A new report by top boffins says it's nonsense to suggest you can "laugh like a drain."
Sociologists and anthropologists from the University of Maidenhead have carried out a five-year study that took them around the world. In their report, published this week in Really Serious Science, they categorically deny that drains laugh.
The report ends: "Drains are complete miserable gits. They do not laugh."
Project chief, Dr Monica Parallel, said: "This has been an exhausting piece of research. I want to congratulate the team on completing the work, which at times has been harrowing, distressing - they had to endure some really bad jokes - and smelly, but not without its high points.
"Our team has been around the world listening for the laughter of drains snd I have to say we have heard none.
"We tried everything. For instance, in Britain we played complete recordings of Monty Python's Flying Circus, The Goons, Kenneth Williams saying 'Oooh, Matron!' and so on. Nothing.
"Even live stand-up by Frankie Boyle failed, but we realised that was not going to work anyway, so we swapped him for Bill Bailey and even Eddie Izzard... nothing.
"Then it occurred to us that toilet humour was bound to work, so we played the likes of Chubby Brown. To no avail."
As the teams travelled the world's drains they used 'geographically appropriate' humour but still failed to register any laughs.
"It got to the stage we even tried to tickle sewers and run-off pipes," said Dr Parallel, "but even when engineers suggested the places most likely to be sensitive to a tickle - like a junction or S-bend - we registered no response.
"Our only conclusion is that drains don't laugh, ergo, it is impossible to laugh like a drain."