Title: A comparative study ofevoked otoacoustic emissions in geckos and humans
Abstract:
Otoacoustic emissions in mammalian ears have been classified based on their presumed mechanisms of generation into reflection- and distortion-source subtypes. Models of these mechanisms often make explicit reference to waves traveling along the cochlear partition. For example, the coherent-reflection model explains the properties of mammalian reflection-source OAEs by showing how they emerge from the coherent ``backscattering'' of forward-traveling waves by impedance perturbations in the mechanics of the cochlear partition. Since the lizard basilar papilla manifests no obvious analog of the mammalian traveling wave, detailed characterization of lizard OAEs offers an important opportunity to test and extend our knowledge of emission mechanisms. We report otoacoustic measurements (DPOAEs, SFOAEs, and SOAEs) in the ears of healthy adult leopard geckos (eublepharis macularius). We compare and contrast the properties of gecko and mammalian OAEs and discuss their implications for mechanisms of OAE generation.