Neural Coding and Auditory Perception

The long-term goal of this project is to understand the neural mechanisms that mediate the ability of normal-hearing people to understand speech and localize sounds in complex acoustic environments comprising reverberation and competing sound sources. In the past year, we focused on two research projects: (1) Physiological and psychophysical studies of sound localization in reverberant environments (Aim 1); (2) Spatio-temporal representation of pitch in the auditory nerve and cochlear nucleus (Aim 2). Sound localization in reverberant environments: Relating neural responses to human perception Reverberation, which is ubiquitous in everyday listening environments, poses a challenge to sound localization. In reverberant rooms, acoustic reflections interfere with the direct sound, leading to pronounced fluctuations in interaural differences in time (ITD) and level (ILD) over the course of a stimulus. These effects become more severe as the distance from sound source to listener increases, which causes the ratio of direct to reverberant energy (D/R) to decrease. We conducted two parallel studies aimed at characterizing the influence of acoustic reflections occurring in typical classrooms on both the directional sensitivity of low-frequency ITD-sensitiv