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J Comp Physiol A (2014) 200:863870 DOI 10.1007/s00359-014-0929-8
ORIGINAL PAPER
Audiogram of the chicken (Gallus gallus domesticus) from 2 Hz to 9 kHz
Evan M. Hill Gimseong Koay Rickye S. Heffner
Henry E. Heffner
Received: 1 April 2014 / Revised: 7 July 2014 / Accepted: 8 July 2014 / Published online: 5 August 2014 Springer-Verlag Berlin Heidelberg 2014
Abstract The pure-tone thresholds of four domestic female chickens were determined from 2 Hz to 9 kHz using the method of conditioned suppression/avoidance. At a level of 60 dB sound pressure level (re 20 lN/m2), their hearing range extends from 9.1 Hz to 7.2 kHz, with a best sensitivity of 2.6 dB at 2 kHz. Chickens have better sensitivity than humans for frequencies below 64 Hz; indeed, their sensitivity to infrasound exceeds that of the homing pigeon. However, when threshold testing moved to the lower frequencies, the animals required additional training before their nal thresholds were obtained, suggesting that they may perceive frequencies below 64 Hz differently than higher frequencies.
Keywords Chicken Audiogram Infrasound Basilar
papilla Pigeon
Introduction
Although audiograms for over 40 species of birds have been published, almost all of them have conned their testing to the animals mid- and high-frequency hearing range with the result that little is known about the ability of birds to hear low-frequency sounds (cf. Dooling 2002). The one exception is the homing pigeon which was shown many years ago to hear lower frequency sounds than humans, i.e., they can hear infrasound
(Kreithen and Quine 1979). However, the acoustical conditions in which the pigeon audiogram was obtained differed from those of other audiograms, making direct comparisons difcult. Specically, the pigeons were tested in a small airtight pressure chamber originally designed to test altimeters, whereas the audiograms of mammals, as well as those of other birds, have been obtained in free-eld acoustic conditions. Because the pressure chamber was small (30 9 44.5 9 30 cm), it was not possible to use it to determine the low-frequency hearing ability of humans for comparison and thresholds were not attempted on another small animal. Thus, although it was undeniable that pigeons were sensitive to low frequencies, there was some question as to exactly how they would compare with other animals when tested in...