Assessment of the role of the cochlear latency effect in lateralization of click sounds in humans


Ozmen B., Ungan P.

PSYCHOPHYSIOLOGY, vol.46, no.4, pp.797-806, 2009 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 4
  • Publication Date: 2009
  • Doi Number: 10.1111/j.1469-8986.2009.00828.x
  • Journal Name: PSYCHOPHYSIOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Social Sciences Citation Index (SSCI), Scopus
  • Page Numbers: pp.797-806
  • Hacettepe University Affiliated: Yes

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.