Spontaneous otoacoustic emissions from free-standing stereovillar bundles of ten species of lizard with small papillae

Spontaneous otoacoustic emissions (SOAE) were measured in 10 lizard species from the families Iguanidae, Agamidae and Anguidae. The typical feature of these papillae is that the hair cells in the higher-frequency papillar regions that produce SOAE are not covered by a tectorial structure. The number of hair cells in the species used here was between 58 and 292 per ear. SOAE could be measured from all species, but some of their characteristics varied with papillar anatomy. Thus very small papillae produced fewer and smaller SOAE than larger papillae.