You can test this yourself by initiating a FaceTime Audio conversation from an iPhone or iPad to your own Mac. Of course, FaceTime Audio goes both ways, so with the newest version of Mac OS installed on the Mac, it can also receive inbound phone calls using the service. If the Mac is calling an iPhone user with FaceTime Audio, the call quality will depend considerably on the recipients cellular reception, so like most other VOIP clients it’s best used when on wi-fi (not to mention to avoid the potentially heavy data use). The audio quality of FaceTime Audio is quite good, though users with greater bandwidth available to them will likely enjoy the most clear conversations. Tapping the red “End” button is enough to hang up the call, or you can just quit out of the app.

Unlike the large screen that remains visible during an active FaceTime Video chat, FaceTime Audio calls use a small window for active conversations.

Click the small phone icon alongside the contact name to initiate the FaceTime Audio call.

From the Contacts, Favorites, or Recents menu, find the person you’d like to start a FaceTime Audio chat with.

Open the FaceTime app in Mac OS, found in the /Applications directory (once opened you’ll need to turn the service ON if you haven’t done so yet).

To start a FaceTime Audio call from Mac OS X: How to Make FaceTime Audio Calls from Mac

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