By how much can video and audio be out of sync?

2018-10-22 21:00:02

If I have an interview or lecture style video and the audio is out of sync, by how much can it be out of sync before the average person would easily notice?

I'm currently trying to create an HTML5 player that sometimes has the video and audio in separate elements, meaning the video and the audio buffer and play at separate times. I've developed a decent code that keeps them synced (it's a harder problem then it should be). The current code pauses the video and the audio elements if they are off by 0.1 seconds, adjusts the time of the video element to the audio element, waits for oncanplay event, then plays both. My question is whether 0.1 seconds off in audio/video sync is too much. Would a common user notice a 0.1 seconds sync disparity? What's the highest I can go before the common user might notice the lips don't quite match the voice? Does any large organization have an official standard on this?