I believe the problem is most audiologists are trained to help folks communicate. It’s not that the hearing aids won’t work well for musicians, it’s just that most audiologists are reluctant to disable the digital features that work so well to help communicion in most environments.
I recently ran into a situation affecting the dedicated music program on my Phonak Bolero M90 aids with Bluetooth. When the music program was activated, I could hear a slight hiss in my right ear only. I never heard it in my older Phonak V70 aids without bluetooth, so I went back and added a little noise canceling to my right ear in the music program, which fixed it.
Because the right side is the one set to communicate via bluetooth with my phone, I was hearing some noise that probably would never be heard in any of the other programs with all the normal digital functionality operating. My older V70 aids do not have bluetooth, so no hiss. I plan to verify this by using the target software to switch the bluetooth to the left ear and see if the hiss follows it.
The hiss was present even with my phone turned off, so I know it’s in the hearing aids.
The addition of a little noise canceling didn’t seem to adversely affect the sound of my guitar.