Perception of novel sounds in the presence of background noise

In everyday experiences, listeners often need to resolve auditory ambiguity of incoming sounds without prior knowledge of the target sound source. When listeners are exposed to an auditory scene with unfamiliar sounds, target sounds are often identified only when they are repeated across non-repeating competing sounds, supporting the idea that repetition provides a basis for segregating a single source from competing novel sounds (Montazeri et al., 2021; McDermott et al., 2011). These results were based on listeners exposed to a repeating target sound with varying distractor sounds during the exposure (i.e., perceptual learning) stage but tested with the target presented in quiet. Our present study extends this by testing whether listeners’ perception of the target sound remains robust when also presented with a novel distractor during the test stage. We found that exposure to a repeating target with either a single distractor or in quiet provided limited benefit for detecting the target with a novel distractor. However, exposure to the target with varying distractors enabled robust recognition against new distractors, suggesting that listeners adapt their expectations to distinguish the target sound only when exposed to varying distractor sounds.