title: Auditory brainstem responses of Japanese house bats (Pipistrellus abramus) after exposure to broadband ultrasonic noise.
abstract: Echolocating bats forage and navigate within an intense soundscape containing their own sonar sounds as well as sounds from other bats. To determine how the bat's auditory system copes with these high noise levels, auditory brainstem responses (ABR) were measured in the Japanese house bat, Pipistrellus abramus, before and after exposure to ultrasonic noise (30 min duration). Noise spectral content (10-80 kHz) and level (90 dB sound pressure level) are within the ranges these bats experience in their natural environment. ABR thresholds to test frequencies of 20, 40, and 80 kHz did not vary significantly between pre-exposure and post-exposure times of 0 and 30 min. Amplitudes and latencies of the P3 wave at suprathreshold were not significantly affected by noise exposure. These data show that the bat's hearing is not compromised when exposed to background sounds similar in wideband frequency content and sound level to what the animal encounters naturally. These results provide a baseline for examining how the bat's auditory system deals with other intense sounds, such as those emitted by anthropogenic sources or those producing temporary threshold shifts in other mammals.
authors.affiliation: Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, Rhode Island 02912, USA.
authors.forename: Andrea Megela
authors.initials: AM
authors.lastname: Simmons
authors.affiliation: Neurosensing and Bionavigation Research Center, Faculty of Life and Medical Sciences, Doshisha University, Kyotonabe 610-0321, Japan.
authors.forename: Shokei
authors.initials: S
authors.lastname: Boku
authors.affiliation: Neurosensing and Bionavigation Research Center, Faculty of Life and Medical Sciences, Doshisha University, Kyotonabe 610-0321, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Riquimaroux
authors.affiliation: Department of Neuroscience, Brown University, Providence, Rhode Island 02912, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Simmons
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001309:Auditory Threshold; D002685:Chiroptera / Q000502:physiology*; D004455:Echolocation; D004777:Environment; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D008144:Loudness Perception; D008297:Male; D009622:Noise / Q000009:adverse effects; D011930:Reaction Time; D013018:Sound Spectrography; D014465:Ultrasonics