Led Zeppelin in Liverpool March 1971 was so loud (and I was standing at a reasonable distance) that it hurt. I left halfway that concert because of that but, although they played well, also because they were very boring.
I can't remember exactly, but several decades ago I saw Jetro Tull in "de Doelen" in Rotterdam NL and my only functioning precious ear (since birth) kept ringing for three days. Ever since I always take small cotton wool plugs along. The Stones concerts are in general fine in terms of loudness, but occasionally (like Dusseldorf 2014) in indoor stadiums I filter some noise with a plug.
Like BV says, once destroyed, there is no way back.
My neighbour, who works for an institute dealing with deafness problems, said to me on several occasions when a car was passing by with blasting (music or "bang-bang") noise coming out: "Ah, here goes another future customer". Sinical, but oh so true