Expanded hearing range

I felt bones crack underneath me, and I formed eyes close to the skull just as I pulled the skull open. The light coming through my body distorted things a little, but I could see well enough.

There it was.

He wasn’t human, not quite. There were some mutations there; he could hear sounds at an expanded range. He’d be able to hear infrasound easily enough too. Would that be enough for him to directly sense thinnies? If there was a whole species like him, would they have spread out to other worlds as well as filling their own? Or maybe he was a Tinkertech creation. I didn’t see any obvious signs of modification, but that didn’t necessarily mean anything.

***

Reacting