I've noticed a different timbre to his voice at times as well. One voice is deeper than the other. Don't know if that is acoustics or F both JBs.
It would be interesting to run electronic voice comparison tests. You can bet other countries have, and it's to their advantage to keep status quo. You can't dumb or corrupt down Joe Biden any further.
I've no problem with running doubles for security sake, but this ain't that.
Those latex Hollywood masks are probably hot and itchy.
I have noticed the different tone/timbre too. On a couple of different occasions, too. It did raise suspicions in my mind. Now days you don't know what is real and what is not.
Glad you brought that up.