Immediate ambiguity resolution in speech perception based on prior acoustic experience Laura Gwilliams & Pascal Wallisch Department of Psychology New York University Abstract Speech perception relies on the rapid resolution of uncertainty. Here we explore whether auditory experiences contribute to this process of ambiguity resolution. ~8000 participants were surveyed online for their (i) subjective percept of a speech stimulus with ambiguous formant allocation; (ii) demographic profile and auditory experiences. Both linguistic and non-linguistic auditory experiences significantly predict speech perception. Listeners were more likely to perceive the ambiguous stimulus in accordance with their own name, and were biased towards lower formant allocation as a function of being exposed to lower auditory frequencies in their environment. Overall, our results show that the subjective interpretation of an ambiguous stimulus in the auditory domain is determined by prior acoustic exposure, suggesting the operation of an exposure-dependent mechanism impacting sensitivity that resolves ambiguity in speech perception. Significance statement Organisms must contend with fundamental uncertainty due to missing information in sensory inputs, resulting in perceptual ambiguity. There are several known ways in which perceptual ambiguity of speech is resolved, most importantly by the immediate linguistic context. Here, we show that prior acoustic experience - be it speech specific or more general - determines how listeners resolve a segment of ambiguous speech, the LaurelYanny stimulus. This is important both because it suggests that the brain uses the principle described in this paper to resolve ambiguous speech in general and that divergent auditory inputs will yield immediate disagreement about the conscious percept, given ambiguous stimulus situations. Keywords: speech, ambiguity resolution, formant, auditory, perception, disagreement, #LaurelYanny