Ruth Y. Litovsky
1Waisman Center, University of Wisconsin, Madison, USA
2Communication Sciences and Disorders, University of Wisconsin, Madison, USA

Our work focuses on patients with bilateral deafness who are eligible to receive bilateral cochlear implants (BiCIs), and patients with single-sided deafness who receive a cochlear implant (SSD-CI) in the deaf ear. In both the BiCI and SSD-CI populations there is a potential benefit from the integration of inputs arriving from both ears. Benefits include improved ability to localize sounds and to segregate speech from background noise, compared with unilateral listening. However, patients typically perform worse than normal hearing listeners. We use several approaches to understand mechanisms driving gaps in performance. We assess their ability to process auditory cues that are most essential for spatial hearing, and the role of age and auditory experience. We also use research processors to test novel stimulation paradigms designed to restore binaural sensitivity and speech understanding in noise. Our studies provide evidence for the role of auditory plasticity in driving binaural hearing. In addition, patients report that bilateral hearing reduces their cognitive load and fatigue, but few studies have addressed this issue. Pupillometry studies and also functional near infrared spectroscopy might be used as objective tools that can provide insight into the impact of integrating inputs from two ears, whereby in some instances improved performance with two ears can be “costly” in the listening effort domain.

Acknowledgements: The work was conducted in collaboration with Lukas Suveg, Emily Burg, Tanvi Thakkar, Shelly Godar, Ellen Peng, Alan Kan and Dan Lee. NIH-NIDCD (R03DC015321 to AK and R01DC003083 to RYL), and NIH-NICHD (U54HD09256 to Waisman Center).