What your body does while you think about a question.
This page plays a sound just above hearing from your speaker and listens for it with your microphone. When you move, the echo changes. That is all it measures.
Nothing is recorded and nothing leaves your laptop. The trace is drawn on this screen only.
01A laptop, not a phone
02No headphones. Take them off, the sound has to travel through the room
03Volume up, a quiet-ish room
04Two minutes with nothing else open
Firefox filters out the laptop's own sound and cannot be told not to. Chrome or Safari, please.
Starting the sound
Sit with it. There is nothing to do here.
This is what your body did while you thought about it.