Does a FaceTime call interrupt a voice recording on iPhone?

It is a reasonable thing to wonder about. FaceTime does not arrive through a SIM card, does not show up as a carrier call, and can run entirely over Wi-Fi with no phone signal anywhere nearby. None of that turns out to matter for whether it interrupts a recording, because the part that matters is not how the call got there — it is what it does once it has.

Why it counts as an interruption at all

iOS treats the microphone as one resource that only one thing can hold at a time, arbitrated by a system-wide audio session rather than by each app individually. A FaceTime call, audio or video, needs that same microphone, so the system takes the audio session away from whatever currently has it and hands the app a notification that an interruption has begun. That is the identical mechanism a cellular call, an alarm, or Siri uses — FaceTime is not a special case that gets to skip it, it is just one more thing in line for the same resource.

This is also why the interruption starts the moment the call arrives, not the moment you answer it. Declining a FaceTime call, the same as declining a phone call, stops the ringing sooner, but the system has already taken the microphone by the time you see it on screen.

Video versus audio-only FaceTime — the microphone does not care

FaceTime Audio and FaceTime Video ask for different things from the camera, but they ask for the exact same thing from the microphone. Whether the call ends up showing video or not, it still needs live audio input and output, and it still goes through the same audio session the system hands out to one thing at a time. A recording pauses for a FaceTime Audio call exactly as readily as it does for a video one — there is no version of FaceTime that leaves the microphone alone.

Starting a FaceTime call yourself

Everything above describes an incoming call, but the mechanism is not one-directional. Placing an outgoing FaceTime call while a recording is running takes the microphone the same way an incoming one does, because from the audio session's point of view a call is a call regardless of who started it. The practical difference is just that you did it on purpose — an outgoing call is rarely an accident the way an incoming one can be, so this is more a thing to remember than a thing to guard against.

Group FaceTime

Being added to or joining a Group FaceTime call reaches the phone the same way a one-on-one call does — as an incoming call the system has to hand the microphone to, however many other people end up on it. Nothing about a call having more participants changes what happens at the audio-session level; it is still one call, one interruption, one microphone handoff.

Why Airplane Mode is not the complete fix here

For a cellular phone call, Airplane Mode is close to a full answer, because it cuts the cellular radio a normal call needs to reach the phone at all. FaceTime does not rely on that radio — it runs over the internet, whether that is Wi-Fi or cellular data, so a phone sitting in Airplane Mode with Wi-Fi switched back on can still receive a FaceTime call and still have it interrupt a recording. Turning off Wi-Fi as well, not just enabling Airplane Mode, is what actually removes the path FaceTime uses to reach the phone. A phone with no internet connection at all, cellular or Wi-Fi, cannot receive a FaceTime call in the first place.

How Voice Studio handles it

Voice Studio watches for the same system interruption notification no matter what caused it. On the "began" signal it pauses the recorder, keeping everything captured so far. On "ended" it re-activates the audio session and resumes recording into the same file, so a FaceTime call in the middle of a recording leaves a gap rather than two separate files — the same outcome as a cellular call, an alarm, or any other interruption the system can throw at it.

Common questions

Does a FaceTime call interrupt a recording the same way a phone call does?

Yes. Both reach the microphone through the same system-wide audio session, and the system takes that session away from a recording app the moment either kind of call arrives, whether or not you answer it.

Does it matter if the FaceTime call is audio-only or video?

No. Both ask for the same live audio input and output, so both take the microphone the same way and interrupt a recording identically. The camera is a separate resource that has no bearing on this.

Does starting a FaceTime call myself interrupt my own recording?

Yes. The audio session does not distinguish between an incoming and an outgoing call — either one takes the microphone away from whatever was using it, recording included.

Does Airplane Mode stop a FaceTime call from interrupting a recording?

Not by itself. FaceTime runs over the internet rather than the cellular network, so if Wi-Fi is switched back on while Airplane Mode is active, a FaceTime call can still get through and still interrupt a recording. Turning off Wi-Fi as well removes the path it needs.