1. An object detection and notification system of an autonomous vehicle, comprising: an object detection system that detects a presence of a target object within a sensing range of one or more sensors of the object detection system and determines a direction of travel of the target object relative to the autonomous vehicle based on the detection of the presence of the target object from the one or more sensors; a notification system that provides a sound cue using a speaker to an occupant of the autonomous vehicle that is indicative of a location of the target object relative to the autonomous vehicle based on the detection of the presence of the target object from the one or more sensors; and an occupant monitoring device that provides information indicative of a viewing angle of the occupant that is used by the object detection and notification system to provide the sound cue; wherein the notification system localizes the sound cue to a calculated angle based on the viewing angle of the occupant and moves a perceived location of the localized sound cue in a spatio-temporal fashion in stages increasingly toward a desired viewing angle based on the direction of travel of the target object.