I think this is a Google Translate feature, and one of my favorite examples of "Do what I mean" UX. If you click again, for any word, it guesses that you didn't

I think this is a Google Translate feature, and one of my favorite examples of "Do what I mean" UX. If you click again, for any word, it guesses that you didn't get the pronunciation the first time, so it speaks slowly. This is what humans would do too, in this situation.