Much of cochlear physiology and pathophysiology remains poorly understood. For example, how do the 3000 rows of active outer hair cells interact with each other and with other cochlear structures to amplify the waves in the cochlea that allow us to hear? How are the motions of these cochlear structures related to the otoacoustic emissions that we can measure in the ear canal? What role do the efferent nerves play? What are the changes brought about by pathology? The long term research goal is to understand human cochlear physiology in both normal and pathological conditions with a view to aiding the development of improved clinical diagnostic techniques and treatments. One approach to improving our understanding of the electro-mechanical aspect of physiology is to develop realistic models of the cochlea. These should capture the essential hydrodynamics, structural dynamics, and electrical processes involved in cochlear physiology. The non-linear mechano-electrical and electro-mechanical transduction processes are key aspects of the physiology where our understanding remains at a basic level. The ways in which these models may be useful clinically are: to aid the development of treatments, or prostheses for hearing impairment, to improve our ability to interpret clinical results (such as measurements of otoacoustic emissions or electrophysiology), to aid the development of new clinical tests of cochlear function.