We're building a companion app that people use during a regular cellular call (VoIP isn't an option for this call). The user wants to briefly mute the call, speak a short question into our app, then unmute. Is there any supported way for a third-party app to record from the microphone during an active cellular call, even if the call is muted or on hold? Does Siri with App Intents accept voice input during an active call? If so, is Siri's spoken response heard by the other person on the call? Can a watchOS app record audio while the paired iPhone is on a call? If none of these work, what approach do you recommend?