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1 .This is Scientific American 60-Second Science. I'm Christopher Intagliata. Got a minute?
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2 .Beluga whales live in the world's cold northern seas, where they endure months of perpetual darkness.
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3 ."So they have to use sound, rather than sight, in order to find their way around."
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4 .That's Aran Mooney, a marine biologist at Woods Hole Oceanographic Institution, in Massachusetts.
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5 .He says belugas have really fast hearing, too:
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6 ."Sound underwater travels five times faster than it does in air.
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7 .And so those guys have to basically perceive and utilize sound five times faster than we do."
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8 .He and his colleagues traveled to Bristol Bay, Alaska, to test belugas' hearing in the wild.
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9 .They captured seven belugas for routine physicals.
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10 .And played them a series of frequencies, while measuring the whales' brain activity with electrodes.
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11 .Turns out the whales' hearing was sharp, and similar to that of captive belugas.
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12 .Which means they could appreciate sound ranging from about 4 kilohertz to 150, a frequency nearly eight times higher than the upper limit of our ears.
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13 .The results are in The Journal of Experimental Biology.
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14 .The older belugas tested in this survey still had decent hearing too.
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15 .But that might not be the case for belugas living in noisier Cook Inlet, near Anchorage.
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16 ."There's a lot of military activities, a lot of commercial activities in Cook Inlet, and those animals are known to be declining at a rate of about two percent per year.
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17 .And we think noise is a major stressor to those animals."
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18 .And now that researchers know what wild belugas should be able to hear,
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19 .they can test Cook Inlet belugas, to see whether that underwater noise is, literally, deafening.
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20 .Thanks for the minute, for Scientific American 60-Second Science.I'm Christopher Intagliata.
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