Put on your headphones or sit between stereo speakers, then route a clean browser tone to LEFT, RIGHT or BOTH / CENTER. This is a basic stereo direction and routing check: confirm the sound comes from the expected side before using the frequency controls for practical playback comparisons. It is not a surround, binaural or HRTF spatial-audio test.
Start with your device volume low. This tool is for equipment checks, not a hearing test. Stop immediately if a tone is uncomfortable.
Web Audio generator
Left, center and right headphone / speaker test
TONE STOPPED
440Hz
100 Hz1 kHz8 kHz
What this headphone test checks
The left, right and center controls send the same sine-wave reference to a selected stereo channel. They can reveal swapped routing, a silent side, a strong balance mismatch or an intermittent connection. The frequency control can help you reproduce an obvious rattle or dropout at the same setting.
The page does not measure sound-pressure level, frequency response, distortion, hearing thresholds, surround position or physical driver health. A PASS means the expected reference signal played and you heard the intended routing.
How to run a repeatable low-volume test
Disconnect from calls and close other audio apps.
Set operating-system balance to equal left and right, disable spatial effects, and lower the master volume.
Wear the headphones on the marked sides or sit centered between speakers.
Select BOTH / CENTER at 440 Hz, start the tone, then raise volume only to a comfortable level.
Select LEFT ONLY and RIGHT ONLY without changing volume. Note the side, apparent level and any crackle.
Return to BOTH / CENTER before trying 250 Hz, 1 kHz and 4 kHz. Move gradually; do not chase inaudible tones with more volume.
Repeat any anomaly after reseating the plug or reconnecting Bluetooth.
Cross-check with another output, cable or device before assigning the fault to one component.
Worked result patterns and next checks
Observed pattern
What it can mean
Next check
LEFT plays in the right ear and RIGHT plays in the left
Reversed earcups, cable orientation or software routing
Check labels and detachable-cable orientation, then repeat on a second device.
One side is silent at every frequency
Loose plug, damaged cable, disabled channel or failed driver/output
Reseat connectors, inspect balance, swap outputs and test a known-good headset.
BOTH / CENTER pulls consistently to one side
Balance setting, fit/position difference, room effect or channel-level mismatch
Center your position, swap sides or outputs, then compare again at the same volume.
A buzz repeats only near one frequency
Possible enclosure rattle, loose object, room resonance or source-chain distortion
Lower volume, change physical position and repeat with another source; do not label it a failed driver from this test alone.
Symptom-led troubleshooting
Sound appears on both sides during LEFT ONLY
Disable mono audio, surround virtualization and channel-mixing enhancements. If the result persists, try another browser or wired output.
Bluetooth crackles or drops out
Move closer, remove competing wireless devices, verify the headset is using its stereo profile rather than a call profile, and compare with a cable if supported.
The tone starts but is not audible
Check the active output device, browser tab mute state and operating-system volume. Stop the tone before changing connections, then start it again.
Using frequency comparisons responsibly
Begin at 440 Hz, then compare moderate presets at exactly the same device volume. Use the slider to reproduce a specific rattle or dropout, not to create a hearing threshold.
Natural headphone/speaker response, equalization and room acoustics make some tones seem louder. At the low end, small speakers may reproduce little acoustic output; at the high end, listener sensitivity and codecs matter.
Never raise the volume sharply to make a high or low tone audible. Stop immediately if a tone is uncomfortable.
Browser, acoustic and hearing limits
Web Audio sets a digital sine-wave frequency; it does not verify the physical output.
The displayed −32 dB value is generator gain relative to full scale, not measured dB SPL.
Operating-system processing, DACs, amplifiers, codecs and device volume remain outside this page.
Room placement and reflections can dominate speaker comparisons.
Stereo left/center/right is not binaural, surround or HRTF spatial positioning.
No result on this page diagnoses hearing ability or certifies manufacturer specifications.
Privacy and data handling
The tone is generated in the browser and this diagnostic does not request microphone access. Ordinary hosting, consented analytics and advertising requests are described in the Privacy Policy. The Methodology explains how browser diagnostics and limitations are reviewed.
Headphone left/right and frequency test FAQ
What should I do if LEFT plays in the right ear?
Confirm the headphones are worn on the correct sides, then check detachable cable orientation, adapters, operating-system balance and channel-routing software. Repeat the test with another device before concluding that the earcup is wired incorrectly.
Why does BOTH / CENTER sound closer to one side?
Check the operating-system balance control, reseat the plug and swap the headphones or speakers to another output. Room position and unequal earcup fit can also shift the apparent center, so this result is a troubleshooting clue rather than a calibrated channel measurement.
Why is one test frequency quieter than another?
Headphone or speaker response, equalization, codecs, room reflections and human hearing sensitivity all vary by frequency. Compare repeatable changes at the same volume; this browser tone is not a calibrated frequency-response measurement.
Does no sound at 8 kHz prove that my headphones are broken?
No. High-frequency audibility varies with the listener, playback hardware, volume, codecs and browser or operating-system processing. Cross-check on another device and use measurement equipment or a hearing professional for a definitive conclusion.
Why does the browser require a click before audio starts?
Modern browsers usually block autoplay audio until the user interacts with the page. Pressing Start Tone provides that required interaction and creates the Web Audio signal.
Can I use this page to diagnose hearing loss?
No. This is an equipment and stereo-routing check, not a hearing test. Use a qualified hearing professional and clinical equipment for hearing concerns.
