Interaural level difference cues determine sound source localization by single-sided deaf patients fit with a cochlear implant

Michael Dorman, Daniel Zeitler, Sarah J. Cook, Louise Loiselle, William Yost, George B. Wanna, Rene H. Gifford

Research output: Contribution to journalArticle

22 Scopus citations


In this report, we used filtered noise bands to constrain listeners' access to interaural level differences (ILDs) and interaural time differences (ITDs) in a sound source localization task. The samples of interest were listeners with single-sided deafness (SSD) who had been fit with a cochlear implant in the deafened ear (SSD-CI). The comparison samples included listeners with normal hearing and bimodal hearing, i.e. with a cochlear implant in 1 ear and low-frequency acoustic hearing in the other ear. The results indicated that (i) sound source localization was better in the SSD-CI condition than in the SSD condition, (ii) SSD-CI patients rely on ILD cues for sound source localization, (iii) SSD-CI patients show functional localization abilities within 1-3 months after device activation and (iv) SSD-CI patients show better sound source localization than bimodal CI patients but, on average, poorer localization than normal-hearing listeners. One SSD-CI patient showed a level of localization within normal limits. We provide an account for the relative localization abilities of the groups by reference to the differences in access to ILD cues.

Original languageEnglish (US)
Pages (from-to)183-188
Number of pages6
JournalAudiology and Neurotology
Issue number3
StatePublished - May 28 2015



  • Cochlear implant
  • Interaural level differences
  • Single-sided deafness
  • Sound source localization

ASJC Scopus subject areas

  • Physiology
  • Otorhinolaryngology
  • Sensory Systems
  • Speech and Hearing

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