I was wondering why they didn't use USB or something similar. How will they interface with, e.g. laptops or phones that don't have a microphone jack? If they're committed to using audio to drive the device, what about a usb audio device, similar to a usb headset with microphone?

On the other side of the concept of using audio as their output system, what would a cube sound like if played through speakers instead of through their printer? And how would a Mozart symphony look when printed?