Vowel focused training improves listener transcription of dysarthric speech

Abstract

Typical listeners can adjust to the speech of individuals with dysarthria through the process of perceptual learning. Past research has demonstrated that listeners improve in their recognition of both segments and connected speech produced by people with dysarthria. The mechanisms underlying learning of dysarthric speech are still uncertain, though it has been suggested that exposure allows listeners to tune into the segmental characteristics of speech. In the current study, we test this hypothesis by training listeners to identify vowels spoken by an individual with mild dysarthria. We employed a pre-test/post-test design where we first tested listeners on (1) vowel recognition and (2) transcription accuracy of connected speech, trained them, and then tested them again. We found that listeners who were trained on dysarthric vowels demonstrated greater improvements in vowel identification than those in the control condition. Likewise, the listeners who underwent training showed greater improvements in transcription accuracy than those in the control condition. However, the training advantage did not generalize to unfamiliar phrases. Overall, it appears that listeners are able to tune into the segmental characteristics of dysarthric speech after a short training session, which improves their recognition of longer connected speech.