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Hearing, vocalization and the external ear of a marsupial, the Northern Quoll, Dasyurus hallucatus
Author(s) -
Aitkin L. M.,
Nelson J. E.,
Shepherd R. K.
Publication year - 1994
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903490305
Subject(s) - audiogram , marsupial , biology , nocturnal , prey detection , bioacoustics , audiology , auditory brainstem response , acoustics , zoology , ecology , hearing loss , predation , physics , medicine
As part of a continuing study of the development of the marsupial auditory system, auditory brainstem responses (ABR) were recorded and an ABR audiogram was constructed for five female Northern Quolls ( Dasyurus hallucatus ), which are nocturnal carnivores. The best frequency for hearing lies between 8 and 10 kHz, and at 50 dB SPL there is a range from about 0.5 to 40 kHz. Vocalizations of adult quolls and pouch‐young were recorded with a digital audio tape recorder, and the power spectra of representative calls were compared with the ABR audiogram. The common adult vocalization have most energy at the lower end of the hearing range, whereas frequencies that are dominant in the isolation calls of the pouch‐young lie close to the best frequency of hearing. Samples of nocturnal sounds of the habitat of the quoll were also recorded and analyzed. Power spectra have peak energy at frequencies between 2 and 5 kHz, with a smaller contribution above 10 kHz. The spectrum contains relatively little power at the best frequency of hearing. Measurements of the sound pressure level at the external ear canal as a function of stimulus frequency and location in space suggest that the directional amplifying properties of the pinna will operate most effectively on sound frequencies at the upper end of the quoll's hearing range, a region that may be important in prey detection. Comparisons are made with other mammalian nocturnal carnivores and with other marsupials. We speculate that, for nocturnal carnivores, one role of the low‐frequency part of the hearing range concerns the recognition of adult conspecifics, the mid‐frequency range is important for the detection of pouch‐young, and the upper range may be particularly concerned with prey/predator detect on. © 1994 Wiley‐Liss, Inc.