While there are several solutions to problematic audio syncing between audio and video playback, Apple wants to make it easier for users to fix the problem with Apple TV. Starting with iOS 13, users will be able to fix any audio sync related problems you might have with your Apple TV videos.
Named Wireless Audio Sync, the feature will use an iOS device to measure the difference between audio and video in your Apple TV. In order to do so, Apple TV will play a series of sounds which will be picked up by your iPhone to measure the time required to hear the sounds. Afterwards, your phone will try to determine if there’s an audio sync issue with the playback and in case it finds the problem, the phone will calibrate the audio and video to solve the problem.
According to 9to5mac you will need to perform this recalibration once. Understandably, you will need to repeat the process in case you change your equipment. Given we will have to wait a while before iOS 13 release, it’ll be interesting to see if the feature becomes popular among consumers upon its arrival later this year.