Measures of Auditory Function in Stranded Marine Mammals
Abstract
Computerized tomography (CT and MRI scanning) are powerful tools for imaging inner ear anatomy and pathology in vivo. In humans these imaging techniques are often combined with behavioral and direct physiologic measures of hearing in order to determine hearing status and cause of any loss. Behavioral measures, which consist of simple yes-no replies to a sound stimulus, are possible in trained marine mammals but are not applicable to the large number and diverse species of wild animals that strand and are rehabilitated annually. Physiologic measures, particularly auditory brainstem responses (ABR) and otoacoustic emissions (OAEs), are feasible also for marine mammals. OAE's arise from spontaneous inner ear hair cell and auditory nerve activity and are a well-documented phenomenon in land mammals. In combination with auditory brainstem response (ABR) measures, OAEs can help differentiate central, sensorineural, and conductive losses and both are now common methods for determining ear health in human infants and physically or mentally impaired adults. Human clinical techniques developed in the last five years have significantly reduced test times and enhanced waveform resolutions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 21, 2000
- Accession Number
- ADA382427
Entities
People
- Darlene R. Ketten
Organizations
- Woods Hole Oceanographic Institution