Hear is my take from someone that is hearing impaired. My hearing loss in one ear was not related to damage due to noise exposure but I have significant hearing loss in my right ear and fairly severe tinnitus.
The noise cancelling is pretty good for what they are and I find them great for stuff around the 85-90db range. Like someone mentioned on an airplane they are amazing and make flying much better, I wish they had the feature to connect to the plane entertainment screen.
I do use mine a lot around the garage and yard for the typical stuff, electric lawn mower and string trimmer, drill, sander, nail guns, etc. If I am going to be doing something that is louder, or for an extended time I opt for the "foam earplugs" and my bone conducting headphones (shokz is the brand I have).
Now, when it comes to how the Pro 2's work as a hearing aid...not impressed. I was really really hopeful but they just don't give you the ability to tune them properly for what you need/want. The "report" it gave me after taking the hearing test was actually pretty accurate and matched what my real hearing test was but comparing the airpod to a real hearing aid was not even close. Good hearing aids are expensive though and I really really wanted this to work. Don't get me wrong, it does help but like the other person said the highs get amplified a lot, it seems. For example, closing the airpod case is crazy LOUD! You hear that thing snap shut for sure!
At the end of the day, I use them a lot and am happier with them than any other ear phones I have used and the noise cancelling is a plus.