Is it possible to perform speech-to-text using AVAudioEngine to capture microphone input while being on a FaceTime call at the same time? I tried implementing this, but whenever I attempt to start the AVAudioEngine while a FaceTime call is active, I get the following error: “The operation couldn’t be completed. (OSStatus error 2003329396)” I assume this might be due to microphone resource restrictions during FaceTime, but I’d like to confirm whether this limitation is at the system level or if there’s any possible workaround or entitlement that allows concurrent microphone access. Has anyone encountered this issue or found a solution?
AVAudioEngine fails to start during FaceTime call (error 2003329396)
Right now I've got the same error and don't know how to handle it. But in my case I'm recording audio on the Apple Watch with AVAudioEngine. I minimized the app during recording and started 1sec timer. When timer fires, I'm getting interruption began event where I pause recording, when I stop timer's alarm, I have interruption end event with shouldResume and I'm trying to do AVAudioEngine.start(). That's where I have this error.
I hit a very similar issue while building ambient-voice — a real-time speech-to-text macOS app using SpeechAnalyzer.
AVAudioEngine.inputNode.installTap() worked fine with built-in mics but silently failed with Bluetooth devices (the tap callback never fired). The root cause is similar to yours: audio session resource conflicts.
Our fix was switching from AVAudioEngine to AVCaptureSession. The captureOutput(_:didOutput:from:) delegate fires reliably regardless of audio device state or competing audio sessions. The tradeoff is you get CMSampleBuffer instead of AVAudioPCMBuffer, so you need a conversion step — but it is straightforward.
For your FaceTime case specifically, AVCaptureSession with .mixWithOthers category option should let you capture mic input without conflicting with the active call audio session.
We documented all the audio pitfalls we hit on macOS 26 in our forum post: https://developer.apple.com/forums/thread/819525
The project is open source: https://github.com/Marvinngg/ambient-voice