You can hear plenty of sound from the outside, most of it in the lower frequency bands and sometimes only via bone transmission, but it's there. Get a pair of a

You can hear plenty of sound from the outside, most of it in the lower frequency bands and sometimes only via bone transmission, but it's there. Get a pair of active noise-cancelling headphones and try it for yourself, especially in more complicated driving situations. While the brain can still operate a car with the loss of some input, visual input isn't really enough and is heavily supported by all other senses (acceleration and gravity, sound, touch and vibration, temperature and kinesthetic). Unlike modern computers, the brain is massively parallel and asynchronous, so it can simply use all of the inputs to find the correct course of action, even going as far as considering multiple lines of thoughts (and then your memory is manipulated so you only experience the chosen line of thought, similar to your vision being manipulated when you blink).