Speech rate effects upon intelligibility and acceptability of dysarthric speech

Abstract

Sentences recorded by four speakers with dysarthria and two control speakers were presented to listeners at three different rates: habitual, a 30% slower rate and a 30% higher rate. Rate changes were made by digitally manipulating the habitual sentences. Thirty young normal adult listeners rated the sentences for intelligibility (per cent correct words) and acceptability (via 9-point equal interval scale ranging from "terrible" through "excellent"). Intelligibility for each speaker remained unchanged across rate changes. Acceptability improved as rates increased for the two more intelligible impaired speakers. For the less intelligible impaired speakers, ratings were better and similar for the habitual and fast speaking rate conditions. Results are discussed in terms of the objective nature of intelligibility ratings vs. the subjective ratings of acceptability.

The Effect of Rate Control on Speech Rate and Intelligibility of Dysarthric Speech

“…None of the alterations were found to be more intelligible than samples produced at habitual SRs. This was confirmed in a study by Dagenais et al [10] , in which intelligibility of dysarthric speech remained unchanged across digitally produced rate changes. Flexible or voluntary RCMs (speaking slower on demand) seem to have a quite varied effect on intelligibility.…”

“…Some studies revealed a positive effect of reduced speech rates on intelligibility in dysarthric speakers [7][8][9][12][13][14] , whereas other studies did not find such an effect [5,[9][10][11] . In the currently investigated dysarthric population, reduced SRs and ARs did not result in higher mean intelligibility ratings.…”

Acoustic and perceptual correlates of faster-than-habitual speech produced by speakers with Parkinson's disease and multiple sclerosis

“…It is noteworthy that a faster-than-habitual rate has been shown to facilitate speech naturalness or speech acceptability at least for some speakers, with or without dysarthria (Dagenais, Brown, & Moore, 2006; Logan, Roberts, Pretto, & Morey, 2002), and these perceptual constructs are strongly associated with intelligibility (see also discussion in Sussman & Tjaden, 2012). The perceptual constructs of speech naturalness or acceptability are further thought to reflect global, suprasegmental aspects of speech (Sussman & Tjaden, 2012).…”

Longitudinal progress of overall intelligibility, voice, resonance, articulation and oromyofunctional behavior during the first 21 months after Belgian facial transplantation

“…Dagenais, Brown, and Moore (2006) described acceptability as the answer to the question, ''How would you rate this person's speaking ability?'' thus emphasizing the notion that speakers might be able to make themselves intelligible, but at the expense of naturalness, marking their speech as atypical but along different parameters from unintelligible speech.…”