I had the chance to see this incredibly cool Tesla electric car in action. I didn't get there in time to get to ride in it, but I did get to sit in it, which was a little like sitting in a kindergardener's chair. The car flew away like a bullet, and was completely silent. Where there should be an engine was a unit that looks like my window fan.
Sound is such an important part of our existence. We turn on the clicking noise on virtual keyboards and make our cell phones ring like old fashioned dial phones used to in order to find comfort in familiar sounds. One disturbing lack of sound is using a composting toilet (or a Portapotty) where there is no flusher.