Waves in the cochlea and in acoustic rainbow sensors

A WKB solution to the cochlear wave equation is derived, which results from interaction between passive dynamics of basilar membrane and 1D fluid coupling in scalae, including both viscosity compressibility. The effect various nondimensional parameters on form this discussed. damping parameter a phase-shift are shown have greatest influence response under normal conditions cochlea, with compressibility only playing minor role. It then that case an acoustic rainbow sensor, comprised discrete series Helmholtz resonators duct, governing continuous limit has same as equation. governed by ratio resonator volume connecting duct can be much larger than so plays more dominant role determining response.