Playground · Spectrogram
Your voice, or a boiling kettle, drawn as a spectrogram.
Press start and the page draws what the microphone hears: time runs left to right, pitch goes up the side, and brightness is loudness. Hum and you get a stack of lines, the fundamental and its harmonics, with the note named at the edge. A whistle is a single line; “sss” is a cloud. Freeze the picture to look closely.
Spectrogram
not listeningHow it draws
Every frame takes a 4,096-point spectrum of the latest samples (under a tenth of a second of sound) and paints it as one column. The frequency axis is logarithmic, so every octave is the same height, which is why the harmonics bunch together towards the top. The white dot is the fundamental found by the tuner’s pitch detector, the fainter dots are where its harmonics should be, and the label is that pitch as a note. The screen holds roughly the last sixteen seconds.
What this page sends
Nothing leaves your browser. The microphone opens when you press start; each frame becomes one column of pixels on the screen, and the sound itself isn't kept. Once a column scrolls off the left edge it's gone, and no request goes to a server while this runs.