The purpose of this post is to be on the record: In recent months I have been called many times in apparent attempts to get voice samples from me.
This is a known scam. I will not pay more attention to it for now.
Recently induced by circumstances of where I was (professional work meeting) and what I heard, I mistakenly said “yes”.
General advice: Hang up. Don’t talk.
Update: After conversations with professionals and after receiving yet another call with a different script, I considered these calls could have a different purpose. Just not certain either way. Don’t talk and hang up anyway.
Update #2: Meanwhile have learned, there is reason for concern. E.g. Adobe’s Project VoCo:
There is at least one other supplier of a similar tool.
Update #3: Fell for it again five months later. Unknown caller said something that induced me to say “yes” and a few words.
Update #4: Fell for it again more than a year later. Unknown caller said something that induced me to say “yes” and maybe a few words. Still not sure who is after what. At that frequency and patterns, there is something behind it. Here I am not reporting every incident, there are many more I don’t bother writing down. While they could be after some kind of access to my phone, still voice sampling is a plausible explanation.