Task-dependent consequences of disfluency in perception of native and non-native speech

Silent pauses are a natural part of speech production and have consequences for speech perception. However, studies have shown mixed results regarding whether listeners process pauses in native and non-native speech similarly or differently. A possible explanation for these mixed results is that perceptual consequences of pauses differ depending on the type of processing that listeners engage in: a focus on the content/meaning of the speech versus style/form of the speech. Thus, the present study examines the effect of silent pauses of listeners' perception of native and non-native speech in two different tasks: the perceived credibility and the perceived fluency of the speech. Specifically, we ask whether characteristics of silent pauses influence listeners' perception differently for native versus non-native speech, and whether this pattern differs when listeners are rating the credibility versus the fluency of the speech. We find that while native speakers are rated as more fluent than non-native speakers, there is no evidence that native speakers are rated as more credible. Our findings suggest that the way a non-native accent and disfluency together impact speech perception differs depending on the type of processing that listeners are engaged in when listening to the speech.