It is hard to take a claim seriously when the same person also claims sperm whales can hear each other over 1000+ miles which is just not true, sperm whales max out at like 40 miles.

I tried to find where this claim first comes from with no luck.

It does seem to be based on the fact that a sperm whale click can be well above 200dB and that 185+dB is considered dangerous to humans. The problem seems to be though that whoever made the original claim didn't know that dB in water and dB in air are not the same. In air a sperm whales clicks would be in the 170's, still going to burst your eardrums but probably isn't going to kill you.