Hearing Sensitivity in White-tailed Deer
Ken Risenhoover, Jon Hunter, Roy Jacobson, and Glenn Stout
Although white-tailed deer (Odocoileus virginianus) vocalizations have been recorded and described, virtually nothing is known about “audition” or the range of hearing by deer and other ungulates. To address this need, I conducted some controlled experiments in collaboration with Dr. Jon Hunter at the College of Veterinary Medicine at Texas A&M University. Audiograms were determined for 5 bottle-raised adult white-tailed deer (3 males, 2 females). While anesthesticized, deer brainstem evoked potentials were recorded from the frontal sinus, vertex, and dorsal border of the zygomatic arch.
Stimuli consisted of 45-ms pure-tone pips (2 ms rise and fall time) from a McNaural SM-400 amplifier connected to a Nicolet Biomedical Instruments “Pathfinder II” and were delivered using Amplivox audiocup earphones held against the deers ears. Evoked potentials were recorded at intensity levels of up to 95 dB for frequencies of 0.5, 1, 2, 4, 6, 8, 12 and 16 Khz. Estimates of thresholds of hearing sensitivity for each frequency were based on averages for 1000 recorded responses.