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Left Right Sound Test

A left right test plays a sound only in the left channel, then only in the right, then in both. If each sound comes from the matching side, your headphones or speakers are connected correctly. If they are swapped, turn the headphones around, check the plug or turn off mono audio.

Before you start

Turn your volume down before you start. Stop if anything is uncomfortable. Long exposure to loud or high-pitched sound can damage hearing.

These tests need JavaScript to make sound. The explanations below work without it.

Sound starts only when you press a button, at a low level with a soft fade-in. The level is capped in the code. Esc or the space bar stops it. On iPhone, turn off silent mode or web sound may stay muted. This is not a medical hearing test.

Left / right test

Balance test

How to do it

  1. Turn the volume down.
  2. Press L and listen: the sound should be only in your left ear.
  3. Press R: the sound should be only in your right ear.
  4. Press C: the sound should seem to come from the middle.
  5. Answer the question to get a result and tips.

If left and right are wrong

  • Swapped: check the L/R marks; on speakers, swap the two cables at the amplifier or the computer.
  • Both sides at once: mono audio is probably on. On iPhone it is under Accessibility, Audio & Visual. On Android, Windows and Mac it is in the accessibility or sound settings.
  • One side silent: re-insert the plug fully, try another device, or reconnect Bluetooth.
  • Crackles on one side: often a worn cable or a dirty plug.

Frequently asked questions

How do I know if my headphones are left and right?

Press L in the left/right test. If you hear it in your left ear, the left channel is correct. Then press R. Most headphones also print L and R on the band, the ear cups or the stems.

Why do I hear the left sound in both ears?

Mono audio is probably switched on, which mixes both channels into each ear. Turn it off in your phone or computer accessibility settings and test again. Some cheap adapters and Bluetooth modes are mono too.

Why is the center sound not in the middle?

If the center sound leans to one side, one side is quieter. Use the balance test on this page to measure the difference, then check the balance setting, clean the earbuds and try another device.

Does the test work on speakers?

Yes. Sit in front of the speakers, between them. The left sound should come only from the left speaker and the right sound only from the right speaker. Center should seem to come from between them.

Can a game or app swap left and right?

Yes. Some games, video calls and audio apps have their own channel or spatial settings. If this test is correct but one app is wrong, check that app’s audio settings.

Last updated: October 13, 2026

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