The only airline I know for certain that does it is Omni (euro controller here), and that's only because the guy apologised to me for possible poor transmission quality (there was zero difference in his case).He obviously didn't realise I talk to Aeroflot and Turkish on a daily basis.
Apart from the above omni though I must say it's been very hard to understand what you folks are actually saying when you're on the oxy. Definitely worth bearing in mind if you're ever on it.