Why Sound Waves - Why NOT just data?

[BrockMcKean]

I thought the entire system was dependent on microphone feedback from a capacitive sensor that discharges every time the resin drips through? How will it work well via smart phone if it does not have the separate I/O channels to control the laser and the resin level? I assume it's not needed if the drip reservoir is a specific shape and volume but I thought that was intended to be a separate part and not included with the kit?

[Compro01]

I thought the entire system was dependent on microphone feedback from a capacitive sensor that discharges every time the resin drips through? How will it work well via smart phone if it does not have the separate I/O channels to control the laser and the resin level? I assume it's not needed if the drip reservoir is a specific shape and volume but I thought that was intended to be a separate part and not included with the kit?

Ever notice how some of the earphones included with smartphones has a microphone in it? Most smartphone "headphone" jacks are actually TRRS connectors. They function as both headphone jacks and microphone jack.