http://www.q-music.be/page/het_geluid
Click on "Beluister het nieuwe geluid" (center of the page)

It's a game on the radio.
Every hour you can guess what this sound is. Each time someone says the wrong answer they add 100€ (£67).
Total amount you can win is 79400€ (£53000) at the moment

And I haven't got a clue