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Online Tone Generator

Play a precise test tone at any frequency from 20 Hz to 20 kHz, in sine, square, triangle, or sawtooth waveforms. Find rattles, check speaker range, and compare channels, all in your browser.

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Tone Generator

Play a steady test tone at any frequency from 20 Hz to 20 kHz. Generated locally in your browser.

440Hz

Waveform

Volume - 30%

Use moderate volume. Do not use headphones.

The sound may help with trapped water or loose dust, but it cannot repair hardware damage. Stop if the phone behaves abnormally.

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What is a tone generator used for?

A tone generator plays a steady sound at one exact frequency, which makes it the precision tool of speaker testing. Where the speaker test plays fixed reference tones, the generator lets you choose any pitch from 20 Hz at the bottom of human hearing to 20 kHz at the top, so you can probe exactly where a speaker behaves badly.

Common uses include finding the frequency where a speaker rattles or buzzes, checking how low or high a speaker can actually play, comparing left and right earbuds at the same pitch, and rough-checking your own hearing range with the high presets. It is also handy for testing subwoofers, car audio, and Bluetooth speakers, not just phones.

How to find a rattle with a frequency sweep

Speaker rattles usually live at specific frequencies: a loose grille, trapped debris, or a damaged diaphragm resonates at some pitches and stays silent at others. Start the tone around 100 Hz at moderate volume and slide upward slowly. When the buzz appears, you have found the resonant point.

A rattle in the low range, roughly 100-400 Hz on a phone, often means debris on the mesh, which the dust cleaner sweep and a soft brush may fix. A buzz that appears across many frequencies, or distortion that worsens over time, points at the driver itself.

Which waveform should I use?

Sine is the right default: it is a pure tone with no overtones, so anything extra you hear, buzz, crackle, rattle, is coming from the speaker rather than the signal. That purity is what makes sine tones the standard for audio testing.

Square, triangle, and sawtooth waves add harmonics above the base frequency, which makes them sound brighter and harsher. They are useful for hearing how a speaker handles harmonically rich content, and square waves make low frequencies audible on small speakers that cannot reproduce the fundamental. Keep the volume lower with these; harmonically rich waves sound louder at the same setting.

Safe listening with test tones

Steady tones are more fatiguing than music at the same volume, because the energy sits at one frequency instead of moving around. Start every session at low volume and raise it only as needed, especially between 2 kHz and 5 kHz where human hearing is most sensitive.

Take the tone out of your ears before changing anything drastic: if you are testing headphones, set the volume with them off your head first. And there is no reason to run any test tone at maximum volume; every diagnostic described here works at moderate levels.

Related tools

Speaker Sound Test

Check your speaker with simple left/right test tones.

Water Eject

Play a low-frequency sweep for trapped speaker moisture.

Phone Speaker Cleaner

Try the dust cleaner mode for muffled speaker sound.

Questions

What frequency range can humans hear?+

Roughly 20 Hz to 20 kHz for young, healthy ears. The top end falls with age; many adults hear little above 15 kHz, which you can check gently with the high presets at moderate volume. Phone speakers themselves typically roll off well before both extremes.

Why can't I hear the 20 Hz tone on my phone?+

Phone speakers physically cannot reproduce 20 Hz; most produce little below 150-200 Hz. If you hear something at very low settings it is usually harmonic distortion rather than the fundamental. To hear true sub-bass, run the tone through headphones or a subwoofer at low volume.

Can I use the tone generator to test my hearing?+

As a rough curiosity check, yes: step through the high presets at a fixed moderate volume and note where tones become inaudible. It is not a medical test, since speaker limits and room noise skew results. For real concerns about hearing, see an audiologist for a calibrated audiogram.

Does the tone generator work for tuning instruments?+

Yes. Set it to 440 Hz for concert-pitch A and tune by ear against the sine tone, or pick any reference pitch you need. A dedicated tuner app is more convenient for full tuning sessions, but a steady reference tone is exactly what tuning forks provided for centuries.

Why does the same volume sound louder at some frequencies?+

Human hearing is not equally sensitive across the range: we hear midrange frequencies, roughly 1-5 kHz, far more easily than deep bass or very high treble at the same physical level. That is normal and expected, not a fault in your speaker or the tool.