Quick answer
First check the mic icon in the meeting bar isn't crossed out (unmute it) and there's no physical mute switch on your headset. Then open Teams → Settings → Devices and make sure the right microphone and speaker are selected, and run a test call. On Windows, confirm microphone access is on for apps under Privacy settings.
WHY IT HAPPENS
Rarely the mic — usually a setting.
When people can't hear you in Teams, the cause is almost never a faulty microphone. Far more often you're simply muted, Teams is pointed at the wrong device (the laptop's built-in mic instead of your headset, say), or Windows is blocking apps from using the microphone. A recently plugged-in headset, a Windows update that reset your privacy permissions, or another app holding the mic can all cause it too. The steps below start with the fastest, most common fixes and only move to hardware and deeper resets if those don't work.
THE FIX
Work through these in order.
- Check you're not mutedLook at the mic icon in the meeting controls — if it has a line through it, click it to unmute. Then check your headset or external mic for a physical mute button or switch, which is easy to knock on by accident.
- Turn on microphone permissions in WindowsGo to Settings → Privacy & security → Microphone. Switch on Microphone access and Let apps access your microphone, and make sure Microsoft Teams is allowed. If it was already on, toggle it off and back on, then restart Teams — a Windows update sometimes resets this.
- Pick the right device in Teams settingsIn Teams, click the ... menu → Settings → Devices. Under Audio devices, set the Microphone and Speaker to the ones you're actually using (your headset, not "Default"). Choosing the wrong device is the single most common cause.
- Run a test callStill in Settings → Devices, click Make a test call. The bot asks you to record a short message and plays it back, confirming both mic and speakers work. If you hear nothing, switch to a different device on this screen and test again.
- Reconnect the headset or USB deviceIf you're using a USB or Bluetooth headset, unplug and replug it (or re-pair Bluetooth), then re-select it in Teams. A loose or half-connected device often shows up but carries no sound. Try a different USB port if you can.
- Free the mic from exclusive modeWindows lets a single app "take over" a microphone and lock others out. In Settings → System → Sound, open your microphone's properties and, under the advanced options, untick allow applications to take exclusive control of this device. Then restart Teams.
- Clear the Teams cache or restart audioIf audio is still glitchy, clear the Teams cache so it rebuilds cleanly — see our guide on clearing the Teams cache. A full restart of the PC also resets the Windows audio service and clears any app still hogging the microphone.
Tried everything and still silent? If the mic works in the Windows Sound test but not in Teams — or the fault follows one particular person or device around the office — it can point to an audio driver, a group policy, or a headset that needs replacing. That's the point to hand it to your IT provider rather than losing time before each call.
