A button, it would look really weird if you talked to your TV and it could be so easily activated by others if they wanted. Any could activate a TV with their voice and it would be problematic. There is only remote, so yeah press a button
Xbox One, PS4 and Switch (+ Many Retro Consoles)
'When the people are being beaten with a stick, they are not much happier if it is called the people's stick'- Mikhail Bakunin
Prediction: Switch will sell better than Wii U Lifetime Sales by Jan 1st 2018