5.9.2. How It Works
It’s easier to understand what’s going on here if we think about it as two separate setups. Let’s call them “hard,” for the case in which you’re looking at the television right by the amplifier and “easy,” when you’re looking at the screen put a little further away.
In the hard case, there’s a video of a talking head on the television screen and two different voices, all coming from the same location. The reason it’s hard is because it’s easier to tune out of one information stream and into another if they’re in different locations (which is what [Hack #54] is all about). The fact there’s a video of a talking head showing in this case isn’t really important.
The easy setup has one audio stream tucked off to the side somewhere, while a talking head and its corresponding audio play on the television. It’s plain to see that tuning into the audio on the television is a fairly simple taskI do it whenever I watch TV while ignoring the noise of people talking in the other room.
But hang on, you say. In Driver’s experiment, the easy condition didn’t correspond to having one audio stream neatly out of the way and the one you’re listening to aligned with the television screen. Both audio streams were coming from the same place, from the amplifier, right?
Taken from : Mind Hacks
