Hearing loss in stranded dolphins

New research into the cause of dolphin "strandings" - incidents in which weakened or dead dolphins are found near shore - has shown that in some species, many stranded creatures share the same problem.
They are nearly deaf, in a world where hearing can be as valuable as sight.
That understanding - gained from a study of dolphins' brain activity - could help explain why such intelligent animals do something so seemingly dumb. Unable to use sound to find food or family members, dolphins can wind up weak and disoriented.
Researchers are unsure what is causing the hearing loss: It might be old age, birth defects or a cacophony of man-made noise in the ocean, including Navy sonar, which has been associated with some marine mammal strandings in recent years. 

Press report from the Washington Post, original research is from a PLoS ONE paper out last week:  Hearing Loss in Stranded Odontocete Dolphins and Whales
Thanks to Josh for the tip.