As they ran, the sound under their feet grew louder.

The sound grew, and the girl recognized it before he did.

He ran after it as the sound of the other car grew louder behind him.

The sound of running water grew louder as he went down.

Until there was a different sound, and this from behind, growing louder by the moment.

The sounds of movement grew still louder, as if they were in the room.

The sound of the running battle outside the conference room was growing louder still.

The sound grew until he could hear it above the beat of the engine.

The sound of water faded away to nothing or grew again, by turns.

But the sounds of death in the street were growing louder.