iPhone 12 and iPhone 12 Pro users experiencing audio issues may be able to send their devices in for repair for free.
iPhone Can’t Hear Calls Unless On Speaker? Here’s the Fix!
Apple has acknowledged that some iPhone 12 and 12 Pro devices are experiencing audio issues, likely due to a defective component in the receiver. If your iPhone has a defective component in the receiver, it will specifically not emit sound when placing or answering calls. If your device was manufactured between October 2020 and April 2021, it may be affected.
Apple's "iPhone 12 and iPhone 12 Pro Service Program for No Sound Issues," however, only applies to the iPhone 12 and 12 Pro. Neither the iPhone 12 mini nor the iPhone 12 Pro Max are eligible, though they shouldn't be affected either.
If you believe your iPhone 12 or 12 Pro is defective, Apple will repair it for free.