Effect of Head Movement on Sound Localization in Real and Simulated Cochlear Implant Users

Cochlear implant (CI) users’ limited ability to use acoustical cues for sound localization causes left/right confusions and front/back reversals. Head movement is beneficial in reducing these errors in acoustically hearing listeners. This study investigated the effect of head movement on localization throughout 360o of azimuth for both real and simulated CI users. Listeners in a bilateral electro-acoustic (CI with ipsilateral hearing aid) simulation derived the greatest head movement benefit in reducing front/back reversals. Left/right confusions were reduced in simulations with matched bilateral stimulation. Sensitivity to both timing and level cues for sound localization was correlated with sound localization performance without head movement for simulated device users. Sensitivity to timing cues was correlated with sound localization performance with head movement cues for simulated device users. Simulations of bilateral CI and bimodal users (CI with contralateral hearing aid) listening predicted real users’ sound localization performance, binaural sensitivity and head movement patterns