That's a funny tickle. What is that, trying to worm its way into his thoughts? It's noticeable enough for him to stop and whip his head from side to side. He can't actually hear anything, though; he can only feel that something's scratching at his thoughts.

He doesn't like it.

"Stop!" He starts swatting his hands around his head, beating at the air like the pressure is a fly he can knock away.