Jack had no idea what their function was, but they made a loud humming noise.

It made a small humming noise and suddenly the images of two beings appeared.

There was a humming noise in his head from lack of sleep.

He could hardly hear the machine's voice over the humming noise it was making.

The humming noise you hear is because each scope has its own motor.

It made a humming noise, but nothing more happened.

He started at the woman and made a humming noise in the back of his throat.

And you could hear a humming noise from deep inside.

He made a humming noise and started to roll his head.

The wind blew past him, making humming noises in his ears.