The two humans heard its noise and looked up.

At the higher levels, humans in the prime of life can hear noises up to about 20,000 cycles per second.

The humans, standing by a patch of freshly turned earth, heard.

Most humans would hear nothing till they got much closer.

But there were other sounds which humans couldn't hear.

The humans couldn't hear what he had said either time.

The sounds bats make use frequencies that humans cannot hear.

"Why you humans can't hear a guy making a racket coming through the brush, I'll never know."

The few humans around to witness, had they even noticed her dance, would not be hearing the sounds she created for him.

Once we have this information, we should be able to tell if humans can really hear in space.