Improved Estimation of Parkinsonian Vowel Quality through Acoustic Feature Assimilation.

This paper investigated the performance of a number of acoustic measures, both individually and in combination, in predicting the perceived quality of sustained vowels produced by people impaired with Parkinson's disease (PD). Sustained vowel recordings were collected from 51 PD patients before and after the administration of the Levodopa medication. Subjective ratings of the overall vowel quality were garnered using a visual analog scale.

A Comparison of Speech Amplification and Personal Communication Devices for Hypophonia.

Purpose This study compared the performance of three amplification devices hypothesized to improve speech communication in individuals with hypophonia (HP), as well as to identify individuals' device preferences. Method Twenty-two individuals with HP and their primary communication partners participated in a cross-over design study comparing three different speech amplification devices: a wired portable amplifier (Device A), a wireless stationary amplifier (Device B), and a one-way personal communication system (Device C). Participants attended one laboratory visit followed by 1-week trial periods with each device.

Voice quality severity and responsiveness to levodopa in Parkinson's disease.

The effect of levodopa on perceptual and acoustic measures of voice quality was examined in fifty-one individuals with Parkinson's disease (IWPD). IWPDs produced prolonged vowels while on and off levodopa. Acoustic measures included jitter, shimmer, harmonic-to-noise ratio, cepstral peak prominence and the Acoustic Voice Quality Index.