Silent computer

I know this topic has probably been discussed before, however I'll take that risk and ask again.
I was thinking about the things that I hate the most about computers and, without a doubt, noise has to be one of them. Especially since my computer is in my bedroom. Would it be possible to render a computer quiet enough as to not be noticed in a silent room? I imaging this would require the use of special fans or maybe isolating the case in sound proof material. But then cooling would be an issue...

Anyway, I would appreciate your thougts!

Thanks,

Hugh