Headphone Test — Drivers & Imaging

A headphone test checks four things about a pair of headphones: that each ear produces sound, that the two drivers match, that stereo timing cues place correctly, and that the drivers keep working over time. Everything runs in your browser with the Web Audio API; nothing is uploaded, and no sound plays until you press a button.

How to use it

1. Set a low volume first. Each signal has a fixed digital gain, but your system volume sets the acoustic level. Start low, and do not turn the volume up to force a faint signal into audibility.
2. Confirm channel identity. Pick Left, then press Play isolation tone. An 880 Hz sine is hard-panned to that ear for 2 seconds, so the opposite ear should hear silence. Repeat on Right.
3. Compare the drivers. Leave Alternate L/R on and press Play pink noise. Spectrally even pink noise swaps ears every 1.2 seconds with a 20 ms pan ramp, so the swap is smooth rather than clicky.
4. Freeze one side for a longer listen. Press Left or Right on the matching panel to hold the noise in one ear; press Alternate L/R to resume.
5. Sweep the ITD demo. Press Play ITD demo and move the delay slider from 0 to 0.7 ms in 0.05 ms steps. The same 500 Hz tone reaches both ears; only the timing differs.
6. Run burn-in as a soak test only. Choose 1, 5, 15, or 30 minutes and press Start burn-in. Centred pink noise plays at reduced gain with an mm:ss countdown and stops itself at zero.

What each section checks

The page runs four independent checks, and each one isolates a different failure mode.

Channel identification and wiring

The isolation tone is a 2 second, 880 Hz sine at 0.3 gain, panned fully to one side. A correct setup gives sound in the named ear and nothing in the other; if the tone labelled Left arrives on the right, a cable, an adapter, or an operating-system channel setting is reversed. Bleed in the opposite ear on open-back models is acoustic, not electrical: sound travels around your head.

Polarity, rattle and buzz

A polarity swap between the two channels is much harder to hear on headphones than on speakers, because the two channels never mix in the air. A 180 degree offset smears the interaural phase of centred content instead of cancelling it, and becomes obvious only when the channels are summed to mono somewhere else in the chain.

Buzz and rattle detection is easier. Pink noise excites every octave at once, so a loose driver or a vibrating housing buzzes on every alternation. Swap the cups between ears to separate a driver fault from a cable fault: a buzz that stays with the same cup points at the headphone.

Driver matching with pink noise

Pink noise carries equal energy per octave, which is what makes it a useful matching signal: the two drivers should deliver the same bass weight and treble texture. Alternate L/R swaps the noise every 1.2 seconds at 0.25 gain, so a level or tone difference repeats on every swap. A difference you hear only at the instant of the swap is usually a level mismatch; a difference that persists within one side is usually a driver or fit problem.

ITD localisation demo

The demo feeds one 500 Hz sine into two DelayNodes, leaves the leading ear at 0 ms, and delays the other ear from 0 to 0.7 ms. Human interaural time differences top out near 0.65 ms, so the slider can push the image slightly past the natural limit. Level is identical in both ears, so you hear pure timing with no level cue to help.

Delay on the lagging ear	Phase offset at 500 Hz	What you should hear
0 ms	0°	Dead centre, inside your head
0.1 ms	18°	Clearly off-centre toward the leading ear
0.25 ms	45°	Well to the leading side
0.5 ms	90°	Near the edge of the image
0.65 ms	117°	At the natural ITD limit
0.7 ms	126°	Beyond the typical human range

Time-boxed burn-in

Burn-in has no proven benefit for headphone sound quality, and the page says so next to the control. The option exists so you can confirm a pair keeps working over a longer session. The noise is centred, plays at 0.2 gain, and stops at 00:00.

Accuracy, limits and troubleshooting

• Levels are dBFS, not dB SPL. The page reports digital level relative to full scale. It has no microphone and no calibration, so it cannot tell you how loud your headphones are in the room.
• Operating-system processing can defeat the test. Mono audio settings fold both channels into both ears, and head-tracking spatial audio re-renders stereo, which smears the ITD demo. Disable both before testing.
• Hard pan is exact in software. If the opposite ear hears the isolation tone, suspect a reversed cable, a mono setting, or acoustic bleed on open-back models rather than the page.
• Bluetooth latency does not break the ITD demo. A2DP sends both channels through one codec stream, so the relative delay survives. Head-tracking features and separate per-ear processing in some true wireless sets can still disturb it.
• Delay resolution is fine. At 48 kHz a 0.05 ms step is about 2.4 samples, and the DelayNode interpolates between them; at 44.1 kHz it is about 2.2 samples.
• The AudioWorklet needs a secure context. Pink noise is generated in an AudioWorklet, which browsers load only on HTTPS pages. If noise fails while the tone works, check the page scheme and any extension that blocks workers.
• This page cannot measure frequency response, distortion, or isolation. It is a listening and routing check; use the oscilloscope, spectrum analyser, and THD test for measurement work.
• Keep sessions short and levels modest. In-ear models sit close to the eardrum, and a faint signal caused by a poor seal can tempt you to raise the volume. If you are concerned about your hearing, see an audiologist.

Related tools

• Headphone Burn-In Test — Time-boxed soak runs with a countdown and a stop control.
• Speaker Test — The same channel, balance, and polarity checks through loudspeakers.
• Sound Localization Test — A scored ITD and ILD test that measures your placement accuracy.

Aliases covered on this page: headphone test, left right headphone test, headphone channel test, headphone driver matching, and headphone burn in test.