The Cochlea

Knowledge about the structure and function of the inner ear is vital to an understanding of vertebrate hearing. This volume presents a detailed overview of the mammalian cochlea from its anatomy and physiology to its biophysics and biochemistry. The nine review chapters, written by internationally distinguished auditory researchers, provide a detailed and unified introduction to sound processing in the cochlea and the steps by which the ensuing signals are prepared for the central nervous system.

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.

Millions of Americans experience some degree of hearing loss. The Social Security Administration (SSA) operates programs that provide cash disability benefits to people with permanent impairments like hearing loss, if they can show that their impairments meet stringent SSA criteria and their earnings are below an SSA threshold. The National Research Council convened an expert committee at the request of the SSA to study the issues related to disability determination for people with hearing loss. This volume is the product of that study. Hearing Loss: Determining Eligibility for Social Security Benefits reviews current knowledge about hearing loss and its measurement and treatment, and provides an evaluation of the strengths and weaknesses of the current processes and criteria. It recommends changes to strengthen the disability determination process and ensure its reliability and fairness. The book addresses criteria for selection of pure tone and speech tests, guidelines for test administration, testing of hearing in noise, special issues related to testing children, and the difficulty of predicting work capacity from clinical hearing test results. It should be useful to audiologists, otolaryngologists, disability advocates, and others who are concerned with people who have hearing loss.

Today cochlear implants are the most successful of all prostheses of the nervous system. They are used in individuals who are deaf or suffer from a severe hearing deficiency caused by loss of cochlear hair cells. Auditory brainstem implants provide stimulation of the cochlear nucleus and are used in patients with an auditory nerve dysfunction, a deformed cochlea which does not allow cochlear implantation, or traumatic auditory nerve injury. In this volume different aspects of cochlear implantation such as the role of neural plasticity, the interaction with the development of the auditory system, and the optimal time of implantation in children (sensitive periods) are discussed in detail. Further, the processors and the algorithms used in modern cochlear implants are described The second part is devoted to auditory brainstem implants. It describes surgical techniques, methods for intraoperative testing as well as speech processing. It also deals with electrical stimulation of neural tissue and the neurophysiologic basis for cochlear and brainstem implants. The publication provides the latest scientific and clinical knowledge on cochlear and brainstem implants and is highly recommended to audiologists, otolaryngologists and also neurosurgeons.

The field of cochlear mechanics has received an increasing interest over the last few decades. In the majority of these studies the researchers use linear systems analysis or linear approximations of the nonlinear (NL) systems. Even though it has been clear that the intact cochlea operates nonlinearly, lack of tools for proper nonlinear analysis, and widely available tools for linear analysis still lead to inefficient and possibly incorrect interpretation of the biophysics of the cochlea. An example is the presumption that a change in cochlear stiffness at hair cell level must account for the observed change in tuning (or frequency mapping) due to prestin application. Hypotheses like this need to be addressed in a tutorial that is lucid enough to analyze and explain basic differences. Cochlear Mechanics presents a useful and mathematically justified/justifiable approach in the main part of the text, an approach that will be elucidated with clear examples. The book will be useful to scientists in auditory neuroscience, as well as graduate students in biophysics/biomedical engineering.

This book contains the proceedings of an international hearing-research conference held in Germany 2002. The conference brought together experts in genetics, molecular and cellular biology, physiology, engineering, physics, mathematics, audiology and medicine to synthesize and extend our understanding of how the cochlea works. Topics are discussed experimentally and theoretically at the molecular, cellular and whole-organ levels. Some of the topics are: mechanosensitivity of motor proteins; mechanochemical transduction by motor proteins; mechanoelectrical transduction in the stereocilia of hair cells; electromechanical transduction in the stereocilia, soma and synapses of hair cells; multidimensional vibration of the organ of Corti; and otoacoustic emissions. This book will be invaluable to researchers and students in auditory science.

There has been substantial progress in understanding the contributions of the auditory forebrain to hearing, sound localization, communication, emotive behavior, and cognition. The Auditory Cortex covers the latest knowledge about the auditory forebrain, including the auditory cortex as well as the medial geniculate body in the thalamus. This book will cover all important aspects of the auditory forebrain organization and function, integrating the auditory thalamus and cortex into a smooth, coherent whole. Volume One covers basic auditory neuroscience. It complements The Auditory Cortex, Volume 2: Integrative Neuroscience, which takes a more applied/clinical perspective.

This book documents the human story behind that development. It delves into the commercial planning and implementation that led to the products success in an international, highly competitive market, and the human drama that was experienced in achieving it.