The role of rhythm in adaptation to dysrhythmic speech, continued

Abstract

Rhythm cues have been shown to be important for deciphering speech in adverse listening conditions, even when the rhythm cues are corrupted. In an initial attempt to document the relationship between rhythm perception and processing of a naturally dysrhythmic speech signal, we found that listeners with expertise in rhythm perception were not advantaged with initial intelligibility of ataxic dysarthria but were significantly advantaged with adaptation to the degraded speech signal [Borrie, Lansford, and Barrett, Journal of Speech, Language, and Hearing Research, 60, 561–570 (2017)]. We speculated that listeners with skills in rhythm perception are better able to exploit experience (familiarization) with the degraded speech, learning something useful about corrupted rhythm cues for subsequent processing. This current study investigated whether the relationship between rhythm perception and perceptual adaptation of dysrhythmic speech, observed in our previous study with ataxic dysarthria, holds for other forms of dysrhythmic speech. Here, we replicate our original study with two different forms of dysarthria: the largely irregular and unpredictable speech of hyperkinetic dysarthria secondary to Huntington’s disease, and the relatively regular and predictable speech of hypokinetic dysarthric speech secondary to Parkinson’s disease. Results will bear on models of dysrhythmic speech perception as well as clinical practice.