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Behavioural And Objective Assessment Of Binaural Hearing In Adult Listeners With Acquired Unilateral Conductive Hearing Loss Before And After Middle Ear Surgery, Parvaneh Abbasalipour

Electronic Thesis and Dissertation Repository

In normally hearing listeners, binaural hearing relies on symmetrical input from the two ears. Previous studies on human listeners have assessed the effect of induced unilateral conductive hearing loss (UCHL) during adulthood via earplugging. These experiments indicated initial difficulty in sound localization followed by gradual improvement due to adaptation to the perturbed binaural cues. The limited duration of earplug use does not represent the consequences of chronic UCHL secondary to disease. Furthermore, there is insufficient information regarding the adaptation of binaural hearing abilities after treatment of late-onset UCHL.

The current study assessed the binaural hearing abilities of adult listeners with …

Identification Of The Smallest Perceivable Interaural Time Differences, Sinthiya Thavam

Electronic Thesis and Dissertation Repository

Several studies have reported human threshold interaural time differences (ITDs) near 10 μs; however, none of these studies aimed to find the stimulus and experimental method that yields the lowest threshold. The goal of the current study is to systematically determine the stimulus and the experimental paradigm that yields the smallest threshold ITD and to provide an accurate reference value. We systematically varied seven parameters: stimulus waveform, stimulus level, stimulus duration, adaptive versus constant stimulus procedure, number of reference intervals, inter-stimulus pause duration, and inclusion versus exclusion of onset and offset ITD. The condition yielding the lowest threshold ITD was …

Effect Of Head Movement On Sound Localization In Real And Simulated Cochlear Implant Users, Kassandra-Anne H. Birtch

Electronic Thesis and Dissertation Repository

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 …