Enrique A. Lopez-Poveda, Ph.D. is director of the Auditory Computation and Psychoacoustics Unit of the Neuroscience Institute of Castilla y León (University of Salamanca, Spain). His research focuses on understanding and modeling human cochlear nonlinear signal processing and the role of the peripheral auditory system in normal and impaired auditory perception. He has authored over 45 scientific papers and book chapters and is co-editor of the book Computational Models of the Auditory System (Springer Handbook of Auditory Research). He has been principal investigator, participant and consultant on numerous research projects. He is member of the Acoustical Society of America and of the Association of Research in Otolaryngololgy.   Alan R. Palmer, Ph.D. is Deputy Director of the MRC Institute of Hearing Research and holds a Special Professorship in neuroscience at the University of Nottingham UK. He received his first degree in Biological Sciences from the University of Birmingham UK and his PhD in Communication and Neuroscience from the University of Keele UK.  After postdoctoral research at Keele, he established his own laboratory at the National Institute for Medical Research in London.  This was followed by a Royal Society University Research Fellowship at the University of Sussex before taking a program leader position at the Medical Research Council Institute for Hearing Research in 1986.  He heads a research team that uses neurophysiological, computational and neuroanatomical techniques to study the way the brain processes sound.   Ray Meddis, Ph.D. is director of the Hearing Research Laboratory at the University of Essex, England. His research has concentrated on the development of computer models of the physiology of the auditory periphery and how these can be incorporated into models of psychophysical phenomena such as pitch and auditory scene analysis. He has published extensively in this area. He is co-editor of the book Computational Models of the Auditory System (Springer Handbook of Auditory Research). His current research concerns the application of computer models to an understanding of hearing impairment. He is a fellow of the Acoustical Society of America and a member of the Association of Research in Otolaryngololgy.