I had a very strange experience like that recently when listening to Radio 3, the BBC's mostly-classical channel. They had an opera programme with guest presenters from the Met Opera in New York. The usual BBC presenters of course have British accents, and one of these American presenters had a particular accent that my brain latched onto as matching the sound of synthetic speech. I just could not suspend disbelief and convince myself that this speech - which rationally of course I knew was human - was that of a real person rather than some sort of AI assistant. It was a very strange feeling.

I did have a fever at the time, which might not have helped.