@stefanator I just downloaded the app and tried on iOS 16.4. It seems that Apple has fixed this issue since I did not observe audio cutting in and out. Can you confirm?

I am seeing the same problematic 4 channel format on iPhone 14 when I set up Audio session in videoChat mode. Can someone from @Apple please comment on how to force default 1 channel / frame format

Facing the same issue on the 14. When I look at AudioStreamBasicDescription of the CMSampleBuffer that are received from videoChat mode on 14, I get this Optional(<CMAudioFormatDescription 0x283384820 [0x1f2fa8580]> { mediaType:'soun' mediaSubType:'lpcm' mediaSpecific: { ASBD: { mSampleRate: 44100.000000 mFormatID: 'lpcm' mFormatFlags: 0xc mBytesPerPacket: 8 mFramesPerPacket: 1 mBytesPerFrame: 8 mChannelsPerFrame: 4 mBitsPerChannel: 16 } cookie: {(null)} ACL: {Mono} FormatList Array: { Index: 0 ChannelLayoutTag: 0x640001 ASBD: { mSampleRate: 44100.000000 mFormatID: 'lpcm' mFormatFlags: 0xc mBytesPerPacket: 8 mFramesPerPacket: 1 mBytesPerFrame: 8 mChannelsPerFrame: 4 mBitsPerChannel: 16 }} } extensions: {(null)} }) When I initialize audio session in default mode, the CMAudioFormatDescription of audio samples is Optional(<CMAudioFormatDescription 0x282559540 [0x2021f4580]> { mediaType:'soun' mediaSubType:'lpcm' mediaSpecific: { ASBD: { mSampleRate: 44100.000000 mFormatID: 'lpcm' mFormatFlags: 0xc mBytesPerPacket: 2 mFramesPerPacket: 1 mBytesPerFrame: 2 mChannelsPerFrame: 1 mBitsPerChannel: 16 } cookie: {(null)} ACL: {Mono} FormatList Array: { Index: 0 ChannelLayoutTag: 0x640001 ASBD: { mSampleRate: 44100.000000 mFormatID: 'lpcm' mFormatFlags: 0xc mBytesPerPacket: 2 mFramesPerPacket: 1 mBytesPerFrame: 2 mChannelsPerFrame: 1 mBitsPerChannel: 16 }} } extensions: {(null)} }) This shows that audio session is sending CMSampleBuffer objects that are now fundamentally different (this new format is not handled by AVAssetWriter and I get an error upon calling AVAssetWriter.append.

We are seeing the same issue on iPhone 14 and basically iOS app is broken at this point.