EVERY parent must have experienced it.

The children are fast asleep in bed when you suddenly feel the urge to answer a call of nature.

Now you are faced with a dilemma - do you pull the flush and risk waking them up, or leave it until morning?

It is not the most pleasant subject to pontificate on but one that Derek Muir has spent the last year deeply analysing.

Now the 23-year-old graduate, from Cronton, near Widnes, has won an international award for his pioneering invention, the Stingray - a toilet seat that muffles the sound of the flush.

"A lot of people design things not everyone has contact with," said Mr Muir last night. "But with my toilet seat, a lot of people seemed to be aware of the problem of flushing the toilet late at night.

"I'm more of a practical, functional designer, and I would rather create things that solved problems, rather than things that just look nice."

Mr Muir was commissioned by Huddersfield University, from where he has just achieved a first class honours degree in product design, to invent a product made from two plastics made by material science firm, Bayer.

He said: "One of the plastics is a kind of foam with a thick outer skin. I knew a lot of people with children or light sleepers in the house had this problem of not wanting to flush the toilet at night, which is not very hygienic.

"So I was able to use this plastic to make the seat. It works by forming a seal between the lid and the seat, and the seat and the rim.

"The harsh noise is caused by the flushed water hitting the water in the bowl. So, when the lid is down, the seat stops that sound escaping through the gaps.

"As well as being warmer and more comfortable to sit on, it is also more hygienic, because germs can escape through the gaps when the toilet is flushed. This way, germs can't escape."

The Stingray, which blocks out 40% of noise, went on to win the Student Plastics Design Award, organised by the Institute of Materials, Minerals and Mining. As a result, Mr Muir received £1,000 and a placement with Bayer in Leverkusen, Germany.

The next step is to move to London, where he has had interest from manufacturers such as Dyson and Black and Decker, to join his fiancee, Catherine Niccol, an interior designer. And while he is unsure how much money he will make from the design, Mr Muir says he believes it could reap serious rewards.

"The market is huge for something like this. Everyone has a toilet seat in their house. In fact, most people have two.

"People have also said it would be ideal for hotels with thin walls and for new apartment blocks that are going up all over the place.

"However, the toilet seat design was only my minor project at university - I have also designed a safer stepladder, which is triangular and acts like a skew-whiff tripod.

"The university is setting up a company to lease the design to manufacturers."

But whatever Mr Muir invents from now on, it will probably be his lavatorial creation that people will remember most.

"It would be pretty weird being famous for designing a toilet seat," he said. "But I don't mind, because it really is something everyone can relate to."