Competitor?, page-7

This has been brought up before in previous discussions.

My understanding is they are using MEMs devices to construct a mini analog speaker.

A piezo electric device takes an analog electric signal and converts into a physical movement, just like a voice coil/magnet on a typical speaker.

Audiopixels is using digital sound reconstruction from an array of MEMs pistons. The pixels (pistons) are digital (i.e. on/off). They don't vary in amplitude in response to an input signal.