It was extremely aggravating, and anxiety inducing. Yuugi would only be able to catch it from time to time as he spoke to Kaiba in the next little while, but he'd twitch his head imperceptibly to some direction when he heard something that wasn't there. Sometimes he could ignore it, but other times it was too pervasive.

Are you alright?

He mouths it suddenly. Yuugi had taken care of him for so long...but what of his current state? Had he slept? Was he going to be on his game for the next experiment that might befall them?