Possible reasons:
a microphone is not defined in the browser,
a microphone is not connected to a computer,
a microphone is missing or malfunctioning,
a microphone is occupied by another application.
Use the lonks below to test your microphone and webcam:
Microphone: https://www.onlinemictest.com/
If it does not help, check if the microphone is allowed in the browser. In the address bar on the left, click the Lock icon to display device permissions.
Make sure Camera and Microphone are set to Allow
Click the Lock icon to close the pop up
Refresh your browser window
Allow Examus website access your camera and microphone.
Examine if a correct device is selected in browser settings.
This is the settings page in Chrome: chrome://settings/content/microphone
Examine if the correct microphone is selected in the Sounds menu. It is important to see a signal indicator next to the microphone name. If the indicator exists and captures sounds, the microphone works properly.
If you are using an internet security suite it might be blocking access to your webcam. To allow Examus to access your webcam, you will need to disable the security suite function that is blocking access to your webcam and microphone. We have listed some of the most common internet security suites below:
AVG
Avast!
Kaspersky
eset
The audio troubleshooter might be able to fix audio problems automatically. To run the troubleshooter:
In the search box on the taskbar, type audio troubleshooter, select Fix and find problems with playing sound from the results, then select Next.
Select the device you want to troubleshoot and then continue through the troubleshooter.
You can also launch the troubleshooter from audio Settings: Select Start >> Settings >> System >> Sound >> Troubleshoot.