I find that wearing earplugs really helps with the background noise in bars thing. Counter-intuitively (for me) it makes it much easier for me to hear the person next to me.
My favourite kind (now) are the Leight Laser Lites - got introduced to them whilst working at a place with a datacentre and was soon borrowing* several pairs every time I went down to the basement.
Cheap in bulk, which is handy because I need them to sleep.
Cheap in bulk, which is handy because I need them to sleep.