This issue can be caused by incompatibility between the video file recorded by the Xiaomi Outdoor Camera CW100 Dual and the media player on your computer. Try using a different media player, such as VLC Media Player.
Below is more information regarding the issue with the camera:
The default media player on some computers can not support the audio codec used in the recorded video;
VLC Media Player and other third-party players offer broader codec support and are recommended for playback;
Ensure that the video file was copied correctly from the memory card to the computer;
If the problem persists, check if the computer's audio output is functioning normally and that the volume is not muted;
Reinstalling or updating your media player can also help resolve codec compatibility issues.