Two‐dimensional cochlear fluid model: New results

Many theories have been developed in past years which have attempted to model the function of the human cochlea. With the recent availability of the physical measurements of Rhode [J. Acoust. Soc. Am. 49, 1218 (1971)], these theories now appear to be inadequate. In this paper, improved numerical solutions have been found for the two‐dimensional cochlear model proposed by Lesser and Berkley [J. Fluid Mech. 51,497 (1970)], using the Green’s‐function method as first suggested by Cox and Lien [(1973) unpublished]. The Green’s‐function method is used to derive an integral equation which may then be solved numerically. This procedure has proven to be stable, accurate, and faster than several other numerical solution techniques that have been tried. With an appropriate selection of the assumed membrane dissipation, the results are seen to agree within a few decibels of the Mössbauer measurements of Rhode, including the sharp change in slope observed in his amplitude ratio measurements just above the best frequency. This plateau occurs at a level which is 58 dB lower in amplitude than the amplitude at the best frequency.