Effect of Dysarthria Type, Speaking Condition, and Listener Age on Speech Intelligibility

Abstract

Perceptual outcomes vary across speaking modes, even when speakers with dysarthria are grouped according to similar perceptual profiles. Further investigation of interspeaker differences is needed to inform individually tailored intervention approaches.

Acoustic and perceptual speech characteristics of native Mandarin speakers with Parkinson's disease

“…1,10 The finding of only a weak association between vowel space and intelligibility was of interest. In speakers of English, enhanced vowel space has consistently been associated with intelligibility gain 7,8 -and it appears that the same strength of association did not co-occur, at least for the cohort of participants studied in the current investigation. Therefore, the specific acoustic cues that most strongly influence intelligibility in speakers with PD appear to vary cross-linguistically.…”

“…These findings are consistent with previous studies, which have found that reduced intelligibility is associated with flattened F0 contour at the word level in Mandarin speakers of CP with dysarthria 11 and, furthermore, that compressed VSA is associated with less distinct vowel articulation in speakers of Spanish 3 and English. 7,8 Hence, it is reasonable to conclude that these speech feature might be language-universal features of dysarthria.…”

“…In particular, measures of vowel articulation have been most closely associated with reductions in intelligibility in individuals with PD. 7,8 However, there has been limited investigation of how specific characteristics of hypokinetic dysarthria are linked to speech intelligibility in speakers of languages other than English. This is particularly apparent for Chinese.…”

“…12 Moreover, studies on English speakers with dysarthria have reported a strong association between vowel distinctiveness and speech intelligibility. 7,8 It was predicted that, like English speakers with PD, Mandarin speakers with PD would exhibit vowel centralization, reductions in F0 variation, and a normal to fast speech rate in relation to healthy controls; however, it was anticipated that F0 variation would exhibit the strongest relationship with intelligibility outcomes.…”

Speech Intelligibility in Dysarthrias: Influence of Utterance Length

“…However, in addition to severity of speech impairment, another aspect to be considered in this analysis is the type of dysarthria. The evidence from studies analyzing intelligibility scores in two groups of people with dysarthria, according to type [37] or neurologic disease [15], indicates that the type of the speech disorder could also influence this measure. For example, Tjaden et al [15] described lower sentence intelligibility scores (according to the SIT) for a subgroup of speakers with Parkinson's disease than for a subgroup of speakers with multiple sclerosis, but there were no differences in intelligibility of words measured with the test by Kent et al [3].…”