Reply To: AirPods Pro 2 Spatial Audio volume drops softly whenever MacBook notification chimes

Diagnosis: WindowServer focus changes (kCGWindowWorkspaceNotification) do not drive audio ducking; coreaudiod owns the kAudioSessionInterruption duck triggered by Slack’s NSSound playback. Audit login items for legacy launchagents injecting code into coreaudiod (sudo launchctl list | grep -i audio), but the root cause is the Mac advertising kBluetoothHandoffCapable=true to the AirPods firmware. Mitigate by killing coreaudiod (sudo pkill coreaudiod) after setting the manual connect preference to flush the cached Handoff token.