By the exhausted mechanical sound of it he has been sobbing for a long time.

Mike stopped by it and leaned in when he heard faint mechanical sounds.

So quiet it was that any mechanical sound would surely have reached him.

It was that same distorted, mechanical sound as the last call.

A minute; then came the dull, mechanical sound of the elevator.

He heard a slight mechanical sound as the figure walked forward.

When they stopped at the bottom of the shaft, the mechanical sounds ceased.

His music was very noisy and full of mechanical sounds.

But the wind was blowing in their direction, and they heard a faint mechanical sound.

With the microphone aimed directly, the mechanical sound was clear.