It's not exactly painful (at least not to me), but it can be incredibly taxing in that the voices can break up your thought process.
I hear voices much of the time, and it is a pain in the *****, I have trouble maintaining my focus, but I feel lucky that I recognize them fairly quickly.

I'm at about 85% when it comes to recognizing the voices as hallucinations, The more people in the room, the less likely that I'll be able to identify a voice as a hallucination. Most of the time the voice are destructive, encouraging me , to act out, harm or kill myself. Most of the time I'm ok, I've accepted the voices and can filter them out of my daily life, I do have to process each voice to decide it's reality. It only takes a second to do (for me), it's become almost automatic with me.

However, if I'm in a low spot, the voices can be dangerous, I've had a long history of self injury.

I ask this with all due respect, are you asking out of curiosity as someone who doesn't hear voices?
Or are you hearing voices and merely seeking to compare notes?
I'm just wondering, either way it's okay.