Sound source history warps perceived azimuth and elevation

In real-world auditory localization, humans make decisions based on acoustic cues that reach the ear as well as from expectations of where the sound may originate. Past studies have shown that the auditory system makes rapid adjustments in response to changes in the statistics of recent stimulation, which help maintain sensitivity over the range where most stimuli occur. In the current study, we explored the auditory system’s adaptability and plasticity by presenting sounds in different spatial contexts and examined the subsequent effects on sound localization accuracy. Identical sounds were rendered at different azimuth and elevation ranges of [−15°, −30°, 0°] or [15°, 30°, 0°] presented in contextual blocks. Sounds presented at 0° azimuth exhibited a rightward shift in perception when the targets were blocked within the left hemispace, and a leftward shift when targets were blocked in the right hemispace. Sounds that were blocked in the bottom hemispace showed an upward bias in perceived elevation, although the reverse was not found to be significant. Furthermore, participants who showed more errors in overall localization showed a higher degree of bias. Our results corroborate the account that the mapping of auditory space is dynamic and shifts depending on the context in which sounds are presented.