The Influence of Auditory Processing Difficulties on Perceptual Learning

Understanding spoken language is a complex process that comes to most people easily, yet past research demonstrates that some people face difficulties with auditory processing. Listeners integrate auditory, visual, and other cues to understand speech. However, people with auditory processing difficulties rely less on visual cues, such as lip-reading. We investigated how listeners' reported difficulties in perceiving auditory information interact with their use of visual cues. This was a replication and extension of a study by Kraljic, Samuel, and Brennan (2008). Participants viewed a speaker pronouncing some words in one of four conditions, depending on which phoneme was changed (?S or ?SH) and whether the speaker held a pen-in-hand (characteristic) or had a pen-in-mouth (incidental) while producing these words. We assessed each participant’s phonemic boundaries in a category-identification task, in which participants categorized ambiguous sounds as being more S-like or SH-like. We measured participants' perceptual learning—the restructuring of their phonemic boundaries—based on their categorization of these ambiguous sounds. Afterward, participants were surveyed on their language background and their auditory processing difficulties. We did not replicate the findings on the effect of visual context on perceptual learning from the original study by Kraljic et al. (2008). Contrary to our predictions, we also did not find an effect of individual differences in auditory processing on perceptual learning and no interaction with visual context. Given that the effect of visual context has been replicated before, our results are inconclusive. The effect of individual differences on perceptual learning should be explored further to gain insight into the underpinnings of perceptual learning and how to improve speech perception for those with auditory difficulties.