Headphone Test
Put on your headphones or earbuds, set the volume low and work through the tests: left and right channels, a full 20 Hz to 20 kHz frequency sweep, bass and treble tones, phase polarity and a binaural sound that circles around your head.
Turn your device volume down before you start, then raise it slowly.
Left must come only from the left ear (L), right only from the right ear (R) and center from both equally, as if inside your head.
Bass
Treble
Tap a tone to play it, tap again to stop. Low bass needs a good seal; very high tones may be inaudible to adult ears even when the headphones play them.
If the out-of-phase sound feels more centred and fuller than the in-phase one, one driver in your headphones is wired with reversed polarity.
Close your eyes and follow the sound. Works with headphones only. Uses the browser's HRTF (head-related transfer function) panner.
How to use the Headphone Test
- Turn your volume down to about a quarter, put on your headphones and use the Volume slider to adjust.
- Left / Right tab: press Play left, Play right and Play center. Each sound must come only from the matching side.
- Sweep tab: press Start sweep and listen as the tone rises from 20 Hz to 20 kHz; press Mark when it fades out.
- Bass & Treble tab: play individual tones to find the lowest and highest frequencies your headphones reproduce.
- Phase and 3D tabs: compare in-phase and out-of-phase sound, then play the 3D sound and follow it around your head.
What each headphone test checks
| Test | What you should hear | What a problem sounds like |
|---|---|---|
| Left / Right | Sound only in the matching ear; center sounds inside your head | Sound in the wrong ear (swapped channels), one side silent or quieter (balance, damaged driver or cable) |
| Frequency sweep | A smooth tone rising from a low hum to a thin whistle | Rattles, buzzing or sudden drops at certain frequencies, or a tone that jumps between ears |
| Bass tones | Clean, steady low notes, felt as much as heard at 20 to 40 Hz | Distortion, flapping or crackling, which means the volume is too high or the driver is damaged |
| Treble tones | Clear high pitches up to the limit of your hearing | Hiss or harshness, or nothing above 10 to 12 kHz in both ears |
| Phase | In phase: solid and centred. Out of phase: wide, hollow, thin bass | The two sound the other way round: one driver has reversed polarity |
| 3D sound | A sound circling around your head, including behind you | Sound only moving left to right, which is normal for some listeners and for speakers |
How the frequency sweep works
The sweep is a pure sine wave that rises logarithmically from 20 Hz to 20,000 Hz, so each octave takes the same time. The frequency at time t is f(t) = 20 × 1000t / T Hz, where T is the sweep length. With a 20 second sweep the tone passes 100 Hz after about 4.7 seconds, 1 kHz after 11.3 seconds and 10 kHz after 18 seconds. Press Mark when the tone disappears to record your upper limit.
Typical upper hearing limits by age (approximate, they vary a lot between people):
| Age | Usually audible up to |
|---|---|
| Under 20 | 17 to 20 kHz |
| 20 to 30 | 15 to 17 kHz |
| 30 to 50 | 12 to 15 kHz |
| Over 50 | 8 to 12 kHz |
This is not a medical hearing test. If you notice a sudden change in your hearing, see a doctor or audiologist.
Tips for accurate results
- Turn off any equaliser, bass boost, spatial audio or "3D" effect in your phone, computer or headphone app while testing.
- Check that your system sound is not set to mono, and that the left/right balance slider is in the centre.
- Use a quiet room and moderate volume; loud background noise hides bass and quiet high tones.
- Test each ear separately with the sweep's Ear option to compare left and right.
Frequently asked questions
How do I know if my headphones are left and right correctly?
Press Play left: the sound must come only from the left ear cup or earbud, marked L. Then press Play right. If the sides are swapped, check that you are wearing them the right way round; if they are still swapped, the cable, adapter or audio settings (such as a mono or balance option) may be the cause. If one side is silent, try another device to see whether the headphone or the source is faulty.
What frequency range should headphones play?
Human hearing covers roughly 20 Hz to 20 kHz, and most headphones are rated for that range. In practice many earbuds roll off below 40 to 50 Hz, and adults often cannot hear above 14 to 17 kHz because high frequency hearing declines with age. Not hearing the top of the sweep is usually your ears, not the headphones.
What does the phase test show?
In phase, both ears get identical sound and it seems to come from the centre of your head. Out of phase, one channel is inverted, so the sound feels spread out, hollow or hard to place, with weaker bass. If the out-of-phase sample sounds more natural and centred than the in-phase one, one speaker in your headphones is wired with reversed polarity.
How does the 3D binaural sound work?
The browser's HRTF panner filters the sound the way your head and ears do for a sound coming from a particular direction, adding tiny timing and tone differences between the ears. With headphones the sound appears to move around you. It only works properly with headphones or earbuds, not speakers, and the effect is stronger for some listeners than others.
Why can't I hear the lowest bass tones?
Tones at 20 to 30 Hz are felt more than heard and need a good seal. Earbuds that do not seal well in the ear, open-back headphones and laptop speakers lose a lot of deep bass. Try different ear tips, press the ear cups gently against your head, and raise the volume slightly for the lowest tones only.
Is it safe to play these test tones?
Yes at moderate volume. Start with your device volume low and raise it slowly; high frequency tones can sound quiet and then become uncomfortable. Do not listen to loud test tones for long periods, and stop if anything feels painful or causes ringing in your ears.
Does the test work with Bluetooth headphones?
Yes. Bluetooth adds some delay, which does not matter for these tests. Some Bluetooth codecs cut frequencies above about 16 to 20 kHz, so the very top of the sweep may disappear earlier than on wired headphones.