Lindsey N. Van Yper1,2, Juan Pablo Faúndez2, Jaime A. Undurraga2,3, David McAlpine2
1Institute for Clinical Research, University of Southern Denmark, Odense, Denmark
2Department of Linguistics, The Australian Hearing Hub, Macquarie University, Sydney, Australia
3Interacoustics Research Unit, Technical University of Denmark, Lyngby, Denmark

Binaural hearing – particularly the ability to process interaural time differences (ITDs) – underpins sound localization and speech perception in noise. Although ITD processing is known to be affected in various clinical populations, it is not standardly assessed in the clinic, primarily because behavioural measures of ITD are time-consuming and difficult to perform. Recent studies have therefore proposed the ‘acoustic change complex (ACC)’ and ‘interaural-phase modulation following responses (IPM-FR)’ as promising techniques for objective evaluation of ITD processing. Here, we determine the optimal stimulus, recording, and analysis parameters for clinical use of these measurements. Results show that reliable ACC and IPM-FR can be obtained from clinically suitable electrode locations (e.g. mastoids referenced to Cz). However, when using the more practical Fpz location as a reference, one may consider removing eye blinks. We also show that stimulus parameters affect IPM-FR and ACC differently, which may suggest that different neural mechanisms are involved in the generation of these responses.

Acknowledgements: This research has been funded by the Australian Government through the Australian Research Council (project number FL160100108).