making every human-made underwater noise particularly disruptive for ocean dwellers. For marine mammals like whales, dolphins, sea lions and seals, sound isn't just noise—it's their primary mode ...
Solitary dolphin in Baltic Sea recorded making 10,833 sounds Vocalisation patterns suggest dolphin may be calling out for friends Experts intrigued by emotional implications of dolphin's noises ...
and its advantages makes deep-sea diving much safer. As well as those pretty important advantages, heliox does bring with it a rather amusing side effect: it makes you sound a bit like a chipmunk.