Submarines have been using low and mid-frequency active sonar technology, a deafening soundwave that is dangerous even 300 miles from it's source. Some mid-frequency sonar systems can put out over 235 decibals, which is about as loud as a rocket launch.
Animals for hundreds of miles literally jump out of the ocean to try to avoid the sound. The damaging effects vary, bet are akin to decompression sickness causing internal bleeding and bursting organs including lungs and eardrums. When beached dolphins are reported this sonar technology is rarely mentioned in the news, although the link has been demonstrated.
"Mudpuppies, also called waterdogs, are one of only a few salamanders that make noise. They get their name from the somewhat embellished notion that their squeaky vocalizations sound like a dog's bark."- national geographic
Helium makes your voice sound high and squeaky because sound travels faster through helium than through air, which changes the resonance of your vocal tract.