Do extant elephants have superior canal dehiscence syndrome?
CONCLUSIONS
X-ray CT of an Asian elephant's skull suggest that elephants do not have a labyrinthine 3(rd) mobile window. This excludes the concept that elephants benefit from enhancement of bone conducted vibration by an extra opening of the labyrinth. This finding does not, however, exclude that elephants use bone conducted hearing for seismic detection, nor that other species may use an extra labyrinthine opening for improved detection of seismic signals.


OBJECTIVE
In man, a pathologic extra opening of the bony labyrinth causes altered hearing with supranormal bone conduction. Theoretically, this variation in auditory performance could be advantageous for detection of seismic waves.


METHODS
The skull of an adult Asian elephant was examined by X-ray computed tomography to investigate whether a natural '3(rd) mobile window' mechanism for enhanced sensitivity of body sounds exist in elephants.


RESULTS
Although the entire elephant's skull was otherwise broadly aerated, the labyrinth areas were surrounded by dense bone.
a 1 Department of Audiology and Neurotology, Karolinska University Hospital , Stockholm, Sweden.
Krister
K
Brantberg
b 2 Department of Radiology, Karolinska University Hospital , Stockholm, Sweden.
Babak
B
Falahat
c 3 Department of Zoology, Swedish Museum of Natural History , Stockholm, Sweden.
Daniela C
DC
Kalthoff
D000818:Animals; D001844:Bone Conduction / Q000502:physiology*; D004606:Elephants; D006309:Hearing / Q000502:physiology*; D006314:Hearing Loss, Conductive / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D012001:Hyperacusis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D008297:Male; D012665:Semicircular Canals / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed
CT; bone conduction; conductive hyperacusis; hearing; seismic; third mobile window