An old school friend has delightedly put this as her status. That her husband had the whistle ready and BLAST = call centre caller with tinitus, lol ??
How is that funny!?
My DH had someone scream into his ear, as a teenager, and has tinitus to this day. That's over 20yrs later!
I wrote a reply giving this story but omitting that it was my DH and was told to , calm down. She has been putting up with the abuse of the constant call for months etc. And that she had suffered it herself, after a rock concert.
hmm not quite the same, I think, as having a high pitch put straight into your ear that could abuse Long Term damage.
But it would seem I am a kill joy 
DH says leave it, but I can't help feeling very angry on his behalf. Not to mention the poor soul, though I don't deny the calls are annoying, no one deserves abuse like that when it could cause lasting problems.