Whispers of a working chip, page-136

Imagine, as Danny shows in his promo ad, a single clap as being a single pixel actuating, and when lots pixels actuate simultaneously it is like lots of claps at the same time - i.e. a much louder CLAP. But this happens at 200KHz, so the "sound" of all those claps adds up to a sizeable punch of sound. These are then shown as the stacked pulses of sound in the video that when added together, both stacked in number but also stacked over time, fill in the far longer sine-waveform of much lower frequency sound - i.e. audible sound. Lots of fast ultrasonic pulses can be delivered as to create sound of much lower wavelengths. These cover the whole audible frequency range we can hear.