I have two white noise machines, have them in stereo, one on each side of the bed. It's useful to be able to adjust them separately, I've got tinnitus in one ear more than the other so don't need it to be as loud on that side.
As I get older, deafness will likely reduce my need to rely on technology.
This is such a great idea. I got a machine for my side of the bed, but my wife can barely hear it (which is more annoying than hearing it), and if I turn it up it's too loud for me.
Stereo - genius!