For young people with healthy hearing, listening to speech is often effortless and something that one can take for granted. However, as one ages, and for people with a hearing loss, speech perception is challenging and can impact education, employment, and mental health. I lead a research group at the CBU that investigates the basic processes of both healthy hearing and that experienced by profoundly deaf people whose hearing has been restored by a cochlear implant (CIs). Our research with normal-hearing listeners investigates questions such as how we hear pitch, what physical cues the brain can and cannot use to separate competing sounds, and how sound segregation is affected by attention, linguistic knowledge, and what the listener wants to hear. Our research with CIs builds on their remarkable success at restoring hearing to more than 800,000 people worldwide, and investigates the biological limitations of CI hearing. We employ a wide range of behavioural, electrophysiological, and imaging techniques and to understand the neural bases for perception and to improve hearing for CI listeners.