Rate 50 fpsEvents 14Flash 6 framesAudio 800→4000 Hz chirp, 80 ms

1. Turn the volume up enough that the phone will hear the chirps clearly.
2. Press Play with sound, then Fullscreen.
3. On the phone open the scanner, frame the screen so the flashing area fills most of the view, and press Start measurement.
4. Measure a baseline this way first — that is the phone's own camera-to-microphone skew. Store it, then measure the system under test.

This page is the reference signal, so what it measures is the whole loop: this screen and these speakers, plus the phone's own capture. It is not a measurement of anything else until a baseline or device profile for the phone is applied.