First thing, don’t use White Noise, use Pink Noise. It’s much more relaxing and better at masking real world noises.
Second, unless you have a CD player that can play MP3 discs, you won’t be able to put 9 hours of audio onto a CD. You will always be limited to 80 minutes.
The problem is not with Audacity’s output format, it’s with the CD-audio standard. You will need a special CD player to play any non-standard format.
<<<What I want is 9 hours straight, but a MP3 format will not allow anything close to that
to be recorded on a CD.>>>
Oh, yes it will. The problem, as pointed out, is that then you won’t have a standard Music CD. If you want to put an MP3 music file onto a Data CD, you can get hours and hours of show on there. The problem will be playing it back. You need a computer or CD player that knows that MP3 is. I think my latest car player knows how to do that.
There is another way. You can use television technology. Instead of a CD player, use a DVD player, then just don’t hook up the monitor. Unlike CDs, DVDs change size depending on the show. You can use AC3 compression (5.1 surround sound) and only use the first two channels. That’s where you put your pink noise track. The picture can be one long black frame. You should be able to get 8 hours of “show” onto one standard television DVD by doing that.
And yes, don’t use white noise. That sounds like an arc welder blasting through steel girders. Pink (or even brown) noise is much more relaxing. I have personally with these hands pumped pink noise into my headphones so I could pay attention to my editing in a noisy room.
Given where I live, one might wonder why I don’t take the equipment out and record real surf. Why indeed.