fo CV. Existing recordings from 21 HOA speakers were also utilized. The recordings utilized in this study consisted of participants producing two speech tasks: (1) oral reading of the CAPE-V sentences, and (2) oral reading of The Rainbow Passage. The middle sentences (the 2nd, 3rd, and 4th sentences) from the Rainbow Passage were used for data analysis. The third CAPE-V sentence, “We were away a year ago”, was used for the sentence analysis. Results: For the perceptually less severe group the statistical findings indicated greater prosodic variability on the CAPE-V sentences compared to the perceptually more severe group. For the comparison of Fo CV as a function of PD vs. HOA male speakers, results suggested that male speakers with PD exhibited significantly less prosodic variability compared to the HOA male in both CAPE-V sentence and Rainbow passage stimuli speakers. Findings of this study also indicated that perceptual severity had a moderate degree of relationship to acoustic measures of prosodic variability for the CAPE-V sentences in speakers with PD.