Anonymous ID: 63ea9b Feb. 15, 2018, 10:13 p.m. No.394287   🗄️.is đź”—kun

>>393980

Headphones? Bluetooth microphones? The speaker on the phone itself? There doesn't need to be a tuned driver anymore–they can just play the frequency over a speaker. They might change the shape of the chamber the speaker is housed in to create resonance.