>That's why most codecs have packet loss concealment (PLC) that can fill in for missing packets with plausible audio that just extrapolates what was being said and avoids leaving a hole in the audio
...How far can ML PLC "hallucinate" audio? A sound , a syllable, a whole word, half a sentence?
What the PLC does is (vaguely) equivalent to momentarily freezing the image rather than showing a blank screen when packets are lost. If you're in the middle of a vowel, it'll continue the vowel (trying to follow the right energy) for about 100 ms before fading out. It's explicitly designed not to make up anything you didn't say -- for obvious reasons.
You never can when lossy compression is involved. It is commonly considered good practice to verify that the communication partner understood what was said, e.g., by restating, summarizing, asking for clarification, follow-up questions etc.
It can already fill in all gaps and create all sorts of audio, but it may sound muddy and metallic. Give it a year, and then you can't trust what you hear anymore. Checking sources is a good idea in either case.
...How far can ML PLC "hallucinate" audio? A sound , a syllable, a whole word, half a sentence?
Can I trust anymore what I hear?