Dominic Behan said the reason he put his finger in one ear was because he didn't like half the songs he was singing.

But it does help you hear yourself, especially in a noisy environment - more so if you stick the thumb behind the ear and press it to close down the earhole. It means, I suppose, that you get the sound coming round inside the head instead of taking the route round the outside.

Meself, I think it's an affectation not to do it, rather than the other way round. I'd rarely consciously choose to do it, but at times I've consciously chosen not to, what with the FIE jokes.

If you're playing an instrument of course you have to do without the technique - but then you've got the instrument to help you keep in tune.

And then of course some of us are getting a bit hard of hearing these days, and that's always been a reason for the hand cupped to the ear, for traditional singers and all.