The sound of running water can be soothing, but the gurgle of water rushing thru the downpipes at night can be annoying and keep you awake. Thus...The Silent Downpipe! I envisage something that could be retro-fitted to existing pipes, but there would need to be versions for round and rectangular pipes. Or a totally new downpipe that can fit to new houses. Some understanding of the rotational direction of the water would be required. Anticlockwise in the southern hemisphere and reverse...