No, it only speaks the result if there is single answer to say. If you ask it what is 15% of 51 it will speak the result. But if you ask a broad question (what is quantuum mechanics) it will just list all results.
I can the "i" button in that video, but my app does not have it, and I don't get voice answers.
Edit: Switching to English (US) does give vocal answers, but then it doesn't seem to understand my South African accent anymore.