I feel for you, but in this case it sounds reasonable, at least as a first step. OTC medicines tend to be less potent than their prescribed counterparts. This is to protect people who don't know what they need from themselves (and many other reasons).
You are going to have tons of new low quality new options, and setting hard limits on their potential damage to new users (either due to misuse or poor design) seems like a good approach until the dust settles.
This is such a cop-out. It basically sounds like they're just going to be ordinary earphones then. Even ordinary earphones will damage your hearing at the highest outputs; damage comes long before "ear-splitting" / painful levels. If the regulations permit levels that are sufficient for moderate hearing loss, some mild users will program the levels too high and make things worse.
There are reasonable limitations to be made here: requiring initial settings to be low, restricting how quickly volume can be increased while they're being programmed, having different drivers for different levels of hearing loss (which is already the case for prescription hearing aids), etc. But individual responsibility is fundamentally both a requirement and reasonable presumption. We don't let people who commit suicide by swallowing a bottle full of sleeping pills prevent the rest of society from having access to sleeping pills, nor would we presume that a prescription magically stops people from getting suicidal. Yet the consequences for misprogramming OTC hearing aids are much lower than the consequences for not taking sleeping pills as directed.
Hearing and vision are both very sensitive senses, that are easy to permanently damage.
Everyone should have access to treatment they need, but having a licensed doctor review severe cases to find the right fit and prevent further degradation or full deafness, especially if their hearing is already weak, is a reasonable safeguard.
You can use an app to check which frequencies are missing. The man with the bit of paper will be doing the same thing.
I may be biased as I work on a medical device and at least for the device I work on the doctors signing off are contributing nothing more than their license.
But also it's protection to prevent you from further damaging your hearing, just like most drugs require a prescription.
The real problem isn't the regulation requiring professional oversight of potentially damaging devices (or medications), but the fact that medical care is affordable for many.
You are going to have tons of new low quality new options, and setting hard limits on their potential damage to new users (either due to misuse or poor design) seems like a good approach until the dust settles.