There was a sharp rap on the other side of the bathroom wall.
She'll be sure to look around, if I give it a few good sharp raps.
There was a sharp rap on the glass by Joe's window.
After five minutes there came a sharp rap on the door.
A sharp rap on the door brought her back to the present with a start.
A sharp rap at the door made both of them jump.
Minutes of silence went by; then came a low but sharp rap at the door.
It had all started with a sharp rap at the door.
There was a sharp and hard rap on the closed door.
There were two footsteps and a sharp rap on the door.