摘要：SummarySounds reach the ears as a mixture of energy generated by different sources. Listeners extract cues that distinguish different sources from one another, including how similar sounds arrive at the two ears, the interaural coherence (IAC). Here, we find listeners cannot reliably distinguish two completely interaurally coherent sounds from a single sound with reduced IAC. Pairs of sounds heard toward the front were readily confused with single sounds with high IAC, whereas those heard to the sides were confused with single sounds with low IAC. Sounds that hold supra-ethological spatial cues are perceived as more diffuse than can be accounted for by their IAC, and this is accounted for by a computational model comprising a restricted, and sound-frequency dependent, distribution of auditory-spatial detectors. We observed elevated cortical hemodynamic responses for sounds with low IAC, suggesting that the ambiguity elicited by sounds with low interaural similarity imposes elevated cortical load.Graphical abstractDisplay OmittedHighlights•Listeners report ambiguous spatial percepts for sounds with reduced interaural coherence•Supra-ethological spatial cues impose an additional diffuse quality to sounds•A frequency-dependent distribution of spatial detectors explains behavioral results•Sounds with low interaural coherence impose elevated cortical loadBiological sciences; Neuroscience; Sensory neuroscience
