FaceTime audio when blocked? If you're blocked as a contact on a iPhone can you still contact them by FaceTime audio?
No. Blocking a number will block it for normal calls, FaceTime and FaceTime audio.

You might have to pay attention to the details though to fully block someone. Anyone using FaceTime has an AppleID so you'd want to block the Apple ID (usually it's an email) and possibly also block the associated cellular number(s) since you can attach several phone numbers to one Apple ID.