Sound only in your left (or right) ear is usually a settings problem or a loose plug, not broken headphones. Work through these fixes in order; most people are sorted by step 1 or 2. Each step says how to check it on Windows 11 and Windows 10.

Quick check: headphones or PC?

Plug the headphones into your phone and play something. Still one ear? The headphones or their cable are faulty, so skip to step 9. Both ears work? The problem is on the PC side. Keep going.

1. Check the left/right balance

Windows 11:

  1. Open Settings → System → Sound and click your headphones under Output.
  2. Under Output settings, check the Left channel and Right channel sliders are equal.

Windows 10: Control Panel → Sound → Playback → your headphones → Properties → Levels → Balance, and set L and R equal.

Balance gets changed by accident more than you’d think, sometimes by audio software or a driver update.

2. Push the plug all the way in

A 3.5 mm plug that’s half inserted often plays in one ear only, or plays music without vocals. Push it firmly until it clicks, and try the other jack if your PC has front and back ports. Lint in the jack can stop a plug seating. A careful blast of compressed air helps.

3. Remove adapters

If you’re using a USB-C to 3.5 mm adapter, a splitter, or a 4-pole to 3-pole adapter, take it out and plug in directly. Mismatched adapters are a common cause of one-sided or vocal-less sound.

4. Turn Mono audio on (or off)

Windows 11: Settings → Accessibility → Audio → Mono audio. Windows 10: Settings → Ease of Access → Audio → Turn on mono audio.

Turning it on sends everything to both ears, which fixes videos and games that pan sounds hard to one side. If it’s already on and you hear odd results, try it off.

5. Turn off spatial sound and audio enhancements

In your headphones’ Output settings, set Spatial sound to Off and switch off Audio enhancements. Some enhancement software (and some “virtual surround” modes) mishandles certain headphones and can swallow one channel.

6. Check the app, not just Windows

If it only happens in one app, look in that app’s own audio settings for balance, mono or surround options. Games in particular often have a “speaker setup” option. Set it to Headphones or Stereo.

7. Bluetooth: reconnect and choose the Stereo output

  • Choose the Headphones / Stereo output, not “Headset” or “Hands-Free”.
  • For true-wireless earbuds and AirPods, put both buds back in the case for a few seconds, then take them out together so they resync.
  • Still one-sided? Remove the device in Settings → Bluetooth & devices and pair again.

8. Update or reinstall the audio driver

Open Device Manager → Sound, video and game controllers, right-click your audio device and choose Update driver. Or choose Uninstall device and restart, and Windows reinstalls it. Your PC maker’s support page often has a newer driver than Windows Update.

Sound in one laptop speaker

The same balance setting (step 1) applies to laptop speakers. If one built-in speaker is silent even with balance centred and Mono audio on, play a left/right channel test video. If one side never plays, the speaker or its cable is faulty, which is a repair job.

9. When it’s the headphones

If the headphones are one-sided on every device, wiggle the cable near the plug and near the earcup while music plays. Crackling or sound returning means a broken wire. Wired headphones with a detachable cable can be fixed with a new cable. Otherwise it’s a warranty or replacement job.

Sharing one pair of earbuds, one bud each? Turn on Mono audio so neither of you misses dialogue or music that’s mixed to one side. Better still, give each person their own pair. Here’s how to use two headphones on one PC.