Testing a Model for Supernormal Auditory Localization

Previous experiments have concluded that better-than-normal performance in localization could be achieved with "supernormal" auditory localization cues; however, different exposure conditions during training (e.g., the presence or absence of visual cues) affected the subjects' ability to adapt. This study was undertaken to determine which intersensory effects are necessary and sufficient to achieve adaptation to the altered supernormal cues. Previous experiments have concluded that adaptation (decrease in bias with extended exposure to transformed auditory localization cues) is achieved when explicit visual cues are presented during training. In those experiments, correct answer feedback was provided through the lights in the visual display. When all visual information (explicit visual cues and the visual field) is eliminated using blindfolds, subjects showed no adaptation. The current study concludes that the visual field can be used to reference head position during training. This information is sufficient to achieve adaptation. Therefore, the visual field is important and useful in achieving adaptation to transformed auditory localization cues. Thesis Supervisor: Nathaniel I. Durlach Title: Senior Research Scientist