reflects voice back

“Wow! Ya really have a meek face when you’re sleeping, don’cha, says Misaka as Misaka
tries out a fake Kyoto accent. Yes! You’ve got that mean old look on your face the rest of
the time. Your sleepy face is totally different, and that’s okay! says Misaka as Misa—”
“...”
Accelerator, on the other hand, his face looking none too pretty, was completely reflecting
Last Order’s entire voice.
“—ike, smiling and stuff whoaah!? Misaka’s voice got really loud!?!”
Last Order nearly toppled over. Her own voice struck her like a megaphone right next to
her ear. She shook her tiny head back and forth, but then, without hesitation, addressed
Accelerator again.

- Toaru Majutsu no Index Volume 5, Chapter 1 Part 4