Is there a way to adjust the sound settings for clear dialog in videos played using Vivitar SD Card Reader ?

Has anyone had an issue connecting, causing issues w/images or videos? I know my body cam has sound…I stopped when a particular video had no sound… and I need to hear dialog. Hopefully an adjustment gives me the clear dialog that went on… this is possibly a legal issue.I can’t afford to lose the sound aspect of this video…Any ideas??

Thank You!!!

[Re-Titled by Moderator]