Toothed Whale Hearing Senstivities Can Be Turned Up and Down
Supin, Nachtigall, Breese. Hearing sensitivity during target presence and absene while a whale echolocates. J. Acoust. Soc. Am. 123 (1), January 2008, 534-541
This very interesting paper, digging deeper into a topic that had emerged in previous studies of toothed whale hearing, reveals that a pilot whale could apparently “turn up” its hearing sensitivity, so that it could listen for fainter (more distant) sounds when echolocation clicks did not reveal nearby echoes. The research used a captive whale, outfitted with suction-mounted EEG electrodes to measure evoked potentials as it echolocated; half the time, a target fish was nearby, and half the time there was no nearby fish. When no fish was present, hearing sensitivity was 20dB higher (ie it could hear sounds 20dB more faint).