When Marty Jr. gets home, he approaches the large video display in the living room, which is displaying a cropped image of “The Gold of Their Bodies (Et l’or de Leur Corps)” by Paul Gauguin. He speaks to the screen, saying Art off. After a bit of static, the screen goes black. He then says, OK, I want channels 18, 24, 63, 109, 87, and the Weather Channel. As he says each, a sixth of the screen displays the live feed. The number for the channel appears in the upper left corner for a short while before fading. Marty Jr. then sits down to watch the six channels simultaneously.
Voice control. Perfect recognition. No modality. Spot on. It might dynamically update the screen in case he only wanted to watch 2 or 3 channels, but perhaps it is a cheaper system apropos to the McFly household.