Auditory Motion in Motion
Johahn Leung · The Sydney eScholarship Repository (The University of Sydney) · 2016
This thesis describes a number of studies conducted to examine three different facets of horizontal motion processing in the auditory system. Firstly, when a sound moved around a stationary listener (“source motion”); secondly, when subjects engaged in head rotations while sources remained stationary (“self motion”) and lastly when subjects engaged in self motion during simultaneous source motion. Previous studies in the field have explored these issues separately, and much remains unknown. For “source motion”, a localisation based “snapshot” psychophysical model remains the most commonly used narrative in describing this process, given the lack of clarity about the neural pathways underlying motion perception. However, it remains unclear whether (or how) such a framework can generalise to different stimulus conditions. For “self motion”, studies reported here have considered the sensory implications of head motion in the presence of a stationary sound, questioning how auditory spatial perception remains stable and exploring the perceptual benefits from dynamic localisation cues. Yet, the underlying interactions between audition and the head motor plant remain unclear, particularly at the faster head turn velocities. Lastly, there is a scarcity of studies probing the how listeners perceive a moving source during simultaneous self motion, even though it encapsulates concepts in both self and source motion, providing a unique opportunity to help frame our understanding of the sensorimotor mechanisms involved. We addressed these questions with three psychophysical experiments, and proposed a leaky integrative framework as an alternative to the “snapshot” model.