Diversity In Auditory Mechanics Proceedings Of The International Symposium

This proceedings volume contains papers presented during the meeting on Diversity in Auditory Mechanics by leading neurobiologists, biophysicists and mathematicians interested in auditory periphery.

Symposium held in 1999 near Sendai in Japan.

The articles in this volume are the results of discussions among biophysicists, neurobiologists and mathematicians with research interests in auditory mechanics and signal processing. The topics covered include: mechanics and models of hearing organs; auditory periphery and its models; middle ear; traveling wave and cochlear amplifier; emissions; outer hair cell; electromotility; central auditory processing; auditory nerve responses; and hearing in non-mammals. Contents:The Middle EarThe Cochlea (Measurement)The Cochlea (Model)The Outer Hair CellElectromotilityEmissionsAuditory Nerve ResponsesCentral Auditory ProcessingHearing in Non-Mammals Readership: Researchers and graduate students in ENT, neuroscience, biophysics and biomedical engineering. Keywords:

The workshop brought together experts in genetics, molecular and cellular biology, physiology, engineering, physics, mathematics, audiology and medicine to present current work and to review the critical issues of inner ear function. A special emphasis of the workshop was on analytical model based studies. Experimentalists and theoreticians thus shared their points of view. The topics ranged from consideration of the hearing organ as a system to the study and modeling of individual auditory cells including molecular aspects of function. Some of the topics in the book are: motor proteins in hair cells; mechanical and electrical aspects of transduction by motor proteins; function of proteins in stereocilia of hair cells; production of acoustic force by stereocilia, mechanical properties of hair cells and the organ of Corti; mechanical vibration of the organ of Corti; wave propagation in tissue and fluids of the inner ear; sound amplification in the cochlea; critical oscillations; cochlear nonlinearity, and mechanisms for the production of otoacoustic emissions. This book will be invaluable to researchers and students in auditory science.

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.

Auditory Sound Transmission provides an integrated, state-of-the-art description and quantitative analysis of sound transmission from the outer ear to the sensory cells in the cochlea of the inner ear. It describes in detail the structures and mechanisms involved and gives their input and transmission characteristics. It shows how sound transmission in one part of the ear depends on the input characteristics of the next part and how sound is analyzed in the inner ear before it reaches the nervous system. The book is divided into seven chapters. The first gives the general overview of the path of sound in the ear. The second concerns the acoustics of the outer ear which is important not only for sound transmission in the ear but also for the design and calibration of earphones, as well as for clinical and research measurements of sound pressure in the ear canal. The third chapter analyzes the middle ear function which is crucial for adapting the conditions of sound propagation in the air to those in the inner ear fluids. The middle ear is prone to various malfunctions, and it is shown how they change the acoustic conditions measured in the ear canal and can be diagnosed on this basis. The next three chapters are dedicated to the most intricate mechanical part of the auditory system, the cochlea. Because of its complexity, its function is explained in three steps: first, with the help of simplifications produced by death; second, on the basis of the measured characteristics of the live organ; third, with the help of quantitative analysis. The last chapter describes cochlear mechanisms underlying pitch and loudness perception.