If you are facing this issue, it could be due to one of these two reasons:
Corrupted or wrong file: The video file you have downloaded may not have proper audio embedded in it. Please check the source and quality of the video file you have downloaded.
Unsupported formats (CODEC): Our in-built player supports most of the video and audio formats, but there are some limitations compared to dedicated players. If you try to play a video or audio format that is not supported by our in-built player, you will not hear any sound. In this case, you need to download a dedicated player from the app store that supports all formats.