toneglass

A LITTLE GAME OF LISTENING

What’s that note?

A fan. A piano. The sound you can’t unhear.

Ready to listenA4 = 440 Hz

MUSICAL PITCH · ESTIMATE

A note will appear here

Hz

Nearest note, plus the distance from it

Allow the microphone when asked. Nothing is recorded or uploaded.

On the keys

C3 — B5
The detected note lights up here.C4 · middle C

Fundamental level

Waiting for a tonedBFS · RMS estimate

Fundamental band only · thin line holds its recent high · digital level, not room dB SPL.

See what you hear

A window into the sound around you.

Start listening, or explore a demo.
40 Hz — 8 kHz · logarithmic15 seconds → now

Tap a bright line to inspect its frequency.

Also in the sound

Tap a tone to follow it

Steady tones will appear here as we listen.

A few notes on listening

For your game: let one person hold the phone near the sound. Hide the answer, make your guess, then freeze and reveal. The big letter is the nearest musical note; the number is the estimated frequency. Middle C is C4, about 261.6 Hz.

Hear the family. Musical pitch mode groups steady peaks at roughly 2×, 3×, 4× and other multiples of a common frequency. That helps keep a bright overtone from replacing the underlying note. When the fundamental itself is absent, a supported estimate is labelled “Inferred.” Individual tones and Strongest modes are available under Adjust view.

A useful estimate, not a verdict on your ears. Multiple sound sources, inharmonic sounds, and weak signals can still confuse the estimate. The method is a harmonic heuristic, not a complete model of human hearing. Other candidates appear below so you can choose the one you mean.

Keep it local. Audio is analysed in memory on this device. There is no recording, audio storage, upload, or account. View preferences are saved on this device. On iPhone, open in Safari, then Share → Add to Home Screen.

Microphone off. The app requests noise suppression, echo cancellation, and automatic gain control off when your browser allows it.