title: Auditory sensitivity to local stimulation of the head surface in a beluga whale (Delphinapterus leucas).
abstract: Using the auditory evoked response technique, sensitivity to local acoustic stimulation of the ventro-lateral head surface was investigated in a beluga whale (Delphinapterus leucas). The stimuli were tone pip trains of carrier frequencies ranging from 16 to 128 kHz with a pip rate of 1 kHz. For higher frequencies (90-128 kHz), the low-threshold point was located next to the medial side of the middle portion of the lower jaw. For middle (32-64 kHz) and lower (16-22.5 kHz) frequencies, the low-threshold point was located at the lateral side of the middle portion of the lower jaw. For lower frequencies, there was an additional low-threshold point next to the bulla-meatus complex. Based on these data, several frequency-specific paths of sound conduction to the auditory bulla are suggested: (i) through an area on the lateral surface of the lower jaw and further through the intra-jaw fat-body channel (for a wide frequency range); (ii) through an area on the ventro-lateral head surface and further through the medial opening of the lower jaw and intra-jaw fat-body channel (for a high-frequency range); and (iii) through an area on the lateral (near meatus) head surface and further through the lateral fat-body channel (for a low-frequency range).
authors: Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: Vladimir V
authors: VV
authors: Popov
authors: Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: Evgeniya V
authors: EV
authors: Sysueva
authors: Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: Dmitry I
authors: DI
authors: Nechaev
authors: Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: Alena A
authors: AA
authors: Lemazina
authors: Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: Alexander Ya
authors: AY
authors: Supin
mesh_terms: D000158:Acoustic Impedance Tests / Q000662:veterinary; D000161:Acoustic Stimulation / Q000662:veterinary; D000818:Animals; D001309:Auditory Threshold; D050643:Beluga Whale / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006257:Head; D013016:Sound