Well I think I will add two additional experiences using my hearing aids.
For years I have had pulsating tendonitis, where it sounds like waves breaking on a sea shore. When I started wearing my hearing aids, just inserting the slim tube tips into my ears made the sound almost disappear. This is without even turning on my hearing aids. I think the rubber cones changed the internal pressure in the canal, and reduced the pulse from my heart beat.
About 15 years ago, long before wearing hearing aids, I kept hearing what guitar players would call a “fret buzz” around the E & F on the high E string. I could never get rid of it, and it made everything sound so bad I just quit playing. Last year after a month or two learning to program my Phonak Bolero V70s, and refining the music settings, I pulled out my classical guitar, played it, and of course there was the fret buzz. I switched to my music program, and the buzz was gone. When I was working on the music settings, I just wanted to better listen to music, not even thinking about the guitar problem. I have no idea what’s going on, but I am thrilled with the unexpected results.