A re-examination of Békésy's travelling wave theory

Abstract

The mammalian cochlea has an outstanding ability to analyze frequencies. This function is explained by the travelling wave theory proposed by Békésy. However, the theory is based on the results of experiments using the cochlea lacking the normal configuration of a fresh cadaver. For example, a large hole was made in the wall of the Scala vestibuli to observe the basilar membrane directly. In addition, the organ of Corti and the tectorial membrane were removed. To resolve the issues associated with the previous experimental conditions, I developed a cochlea model using transparent resin and re-examined Békésy's travelling wave theory. When the window was closed, the basilar membrane did not vibrate, and the round window membrane vibrated in the reverse phase to the oval window membrane. When the window was open, the basilar membrane and the third window vibrated together, and the round window membrane did not vibrate at all. Based on these findings, I concluded that Békésy's travelling wave theory should be immediately reconsidered.