While I instinctively dislike any "secretly spying" devices, phones could do that for a while now. I wouldn’t have much use for my watch doing it, but my nephew swears by taking notes on an ipad with an app that has a sort of a playback: essentially a play bar that recreates the note as it is written, with audio included. Being able to playback the lecture afterwards that way is a huge benefit over pure notes and I wish I had something like that when I was in school.