Cannot play sound effects while connecting or disconnecting a call

[dfed]

Describe the bug
Enabling or disabling the microphone on a LiveKit room affects the audio stack such that playing sound effects or background noise across these events is user-visibly broken.

SDK Version
2.0.12

iOS/macOS Version
Tried on multiple iOS 17 versions, including most recent at time of writing: 17.5.1.

Xcode Version
15.4.0

Steps to Reproduce

1. Download + open sample project
2. Set a valid room and token under the // Set your token here comment
3. Run app (device or simulator – both repro)
4. Tap "Play audio"
5. Tap "Connect" Result: audio audibly glitches when the microphone connects
6. Tap "Disconnect" Result: audio stops playing entirely
7. Tap "Stop audio"
8. Tap "Play audio" again Result: app crashes because the player has not seen an I/O cycle. This is because disconnecting has effectively stopped all audio – calling pause() and then play() on the audio engine after disconnecting fixes this crash.

Expected behavior
Background audio can play without distortion or stopping across enabling/disabling the microphone.

Though I'll take a workaround to at a minimum let me play sound effects without distortion.

Screenshots
N/A. Sample project attached

Logs
N/A. Sample project attached

livekit-swift-example-collection-audio.zip

[dfed]

Upon further testing the audio issues above occur when calling room.connect(...) and room.disconnect(), regardless of whether room.localParticipant.setMicrophone(enabled: true/false) is called, even when AudioManager.shared.customConfigureAudioSessionFunc is set to no-op.

[bcherry]

@dfed we made some changes and improvements to this behavior in recent versions of the Swift SDK. Can you let me know if you still experience this problem?

[dfed]

@bcherry glad you're investing here! I tried pointing the sample project attached to the OP to both latest main (4a74cf4) and the latest release 2.0.16: the project is still exhibiting the same behavior described in the OP – the form of the distortion may have changed the playback is still quite distorted.

Let me know if you have issues running the sample project – it clearly reproduces the issue when running on an iOS device. The distortion is relatively minor on simulator when I tested tonight, so maybe there were improvements within the simulator environment?