When I sing at a formal gig we bring a sound system and I can hear myself through the monitors. Recently I've sung at a couple of house parties where it's just me and a guitarist, maybe a fiddle, but no sound system. I'm having a hard figuring out how to sing well when I can't hear myself because of the acoustics of the room. I feel like I'm forcing my voice and trying to sing as loud as I can just to hear myself, and I suspect it sounds strained. I know I'm not enjoying it.

Putting a finger in one ear helps me hear myself, but it would look silly doing it in public. Maybe wearing an unobtrusive earplug in one ear would help? Any tips or sucessful approaches out there?