Your Voice's Spectrum
Everything so far used made-up signals. This one uses you. Your phone is doing a real Fourier transform thousands of times a second — point it at your own voice and watch the frequencies light up live.
See the sound you're making
Tap Start, allow the microphone, then hum a steady note. The graph is the spectrum of whatever your mic hears: frequency runs left to right, and the height shows how much of each frequency is present right now. The tallest peak is your pitch — we'll name the musical note for you.
Hum, sing or whistle 🎤
Nothing is recorded or sent anywhere — the audio never leaves your device; it's analysed in the browser and thrown away. Tap Stop to release the mic.
What you're looking at
One note, many spikes
Hum a single steady note and you won't get one spike — you'll get a tall one plus a row of evenly spaced shorter ones. Those are harmonics: the pitch you hear is the lowest, and the rest are what make your voice sound like you and not a flute.
This is Build-a-Wave, backwards
In Build a Wave you added harmonics with sliders to make a shape. Here the transform reads them straight off a real sound. Same recipe of sines — measured instead of chosen.
Try it: whistle and you'll see almost a single clean spike (a whistle is nearly a pure sine — few harmonics). Then sing "aah" and watch a whole forest of harmonics appear. Slide your pitch up and the whole pattern marches to the right. You're watching ĝ(f) update in real time on your own voice.