That was when she heard the key turn in the lock.

Once outside, he heard a key turn in the lock of the door behind him.

It was perhaps an hour later when she heard a key turn in the lock.

I heard the sound of a key in the lock.

They came down into the hall and heard a key in the lock.

They heard the sound of the key in the lock.

After a long time he heard the key in the lock.

I heard the key turn in the lock, and saw the doctor at the open door.

The three men heard the key turn in the lock from outside.

She heard the key turn in the lock and saw the door open.