How to run the left right audio test
- Turn the volume down, then put your headphones on with the L side on your left ear. For speakers, sit in the middle, facing them.
- Press Left. You should hear short bursts of sound in your left ear only, with nothing on the right.
- Press Right. Now the sound should be in your right ear only.
- Press Both. The sound should seem to come from the center of your head (or from between the speakers).
- Prefer hands-free? Press Auto test L → R: it plays left, right, left, right, then both, and lights up the side you should be hearing.
The noise bursts are easier to place than a pure tone, which is why they are the default. Switch to Beep tone if you prefer a cleaner sound.
What your results mean
| What you hear | Likely cause | What to do |
|---|---|---|
| Left plays on the right, right on the left | Headphones worn backwards, or channels swapped | Check the L/R marks; try another cable or adapter |
| Both buttons play in both ears | Mono Audio is on | Turn off Mono Audio (see settings below) |
| One side is quiet or silent | Balance shifted, blocked mesh, or a faulty side | Reset balance to the middle; clean the ear tip; test with another device |
| Sound cuts in and out on one side | Loose cable or plug, or weak Bluetooth link | Wiggle the cable gently while testing; move closer to the phone |
| Everything sounds right | Your channels are fine | Nothing to fix |
Left right headphone test: earbuds, AirPods and wired headphones
For a left right headphone test, the most common problem is simply wearing them the wrong way round. Over-ear headphones usually have a small L and R inside the headband or ear cup; earbuds and AirPods have it printed on the stem or under the tip.
If one earbud stays silent in this test, check whether it is connected at all: many true wireless earbuds can drop one side while the other keeps playing. Put both back in the case for a few seconds, take them out again and rerun the test. If one side is still silent, try resetting the earbuds following the manufacturer's instructions.
Stereo test for speakers: sweep and phase
The stereo sweep moves the sound smoothly from the left speaker to the right and back. A good stereo setup gives a continuous movement with no "hole" in the middle and no jump between speakers. If the sound jumps, check that your speakers are the same distance from you and that the balance is centered.
The phase test checks the wiring. Press In phase, then Out of phase. In phase should sound solid and focused between the speakers; out of phase should sound wide, hollow and with less bass. If it's the other way round, the + and − wires on one speaker are probably swapped. This left right stereo test is the quickest way to catch that without opening anything up.
How to fix left/right balance and mono audio settings
- iPhone: Settings → Accessibility → Audio & Visual. Set the Balance slider to the middle and turn Mono Audio off.
- Android: Settings → Accessibility → look for Audio adjustment or Hearing enhancements (the name depends on the brand). Center the left/right balance and turn off Mono audio.
- Windows 11: Settings → System → Sound → choose your output device → set Left and Right channel volume to the same level. Mono audio is under Settings → Accessibility → Audio.
- Mac: System Settings → Sound → Output → set Balance to the middle. Mono audio is under System Settings → Accessibility → Audio.
How we tested this tool
We checked the left right audio test in Google Chrome on Windows and in a mobile-size browser view. To confirm the channel routing itself, we rendered the signal offline in the browser and measured each output channel: a left-only signal produced full level on the left channel and zero on the right. Tried it on your own headphones or speakers? Let us know and we'll add your results here.
Frequently asked questions
Why do I hear the left sound in my right ear?
Most often the headphones are on the wrong way round: check the small L and R marks on each side. If they are on correctly, the channels are swapped somewhere else, for example in a cable, an adapter, or a sound setting that reverses channels.
Why does the sound come from both sides when I press Left?
Mono Audio is probably turned on. It mixes left and right into both ears. Turn it off in your device's accessibility or sound settings, then run the left right audio test again.
One side is quieter than the other. Is my headphone broken?
Check the balance setting first: it may be shifted to one side. Then clean the ear tip or mesh on the quiet side, since earwax often blocks it. If both are fine and the side is still quiet, the driver or cable may be damaged.
What does the stereo phase test show?
It checks whether both speakers push air in the same direction. "In phase" should sound solid and centered. If "Out of phase" sounds more solid than "In phase", one speaker's + and − wires are probably swapped.
Does this work with Bluetooth earbuds and AirPods?
Yes. Connect them as normal and run the test. Bluetooth adds a short delay, so the sound may start a fraction of a second after you press a button. That is normal.