Whoosh!
Actually, the sound is quite a bit more violent; sort of like a sonic boom! It does sound pretty cool, though. I like to think that it adds to the epicness of the whole experience.
I do feel quite lucky in my being able to experience the Fountains of the Bellagio hotel. To me, they were one of the things that were a must-see attraction of Las Vegas as a whole. I got even more lucky with the fact that I visited during the holidays and they were running their Christmas show!
Even with the mob of people that were standing around, it was such a magical experience. It was even better than I'd imagined it would be to be honest. The geysers of water firing up high into the air and the loud and joyful Christmas tunes playing in the background... It was pretty great.
5/5, without a doubt. The fountains are something that I would definitely make sure to see again if I ever come back to Vegas!