Here's how you can use FaceTime Audio on your iPad, iPhone or iPod.
1. Open the FaceTime app.
2. Tap on Contacts.
3. Select the person you want to call.
4. Tap the FaceTime phone icon to make your audio call.
Using FaceTime for audio calls only can be quite useful if you prefer not to have the other person see you by using video. It can also obviate the need to hold your iOS device so that your face appears properly for the person when using Facetime's video calls.