Question on earplugs
Consider also Musicians earplugs. Regular earplugs affect frequencies heard, even though covering one ear shouldn’t affect as much, because the mind compensates.
Both Musicians and regular earplugs cause an occulsion (sp?) effect, which will make you think you’re bassier. You’ll need custom made earplugs for singers (about $200 and a skillful audiologist).
One unusual way of solving this, is to adjust for the DJ, by possibly pulling out custom made earplugs, if he doesn’t play so that you can hear your voice.
Lastly, hearing your voice is a trained skill. If you practice a bit, you’ll hear your voice despite the loud music.