If you are not hearing sound in CertMaster videos, try the following troubleshooting steps:
Check Your Audio Configuration
Some CertMaster videos only support mono and stereo audio configurations. If you are using surround sound (3.1, 5.1, 7.1, etc.), switch your audio settings to stereo or mono.
Some browsers, particularly Firefox, may have trouble playing videos encoded with mono audio. If the issue persists, try using Chrome or Edge.
Check Whether the Browser Tab Is Muted
Make sure the browser tab is not muted and that websites are permitted to play audio.
Check the Windows Volume Mixer
Right-click the volume icon in the system tray and open the Volume Mixer. Verify that no applications are muted.
Verify Speaker Settings
Ensure your speakers or headphones are connected properly, powered on, and the volume is turned up.
Restart Windows Audio Playback
In some cases, opening the Windows Movies & TV app and then reopening your browser may restore audio playback.