The recommended earphones I ordered will be arriving on Monday and I will probably give this a go, very carefully at first. Though I'm having a bit second thoughts. Let me explain why.
I asked the same question about MuteButton, and it later came out it doesn't help hyperacusis and there was a misunderstanding. He used the phrase "knocks out the tinnitus". Well tinnitus and pain from hyperacusis are not completely useless.
Hyperacusis probably has evolutionary reasons, one's ears are severely damaged and it's like a wound, your brain is trying to make sure you don't get further damage.
If a person using this sound gets relief from hyperacusis, and the physiology of the ears is not changed in the 3 weeks or less that it takes to get rid of tinnitus and hyperacusis, I can totally see how using it could give people a false sense of security.
It'd be most apparent in the extreme cases of hyperacusis. My hyperacusis is not that bad (anymore), but still I could find myself in situations that would cause pain and I should leave or find protection but wouldn't because I'd have no way to gauge if it's damaging my ears.
I'm pretty careful when it comes to stuff like this, I'd still protect after "curing" my hyperacusis and tinnitus in loud places. But some people, especially if they had bad hyperacusis before, might just think they're fine now and end up damaging, possibly severely, their hearing and wouldn't even notice it because it could be gradual and there'd be no "warning signal".
People can't even read the instructions and follow them. There's also no disclaimer about you needing to still protect your ears if you do end up getting relief.
If it was just for me, then I'd rather have this sound work like MuteButton, helping tinnitus and not hyperacusis. Unless Mr. Case is claiming it actually heals the ears or that their physiology is changed in a few weeks, what I described can be a problem, especially in the severe cases of H and damaged ears.
So my concern is not so much about the sound causing damage itself. Maybe I'm missing something, if so, I'd be glad if somebody points it out.