The Neural Engineering for Speech and Hearing Laboratory examines how the brain processes sound through psychophysical, physiological and computational modeling experiments. We focus in particular on the experience of people with hearing loss who use cochlear implants, electronic devices that function as the inner ear by sending sound signals to the brain. While these implants work well in quiet settings, they are much less effective in situations with background noise. Normal-hearing listeners overcome this hurdle by tracking quality differences between target voice and background interference, easily distinguishing, for example, between men’s and women’s voices. By contrast, cochlear implant users have poor pitch sensitivity and typically can’t make these distinctions. Why is this gap critical? The inability to hear in daily social settings — restaurants, meetings and parties — can lead to isolation and depression. A recent landmark study showed it also causes cognitive decline. We aim to identify the behavioral and neuronal mechanisms for hearing disruption caused by background noise to advance our understanding of how hearing loss affects the capacity to ignore competing sounds — and to develop remediation strategies that will improve cochlear implants.