Mature mammal hearing loss: a natural experiment in Presbycusis

TitleMature mammal hearing loss: a natural experiment in Presbycusis
Publication TypeConference Paper
Year of Publication2009
AuthorsKetten, D. R., S. Ridgway, J. J. Arruda, J. T. O' Malley, S. R. Cramer, and M. Dunn
Conference Name18th Conference on the Biology of Marine Mammals
Date Published10/2009
Conference LocationQuebec, Canada
Keywordshearing loss, mature mammal, presbycusis

For humans, we have extensive data on hearing loss from congenital defects, aging, noise exposures, traumatic events, and disease. By contrast, natural, non-experimentally induced hearing loss in other species, particularly presbycusis and NIHL, is not commonly studied. Concern for anthropogenic acoustic impacts in marine species became particularly acute in the last decade. While we have substantial information on the basic hearing ability of many marine mammals, we know little about the incidence and nature of natural hearing loss. This paper presents data from computerized tomography (UHRCT), histology, and electron microscopy of 38 marine mammal ears, including 15 ears from mature captive bottlenose dolphins (Tursiops truncatus) for which audiometric data were available. Specimens were collected postmortem, scanned, and mapped via light microscopy to determine the nature and sites of inner and middle ear pathologies.