Whales plug their ears to block ocean noise!
What? About 250,000 sea mammals each year suffer from hearing loss and even deafness just from the loud booms emitted by the Navy’s underwater listening devices.
Do whales “plug their ears” to block ocean noise? Sonars, boat motors, underwater oil and gas drilling, and other human activities cause all kinds of loud noise. Here the actual audio from a navy sonar:
Scientists recently discovered that whales have developed a protection system to avoid hearing loss equivalent to plugging our ears when a jet flies over; a kind of volume control. Whales and other sea mammals use their sensitive hearing to navigate the waters, to care for themselves and their young, to keep track of other sea dwellers, and to find a mate. This process is called echolocation and is disturbed by noise pollution.
Learn how researchers distinguish orca sounds from other noises such as boats, ships, and other sea animals with hydrophones:
The way whales operate their volume control remains unknown. However, scientists study how whales and dolphins hear to develop an auditory warning signal that will help whales and other sea mammals clear out of a particular area before a supernoisy event takes place. In their study, they used a kind of Pavlov’s dog experiment. Researchers played a soft, mild warning tone followed by a harsh, loud tone. At a neurological point of view, it seems that after a while, the whale learned and knew that after the soft signal tone, a loud boom would follow. Consequently it desensibilized its hearing.
Here a researcher presenting his idea about attenating underwater sound with air bubbles:
All in all, the best protection remains the reduction of undersea noise.