They might be able to do a reasonable job of faking Biden's voice with AI or through another person imitating him, but still it's interesting how many people can pick that something isn't right in what is to them, a very familiar voice / person. Individuals speak with a certain rhythm, tone, cadence, pitch etc and individual voices have quite an interesting 'signature' that I think is quite difficult to mimic perfectly. When you listen to someone who speaks publicly often, and you have observed them for years, I think you tend to subconsciously file that information away and measure / evaluate a great deal from the 'data' collected over time. You don't just listen to how someone speaks, you listen to and feel the 'frequency' and energy of the voice and can often accurately discern emotional/mental state as well as physical; you can also often hear and feel lies and deception, which I think a lot of people can hear in spades in that clip where
'Joe' is speaking.
'Biden's' voice was way too 'bright' IMO for someone who is 'too sick from Covid' to face the American people and make a clear brief personal statement about his decision to withdraw from re-election. Such a big issue and so important to endorse the VP asap so their supporters feel clear and confident, but none of that information was delivered in person or with any openness or clarity - not even through any kind of visual recording. Just a 'break up' through X.
IMO, same as others have said... 'Joe' was too animated and it felt very unnatural; Kamala could barely contain her delight at the prospect of becoming POTUS she was absolutely buzzing. She didn't look like she was too concerned about ole Grandpa Joe who must really be 'awful sick' if he can't even appear live by video link for such an important issue.
I considered that it could be drugs and painkillers assisting with how he is feeling, and possibly creating some kind of uplifting 'delirium', but generally if you are really sick it shows in your voice, it's very hard to hide, often there is a weakness and vulnerability - moreso in elderly folk. And normally his voice shows that vulnerability anyway at the best of times and his speech is stilted. Kamala totally screwed up when she went to say 'recording', hilarious! Breaking into her signature crazy hyena laughter doesn't cover up the BS. People can feel the lies and the tension and realise some very bad actors are trying to pull the wool over the eyes of the world. Nothin' new there.