reflects sound

He could reflect things unconsciously and doing this only required some simple
measurements. First, he would calculate the minimum amount of force that he needed
(gravity, pressure, radiation, oxygen, heat, voices), then he would formulate an equation
that would let him reflect all other forces aside from that. If he did actually reflect
everything, gravity would lose its grip on him and he’d soar out of the atmosphere.

Accelerator again added a reflection setting for the sounds descending upon him, then
crossed through the alley and exited onto the street. He walked along, looking up at the
sky for no reason in particular. He wasn’t looking ahead of himself, but then, he really
didn’t need to pay attention to obstacles anyway.
His reflection kept his body impervious to pain.
But that’s why he had realized it so late.
Somebody had gotten right up behind him and was moving their throat hoarsely,
desperately trying to shout something.

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