The proposed research is an evaluation of spectral locus and temporal stimulus factors as they affect several aspects of binaural information processing. One area of concern is the laterality of the images generated by signals with interaural differences of time (as seen in the envelope and/or microstructure) and intensity. Narrow bands of noise and sinusoidally-amplitude-modulated tones will allow separate parametric control of these stimulus features. An """"""""acoustic pointer"""""""" is proposed as a means by which listeners can report the positions of perceived images. A prime motivation for this research is contained in preliminary data which show easily-detectable interaural differences in high-frequency stimuli generating only small image displacements. A second subset of experiments will use the lateral position data as calibration for a study of sensitivity to interaural differences in off-midline stimuli, again examining both varieties of temporal disparities and undertaking a major attempt to examine intensitive disparities in isolation. Finally, we will look at detectability and lateralization in the context of a single experiment that attempts to separate those stimulus aspects which merely are detectable when interaurally-discrepant from those which cause image movement. In addition to contributing to our understanding of normal hearing, this program of research should also elucidate how people with sensorineural hearing losses process sounds binaurally.
