An Introduction to Testing the Hearing of Marine Mammals

For several years of my Ph.D. studies, I was part of research into marine mammal hearing and biosonar. My introduction to these was pretty much the “immersion” sort of experience: I spent two and a half months on San Clemente Island assisting in data collection and analysis for a study on the hearing of white whales at depths down to 300 meters.

Diane and I also provided programming for data collection and analysis and assistance in experimental design for tests of hearing and temporary threshold shift in bottlenose dolphins and white whales.

In 2001, Diane and I were able to visit the Point Defiance Zoo and Aquarium, where hearing tests of the sort we had contributed to were being conducted. I was able to take some decent photos of the proceedings. We put together a web page and got permission from the kind folks at Point Defiance to release it to the public. (Photographs taken at facilities like Point Defiance are usually not publicly publishable without obtaining a site release or specific permission.) On the page, we explain the basics of performing behavioral audiograms on marine mammals, show a graph of audiogram data for white whales and bottlenose dolphins, and provide a short bibliography of technical literature on behavioral audiograms and hearing tests for these species.