Just read about this app in
@Hazel's recent update. I'm going to try it! I have reactive tinnitus and had lots of trouble with masking. It was so frustrating as everyone talks about masking, but my tinnitus always wins...
The best app for me, so far, which this app may be able to borrow some ideas from, is "Tinnitus HQ-ear ringing relief."
The matching interface was intuitive for me as I could easily drag the bar and widen or narrow the frequency band easily. So, I had some luck notching.
There's a lot of sounds you can mix together. I found a bit of bubbling lava, combined with a tiny bit of ocean waves, and a more twilight resonance, all dialed in at different levels, calms me the most, and doesn't react much.
It doesn't totally mask, but it's the best I've found so far, after what must be ten apps, including paid subscription services that made mine worse.