They kept their eyes fixed on the little box which gave off a faint humming sound.

She made that little humming sound again, rising on her toes to press against him.

At the stairway, both men noted a humming sound from the front of the second floor.

Precisely at this moment there was a humming sound in the room.

A humming sound began, coming from the wall by his bed.

It was warm, and he could hear a humming sound that seemed to be coming from inside.

"Find out where that strange humming sound is coming from and put a stop to it."

The water boat sent a humming sound up into the sky.

He pressed a switch, and there was a humming sound.

There was a humming sound, and the vehicle's top raised slightly.