What's That Noise???

I'm enlisting your help. There is a website online called www.MySecretSound.com When you go there you can listen to a short little sound clip. If you can guess what the sound is then the sponsors will award you $2000.00. Our family has been trying to guess this sound since November. We thought we had it figured out but we were wrong. You only get one guess per day. If you don't want to guess for yourself but might have a clue as to what it may be, PLEASE share. If you get it right and we win, we will share too!! i can send you a list of what we have already guessed if you would like. Happy Listening!