People are remarkably sensitive to the different times that sound waves arrive at their left and right ears. This so-called interaural time difference (ITD) provides important cues for locating sounds, but the neural coding of ITD that gives rise to the perception of sounds in space is not fully understood.

In a study published online on October 12 in eLife, Jose L. Pena, M.D., Ph.D., and Elyse S. Sussman, Ph.D., show that auditory spatial perception and detection of new sounds are spontaneously driven by natural ITD statistics determined by how the head and inner ear filter incoming sounds. The results suggest that the human brain evolved to incorporate natural statistics of spatial cues to the neural code underlying auditory spatial perception. Hearing in particular, and sensory perception in general, appear to be driven by prior information about statistics of the environment. By identifying stimulus parameters that influence auditory spatial perception, the findings could lead to improvements in hearing aids.

Dr. Pena is professor in the Dominick P. Purpura Department of Neuroscience at Einstein. Dr. Sussman is professor in the Dominick P. Purpura Department of Neuroscience and professor of otorhinolaryngology-head & neck surgery at Einstein.