The noise really bothered me on our old model, but it broke recently and we replaced it with a different brand. I cannot believe how quiet the new one is. I think it's less powerful but it's worth it just for the noise. It's not just the suction that's quieter either, it also runs into walls/obstacles much less aggressively.

Might be something to look into when/if you decide to replace yours! There's probably a model out there that won't bug your wife as much.