I think in practice it's basically helping you come to accepting you have tinnitus because they can't do shit all about it, or understand why it happens in a bunch of cases.
There's a neural theory of tinnitus, that says you hear it because your brain is compensating for lack of signal at some frequencies.
Like the amplifiers are turned up to max at some frequencies, and the neural net maybe even adds an interpolated perception.
If that theory has anything to it, it makes sense that it might be possible to train your brain to reduce the effect.
That's not just "accepting", but it might be difficult to perceive a difference if "accepting" results in "not noticing as much", and "not noticing as much" is indistinguishable from "turning down my brain's perception gain for these signals".
