Thanks for all the helpful suggestions, and the fascinating history of cupping the ear. No finger IN the ear - got it!

I'm not concerned about staying on pitch, it's more that when I can't hear myself sing I can't tell whether I'm getting the vocal quality I want. But given that a dead room with moderate background noise is far from ideal singing conditions, maybe I shouldn't be worrying about optimum vocal performance.

What I mean by "house party" is a party where the host has asked me to sing for his guests in his living room for about 30 minutes. For example, at the beginning of February I was asked to sing at a "Brigid's Day" party (I did "The Snows They Melt the Soonest" because it seemed very appropriate). Most people at the party stop talking to listen, and I try to do songs where the other guests can sing along on the chorus (like "Johnny Jump-Up"). SO the music is not the main reason for the party, but it's not background either.

As some have suggested, practice is the probably the best way to learn how to get the right vocal quality whether I can hear myself or not. But I will try the ear cupping thing to see how I like it!