Assessment of the Contribution of the Combined Acoustic Hearing Via a Hearing Aid and Electric Hearing Via a Cochlear Implant in Adult Bimodal Users With Moderate to Severe Residual Hearing in the Implanted and Non Implanted Ear.

Many current unilateral Cochlear Implant users have some residual acoustic hearing in the opposite ear as well as in the implanted ear. The amount of useful residual acoustic hearing varies among these implantees. There are several acoustic and electric combinations in the bilateral-bimodal listening mode depending on the amount of useful residual acoustic hearing in each ear. The combination of low frequency acoustic information provided by the hearing aid on each ear, completes the high frequency electric information provided by the Cochlear Implant (complementary bimodal benefit). Each of the different rehabilitation combinationsfor unilateral Cochlear Implant users enablesa unique integration of the three aspects of bilateral hearing bilaterality, binaurality and bimodality which may provide significant advantages over unilateral Cochlear Implant stimulation in terms of speech perception in noise, complementary information as well as localization abilities.

The study will include 20 bilateral-bimodal users with moderate-to-severe hearing loss at 250 Hz, 500 Hz and 1000 Hz in the non-implanted ear, who use hearing aids for at least 75% of their waking hours. Evaluation utilizes bilateral-binaural and bimodal complementary effects task-specific test batteries based on published doctoral research project. The assessment protocol consisted of tests that include various speech materials, different maskers, presentation of the noise from different locations in space, right/left speech lateralization, pitch-related tasks and subjective questionnaires. All tests will be administered in three listening conditions: Cochlear Implant -alone, hearing aid-alone and Cochlear Implant +hearing aid.