No sarcasm: Look into Nursery Sleep Soothers. While they sell white noise machines targeted at adults, they're all terrible because it is a niche market. But in the nursery sleep soothers category you can find a bunch of high quality white noise machines for a good price.

For example the Marpac Dohm has an actual spinning fan inside designed to generate white noise. But you can find digital noise simulators who can do: industrial sounds, water, fan noise, nature, and so on.

Is the Marpac Dohm actually targeted at nurseries? I've seen it quite frequently in medical waiting rooms. It helps provide privacy for those having sensitive conversations behind flimsy doors.

On Amazon at least they sell it under Baby Sleep Soothers and Sound Therapy Products.

I bought one for our baby's room, but when I decided I wanted one for myself, I hit on a much cheaper solution; I just turn my clock radio to an empty station and crank the volume.

Punch holes in the blades with a drill.

That and (perhaps) making the pattern asymmetric should restore the noise.