Press play to run a Hann-windowed 2,048-point FFT on the playhead every frame and draw the magnitudes in decibels, with the tallest bin and the per-frame FFT time read out. The sandbox has no microphone, so the sources are synthesized: a sweep over a 440 Hz drone, a chord of harmonics, white noise with a hidden 1 kHz tone, and a short song built from a few harmonics.
The claim above is what this widget demonstrates. Disagree with it?