title: Assessment of the role of the cochlear latency effect in lateralization of click sounds in humans.
abstract: Interaural time and intensity disparities (ITD and IID) are the two cues to sound lateralization. "Time-only" hypothesis claims that an IID is first converted to an interaural afferent delay (Delta t), and is then processed by the central ITD mechanism, rendering a separate IID processor unnecessary. We tested this hypothesis by assessing the contribution of the cochlear latency effect to the psychophysical ITD/IID trading ratio. Auditory brainstem responses (ABRs) were used to measure the interaural afferent delays (Delta ts) that developed with a 20/sec dichotic click train used in the trading experiment. Except for small IIDs at low loudness levels, the physiological Delta t delay produced by an IID was significantly smaller than the ITD psychophysically traded for the same IID. We concluded that the cochlear latency effect alone cannot explain the psychophysical ITD/IID trading ratios and a separate IID mechanism must be involved.
authors.affiliation: Department of Biophysics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
authors.forename: Bülent
authors.initials: B
authors.lastname: Ozmen
authors.forename: Pekcan
authors.initials: P
authors.lastname: Ungan
mesh_terms: D000161:Acoustic Stimulation; D000704:Analysis of Variance; D003051:Cochlea / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D004594:Electrophysiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology