Audio Frequency Test

What is this tool?

The Audio Frequency Test generates a single sine tone anywhere from 20 Hz to 20,000 Hz and lets you move through that range in several ways: a logarithmic slider, band presets, an automatic sweep, a nineteen-step stepper, and an A/B pair you can flip between.

The logarithmic mapping matters. Hearing works in ratios, not in hertz, so a linear slider would waste most of its travel above 5 kHz. Here the whole slider is usable, and the band buttons — FULL 20 Hz–20 kHz, LOW 20–250 Hz, MID 250 Hz–2 kHz, HIGH 2–20 kHz — narrow it further when you want fine control in one region.

It is a signal generator with listening exercises attached, not a hearing test and not a measurement instrument. Every conclusion comes from what you report hearing; the page's own “WHAT THIS TOOL CAN AND CANNOT MEASURE” section draws the same line.

How to use it

1. Turn the volume down before you startHigh frequencies at high volume are unpleasant and, sustained, are a genuine hearing risk. Start near silence and raise the level only until the tone is comfortably audible.
2. Choose a band, then tunePick FULL, LOW, MID or HIGH depending on what you are investigating, then use the slider or type an exact frequency. The readout always shows the frequency actually being generated.
3. Run a sweepSweeps move continuously in one of three directions — low to high, high to low, or ping-pong — and can be paused and resumed. A sweep is the fastest way to find a rattle or a resonance, because the problem appears at a specific frequency as the tone passes through it.
4. Step through the 19-step stepperThe stepper walks a fixed nineteen-frequency ladder across the range so you compare the same points every time. It is the repeatable version of a sweep, and it is what to use when comparing two sets of headphones.
5. Compare two frequencies with A/BSet an A frequency and a B frequency and switch between them instantly. Immediate switching is far more revealing than playing one, stopping, and playing the other from memory.
6. Build your own sequence, or run the guided testsThe sequence builder saves a custom list of frequencies in your browser's local storage for reuse. The guided path is a seven-step quick test and a seven-phase full diagnostic; session history is also kept locally.

What the results mean

The frequency you cannot hear any more

As you sweep upward there is a point where the tone stops being audible. That point moves down with age for everyone — it is normal. Because the number depends on your volume, your headphones and your room, treat it as a rough personal observation and not as an audiogram.

Frequencies where nothing comes out

A band that goes silent while its neighbours are fine points at the playback chain: a driver that does not reach that low, a speaker that cannot go that high, or an equaliser cutting that region. Small speakers genuinely have nothing below roughly 100 Hz.

Rattles, buzzes and resonances

A buzz that appears at one frequency and disappears a few hertz either side is mechanical: a panel, a port, a loose grille or an object on the desk vibrating in sympathy. It is a property of the enclosure or the room, not of the tone.

Distortion instead of a clean tone

A pure sine should sound smooth. If it sounds gritty, doubled or harsh, something in the chain is being pushed past its limit — usually volume. Lower the level; if it cleans up, the tone was fine and the amplifier or driver was not.

Left and right not matching

Sweep with both ears covered, then one at a time. A frequency present on one side and weak on the other is a channel difference, and the Speaker Balance Test and Left Right Audio Test are the tools for pinning it down.

What it can detect

• The upper limit of what you can hear on this device at this volume
• Frequency ranges your speakers or headphones do not reproduce
• Mechanical rattles and resonances that appear only at specific frequencies
• Distortion that appears as volume rises
• Left/right differences that only show up in part of the range

Limits worth knowing

A browser can only report what the platform gives it. These are the honest boundaries of this page, so a result is never read as more than it is.

• This is not a hearing test. There is no calibrated output level, so the tool cannot say how loud a tone is at your ear, and cannot produce a threshold in dB HL. If you are worried about your hearing, an audiologist with calibrated equipment is the answer.
• The tone leaves as digital samples and the page never hears it back — there is no microphone in this tool. It therefore cannot measure your speaker's frequency response, its distortion, or its output level. The page's own “WHAT THIS TOOL CAN AND CANNOT MEASURE” section says exactly this.
• The generator is accurate to what the Web Audio API is asked to produce; what your ears receive has passed through your operating system's mixer, any equaliser or spatial-audio processing, your DAC, your amplifier and your drivers. A result is about that whole chain.
• Bluetooth headphones re-encode the signal. High frequencies and very quiet tones are the first things a lossy codec spends its budget on, so a wired connection is the honest way to test the extremes of the range.
• Sustained loud tones, especially above about 8 kHz, are genuinely unpleasant and can damage hearing. Keep the volume low; this is a real limit on how the tool should be used, not a formality.

Tips

• Use the 19-step stepper rather than a freehand sweep when you are comparing two devices — identical frequencies at identical volume is the only fair comparison.
• If a rattle appears, stop the sweep on it and move things on the desk one at a time. Half of all mysterious buzzes are an object in the room, not the speaker.
• Save a custom sequence of the frequencies that matter to you; the builder keeps it in local storage so the same ladder is one click away next time.

Troubleshooting

Related documentation

• AudioAudio Bass Test20 Hz to 250 Hz tones for sub-bass reach, rattle hunting and distortion checks.
• AudioHeadphone TestEars, balance, separation, bass and treble checks built for headphones and earbuds.
• AudioSpeaker TestLeft, right, stereo, bass, treble and sweep tones for laptop or desktop speakers.
• AudioSpeaker Balance TestA nine-position balance stepper from full left to full right, with separation checks.
• AudioStereo TestChannel isolation, balance, separation and phase checks for any stereo setup.