Tone Generator
Play one tone or up to eight at once, at any frequency from 1 Hz to 20 kHz, as a sine, square, triangle or sawtooth wave. Watch the wave and its spectrum, build chords and binaural beats, run sweeps and pulses, and save the sound as a WAV file. No app to install and no account to create.
Generate a tone
Start at a low volume, especially with headphones. Square and sawtooth waves carry more energy than a sine at the same setting, and tones around 2 to 5 kHz, where hearing is most sensitive, feel loudest. Space bar plays and stops.
Plays this tone in the left ear and a slightly higher one in the right. Use headphones.
Switches every tone and sweep on and off with 5 ms fades, on the audio clock. Keypad tones are not pulsed.
A speaker check: play a low tone such as 100 Hz and compare. With speakers wired correctly, the normal setting sounds centered and full, and the flipped one wide and thin in the bass. If it is the other way round, one speaker is wired backwards.
Presets
Hearing is commonly given as 20 Hz to 20 kHz, and the top end falls with age. Whether a tone is audible also depends on your speakers, so this is a curiosity, not a hearing test.
Builds the chord in equal temperament from the tone you are editing, each note a tone of its own.
An auditory illusion: a different tone in each ear is heard as a slow beat. A 2023 systematic review of 14 studies found the evidence that the beats entrain brainwaves inconclusive, so treat it as a sound, not a treatment.
Phone keypad
Each key plays its row and column tone together (DTMF, ITU-T Q.23) for as long as you hold it. Dialed digits play for 100 ms with 100 ms gaps.
Sweep
Steps use the standard band centers around 1 kHz (IEC 61260) or the notes of the tuning. Mark, or the M key, notes the frequency you hear at that moment: a rattle, a room resonance or where a tone fades out.
Save as WAV
The file holds exactly what plays: every tone with its level and balance, the volume, pulse and polarity. One sweep is a single pass (up and back for Up and down); keypad digits are the digits in the dial field. Mono averages the left and right channels and leaves out the polarity flip.
Share and keep
The link carries the sound: tones, volume, tuning, pulse, polarity and sweep. Saved sounds do too, and stay in this browser on this device.
Hear nothing on an iPhone? Check the ring/silent switch, which can mute web audio.
Keyboard shortcuts
- Space
- Play or stop
- ← →
- Fine tune by the chosen step (Shift: ten steps)
- ↑ ↓
- Up or down a semitone (Shift: an octave)
- M
- During a sweep: mark the frequency you hear
- Enter
- In a frequency field: play
The frequency field also takes kilohertz (1.5k) and note names (A4, C#3, Bb2), tuned to the A4 you choose.