Click and low-, middle-, and high-frequency toneburst stimulation of the canine cochlea.
A method was developed to deliver tonebursts ranging in frequency from 1 to 32 kHz for frequency-specific assessment of the canine cochlea. Brainstem auditory-evoked responses (early latency responses, 0-10 ms) to a click (CS) and to 1-, 2-, 4-, 8-, 12-, 16-, 24-, and 32-kHz toneburst stimulations (TS) were compared at 80-dB sound pressure level stimulus (SPL) intensity in 10 adult dogs. All stimulations yielded a 5-7 positive wave pattern, with the exception of the 1-kHz TS, which evoked a frequency-following response (FFR). Thresholds were lowest for the CS and the 12- and 16-kHz TS. All individual peak latencies for TS were significantly (P < or = .05) longer than for CS. Peak I latencies were significantly (P < or = .05) shorter for the 12- and 16-kHz TS than for the other TS. Interpeak latencies I-V were significantly (P < or = .05) longer for the 4- to 32-kHz TS than for CS. Differences in interpeak latencies I-III were not significant. Amplitudes of waves I and V were significantly (P < or = .05) lower for TS than for CS, except for higher wave V amplitude (P < or = .05) at 2- and 32-kHz TS. Peak I-V amplitude ratios were significantly (P < or = .05) higher for the 2-, 4-, 16-, 24-, and 32-kHz TS and lower for the 8- and 12-kHz TS, compared to CS. We conclude that reproducible information on frequency specificity of the canine cochlea can be obtained by TS. This report provides a normative database for parameters needed to evaluate frequency-specific hearing loss in dogs.
Ter Haar
G
G
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, The Netherlands. G.TerHarr@vet.uu.nl
Venker-van Haagen
A J
AJ
de Groot
H N M
HN
van den Brom
W E
WE
D000162:Acoustics; D000818:Animals; D001300:Audiometry, Evoked Response / Q000379:methods / Q000662:veterinary*; D001933:Brain Stem / Q000502:physiology; D003051:Cochlea / Q000502:physiology*; D004285:Dogs / Q000502:physiology*; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis / Q000662:veterinary*; D008297:Male; D011930:Reaction Time; D012016:Reference Values