Can iOS restrict app access to audio out?

I use digital hearing aids. My hearing aids are not “Made for iPhone”, and connect to my iPhone via Bluetooth. They are set as the default audio out for phone calls, audio notification alerts, and music/video/podcasts, which is what I want.

But I’d like to have them not be a default audio out for other apps. I play very few games that I want to have play audio, and I turn the audio volume to zero, or uncheck in-app audio altogether, in most games.

This is a problem with my hearing aids, though, because even with the in-app options for audio disabled, many games still connect to the audio output. So when I launch those games, my hearing aids automatically switch into a mode where they’re conveying less sound from my environment so that I can hear the sound that the app is telling them should be coming from the phone.

This was a mild annoyance before I got hearing aids, because it would also interrupt any audio I was playing via another app (such as music or a podcast) while I was playing the game. But with my hearing aids now, it’s borderline dangerous, as my ability to hear my environment is restricted while I play these games. It also drains my hearing aids’ battery faster unnecessarily, because they’re maintaining an open Bluetooth audio stream that doesn’t actually contain any audio.

Not every game I play has this problem, so I know it’s something that developers should be able to put in their apps (that when sounds are turned off, the app doesn’t try to access the audio out at all), but most don’t bother, and the few I’ve contacted about the issue don’t seem to understand what I’m trying to convey the issue is (I’ll grant, a very large proportion of game developers are outside the US, and English is frequently not their first language).

With apps whose audio is permitted to play in the background, the lock screen and the Control Center show controls for changing the audio output device along with the controls for play/pause/etc. But they don’t show these controls for games that stop playing any audio when they go into the background (which is pretty much all games).

I’ve hunted through the Audio and Accessibility options in the Settings app and can’t find any way to restrict individual apps’ access to audio out or set preferred audio output devices for individual apps. The app which controls my hearing aids has modes automatically selected for phone calls, listening to music, watching video, and using the TV-audio accessory (connected to my AV receiver to send TV audio directly to my hearing aids), but I can’t find any way to create a program mode that will disable other apps’ ability to take over my hearing aids. I’ve done multiple Google searches for information about this and found nothing useful. My audiologist hasn’t been able to help with this either.

This is on an iPhone 7 Plus running iOS 15.4.1 (I will be upgrading to 15.5 soon), using Phonak Audéo M70-R hearing aids.

Does anyone know of any way to deny a specific app access to audio out or force it to use the phone’s speaker? If there isn’t any way to do it, would it be worthwhile to contact Apple to ask for this to be added to Accessibility options in iOS 16?

My digital hearing aids are “Made for iPhone”. I decided long ago NOT to make them the default for calls. My main issue was that I couldn’t find my phone when it was ringing! I would rather “transfer” the calls to my aids on phone calls. I wonder if this has kept me having your issue.

I do see that you have a “flight” mode on the Phonaks that keep the hearing aids working but turns off Bluetooth. Not the solution you want but if you are having safety issues and want to hear the world, that can be a quick, in-the-moment, step.

As to letting Apple know, I don’t think it will change much. I think they are pretty happy with the Made for iPhone program. My opinion only.