AVAudioSession API for setting stereo orientation on supported devices (iPhone XS and above) is completely broken on iOS 15 betas. Even the 'Stereo Audio Capture' sample code does not work anymore on iOS 15. Even AVCaptureAudioDataOutput fails when setting stereo orientation on AVAudioSession. I am wondering if Apple Engineers are aware of this issue and whether this would be fixed in upcoming betas and most importantly, iOS 15 mainline.
Still not fixed in iOS 15 beta 5. Looks like iOS 15 main release is going to have broken stereo audio API
Still not fixed in iOS 15 beta 6!
I also happened to this issue.
No error detected, just silence.
Note:
Stereo Audio Capture sample code. https://developer.apple.com/documentation/avfaudio/avaudiosession/capturing_stereo_audio_from_built-in_microphones
This project always will not work unless the language setting of the device is set to English. For iPad, additional patches are required.
I already filed a bug FB9393169 and the status is updated as "Resolution:Potential fix identified - In iOS 15". Not sure what this means. Because if this will be fixed in main iOS 15 release, then I don't need to do anything. But if it will not be fixed in iOS 15.0, then I will need to immediately update app and disable stereo capture else I risk lot of 1 star reviews.
It is fixed in iOS15 beta7 !!