Hi Art,
This is Wil, one of the independent advisor, an expert with Windows 10 and a fellow Windows 10 user like you. I understand your concern about sound issues when watching videos.
May I ask what application are you using when playing videos? Are you having the same issue when watching videos on Youtube.com? Let's try this troubleshooting. Open the video where you are having a sound issue. Right-click on the sound icon on the system tray (bottom-right part beside date and time) and choose volume mixer. Make sure that all sounds for all applications are not muted.
I hope my suggestions help you. If you need further assistance please do reply back and I will respond as quickly as possible. Have a nice day.
Thanks,
Wilfred P.
Independent Advisor