Joe - the "finger in ear" is a way of hearing yourself when singing. If there is a lot of ambient noise around putting your finger in your ear (well, actually just pressing the bottom flap of your ear up against the hole leading to the eardrum) helps you to hear your own voice against the noise, by filtering out certain frequencies (probably the higher ones). You also get more immediate feedback on what's going out of your mouth, so can keep in better tune, if, like me, you're essentially tone deaf. I find that it also works when listening to an amplified band where the singing is drowned out by the high frequency noise of cymbals, elctric guitars, etc.

So, if your audience are sticking their fingers in their ears, take it as a compliment - they actually are trying to hear you better!

In Britain, anyway, "finger in ear" is almost synonymous with folk singer, and is a frequent source of jokes, none of which I can remember.

Cheers

Rick.