Unexpected AVAudioSession behavior after iOS 18.5 causing audio loss in VoIP calls

After updating to iOS 18.5, we’ve observed that outgoing audio from our app intermittently stops being transmitted during VoIP calls using AVAudioSession configured with .playAndRecord and .voiceChat. The session is set active without errors, and interruptions are handled correctly, yet audio capture suddenly ceases mid-call. This was not observed in earlier iOS versions (≤ 18.4). We’d like to confirm if there have been any recent changes in AVAudioSession, CallKit, or related media handling that could affect audio input behavior during long-running calls.

func configureForVoIPCall() throws { try setCategory( .playAndRecord, mode: .voiceChat, options: [.allowBluetooth, .allowBluetoothA2DP, .defaultToSpeaker]) try setActive(true) }

We’d like to confirm if there have been any recent changes in AVAudioSession, CallKit, or related media handling that could affect audio input behavior during long-running calls.

The system is always changing, but I'm not aware of any specific change or issue which matches what you're describing. There is the issue (and workaround) described here, however, that wouldn't happen mid-call.

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Kevin Elliott
DTS Engineer, CoreOS/Hardware

Unexpected AVAudioSession behavior after iOS 18.5 causing audio loss in VoIP calls
 
 
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