Start with these simple steps before assuming something is broken ...

FaceTime Audio provides an easy way to make voice calls without relying on carrier networks.

The familiar FaceTime ring is used when placing a call, and sound quality is surprisingly good for what is essentially a beta product. Voice clarity is on a par with other apps like Skype for iOS, ...

FaceTime offers support for video calls and audio-only calls. The latter requires a little more attention to create, but you might find it a better alternative to a voice call, with crisper audio and ...