title: Audiogram of the big brown bat (Eptesicus fuscus).
abstract: The audiograms of three big brown bats (Eptesicus fuscus) were determined using a conditioned avoidance procedure. The average audiogram ranged from 0.850 kHz at 106 dB to 120 kHz at 83 dB SPL, with a best threshold of 7 dB at 20 kHz and a distinct decrease in sensitivity at 45 kHz. The results confirm those of a previous study by Dalland (1965a) that the big brown bat has good high-frequency hearing coupled with poor low-frequency hearing. Comparative analysis suggests that the bat's good high-frequency hearing initially evolved for passive sound localization and that it was later coopted for use in echolocation. In addition, the restricted low-frequency hearing of the big brown bat is typical of mammals with good high-frequency hearing.
authors.affiliation: Department of Psychology, University of Toledo, OH 43606, USA. fac2622@uoft01.utoledo.edu
authors.forename: G
authors.initials: G
authors.lastname: Koay
authors.forename: H E
authors.initials: HE
authors.lastname: Heffner
authors.forename: R S
authors.initials: RS
authors.lastname: Heffner
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001299:Audiometry; D001309:Auditory Threshold / Q000502:physiology*; D002685:Chiroptera / Q000502:physiology*; D003213:Conditioning, Psychological; D004195:Disease Models, Animal; D006319:Hearing Loss, Sensorineural / Q000209:etiology; D008297:Male; D013017:Sound Localization