New in iOS 7 is the ability to make FaceTime Audio calls. FaceTime Audio works internationally and works on a Wi-fi network, or on a cellular connection. Using Facetime Audio sounds nicer than actually using the iPhone to make calls. FaceTime Audio sounds deep, and closer to the actual sound of the voice. Another benefit of using FaceTime Audio is that it is associated with your Apple ID and phone number and is built right into the core operating system. For example, while you are texting someone, and you want to make a FaceTime Audio call, you can press the Contact button in blue in the upper right hand corner:
Pressing the Contact button gives you three different options: an i for info, a video camera and a phone.
Pressing the i button shows you your contacts card. Pressing the video camera icon will FaceTime that contact so you will see their face. Pressing the phone icon will prompt you with either making a phone call or a FaceTime Audio call.
Then it will make a FaceTime Audio call.
You can also use Siri to make FaceTime Audio calls, by saying “FaceTime Audio Mark.”
Since you are using FaceTime Audio, instead of worrying about minutes for the calls you will have to worry about data being used. You are able to track your FaceTime data usage while tracking your device’s cellular usage. When FaceTime is listed it will not break it down: FaceTime audio versus FaceTime classic. Instead, it just gives you the data for all of your FaceTime use. To actually see how much data you are using per FaceTime call, open up the FaceTime app and make sure Recents is highlighted in blue down at the bottom.
Then tap on the blue i next to when FaceTime was initiated. It will show you how long the FaceTime call was, what type of FaceTime was used, and how much data was actually used.
There doesn’t seem to be any pattern, or any formula as to how many minutes equals how much data being used when it comes to FaceTime. Regarding FaceTime Audio, in Australia, a spokeswoman for Apple said FaceTime Audio is:
more about the quality of the call and international calls.
This same spokeswomen also mentioned that the amount of data used by FaceTime audio would vary depending on different factors including the type of network and if there is any congestion in the network. Senior consultant and telecommunications analyst firm Ovum Craig Skinner said Apple added FaceTime Audio to capture market share in the US, since a lot of customers still have unlimited data plans and they try to avoid having high voice plans. He also said,
For Apple [Facetime Audio] is more about locking people into their services and using it to call customers on other iPhones. In the US it is substantially cheaper to make the data call. If you are an iPhone customer calling another iPhone customer it is cheaper, but if you are calling an Android customer you have to pay more.
Source: The Sydney Morning Herald