Please follow these steps
1. Go to this site:
2. Forbibid scripts globaly using NoScripts.The instructions will not render with Scripts Enabled. Not sure why.
3. This Subheading( Heading, Header, Paragraph title ) along with instructions will appear.
You may need to install the required PulseAudio software
If you see a notification saying "To play audio, you may need to install the required PulseAudio[…]
4. When done reading, enable scripts (Java Scripts) so Youtube will work.
Note: It is strongly recommended that you Forbid Scripts Globally by default and only enable them on a case by case basis.
Ohh OK. I thought you found that on one of the Whonix wiki pages.