Separate permission, input-selection and real signal issues in a few minutes.
First identify where the problem is
A microphone that is missing entirely is different from one that appears but produces no sound. The first usually points to browser or operating-system permissions; the second is more likely to involve input level, a physical mute switch or the wrong microphone. After permission is granted, DeviceDoctor shows only the signal level reaching the browser and does not record the audio.
- Check microphone permission in the browser address bar.
- Select the correct input device in your operating-system sound settings.
- Check the headset mute switch and cable.
What to do when there is no signal
If the microphone name is correct but the level does not move, another application may be using the device. Close video-call applications and run the test again. Reconnecting Bluetooth headsets can restore the correct input profile. Increase operating-system input gain if the level is very low, but avoid excessive gain when it also raises noise.
The test confirms the signal reaching the browser; it is not a calibrated decibel or professional audio-quality measurement. Finish by making a short call recording to verify what the other person receives.