Across-frequency processing of interaural time and level differences in perceived lateralization.

Interaural time and level differences (ITDs and ILDs) contribute to the localization of sound sources; however, reverberation or use of cochlear implants diminishes the role of ITDs. Intracranial lateralization was investigated in normal-hearing listeners using correlated or uncorrelated narrowband noises, where ITDs and/or ILDs from a typical headrelated transfer function were applied. Results showed that ITDs and ILDs contributed to lateralization for correlated noises. ILDs contributed to lateralization for uncorrelated noises. Frequency-dependent ITD and ILD weighting occurred. These data help understand the across-channel processing of ITDs and ILDs, particularly when ITDs may not be available to the listener.