This has always reminded me of Ben Rubin's (EAR Studio) early work on notification tones. One of his projects was the ticket gates in the NYC subway system. Th

This has always reminded me of Ben Rubin's (EAR Studio) early work on notification tones. One of his projects was the ticket gates in the NYC subway system. Those high-pitched piezo speaker beepers are cheap and simple, but it is difficult to localize where the beep is coming from, and the single frequency can't communicate much. Mostly, you can't tell if your gate beeped, or the one next to you. His solution was, among other things, to turn it from a beep to a bell tone. That alone made it better. It seems like the audio design of things is often missed. I'm excited about products like Google's Home and Amazon's Echo because we're finally considering audio as a first-class user interface.