Bendistraw

Blue whales are the largest animals on the planet. They are mammals so they're not to be confused with the largest fish (whale shark). Anyway, scientists have confirmed that their songs have gotten deeper. Their voices have dropped by more than half an octave since the 1960. 

No one knows why. But one conjecture is that more baritone whales indicate healthier populations: The whales may be less shrill because they're less scarce and don't have to pipe up to be heard by neighbors.

I respectfully disagree with this reasoning. While there are more blue whales, lower tones travel further. The wavelength of the lowest tone humans can hear is 16 feet long. You know how you can hear your neighbors music but only the bass and not the high pitch parts? Yeah, thats why. Thats also why 900 Mhz cordless phones worked better than the newer 1.2 Ghz cordless phones (which sold better because people think higher numbers are better and that Ghz are better than Mhz in every application).

So yeah, whales. Their songs were only slightly audible to humans because they are so low. These findings were gathered through research conducted on Navy subs fitted with software that would filter out the generic ocean noises. Other possible explanations such as a change in temperature or Ph have been ruled out.

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