Project Summary Spatial navigation is a complex task that requires sensory processing, integration, and the creation of a spatial map. Our project seeks to understand the role of auditory cues in spatial navigation. Traditionally, auditory landmarks have been ignored with scientists looking instead at visual, vestibular, and proprioceptive cues. New behavioral studies point to a human ability to use auditory landmarks in self-motion perception, balance, and gait. Here, we seek to understand the role of auditory spatial landmarks in spatial navigation, assessed by careful experimental manipulation of available sensory cues (auditory, visual, and self-motion cues) during a homing task. We propose two aims to examine the role of audition in spatial navigation. In our first aim, we seek to quantify how audition is integrated with other senses for human spatial encoding and navigation. We propose to examine this in the framework of the maximum likelihood computational model (termed optimal cue-combination model). We hypothesize that humans will use auditory information in an optimal manner, though auditory information will contribute less to the spatial map than visual cues or self-motion cues. In the second aim, we propose to examine the relative weight that individuals with sensory loss place on auditory information. We plan to do this with virtual reality simulations of visual and self-motion sensory impairment in the acute setting. We also plan to examine how individuals having a chronic sensory loss (longstanding low vision or vestibular asymmetry) weight auditory landmarks for navigation. The proposed work will have a significant impact on the field of multisensory integration and help generate potential new rehabilitation strategies for individuals suffering from sensory impairment.