This SHAR volume serves to expand, supplement, and update the original "Cochlea" volume in the series. The book aims to highlight the power of diverse modern approaches in cochlear research by focusing on advances in those fields over the last two decades. It also provides insights into where cochlear research is going, including new hearing prostheses for the deaf that will most likely soon enter the phase of clinical trials. The book will appeal to a broad, interdisciplinary readership, including neuroscientists and clinicians in addition to the more specific auditory community.