Sound is not required for all demos (some are silent except for typing and mouse clicking sound effects).
These brief & simple online demonstrations (in tutorial style) will show some of the basic capabilities of CSS HTML Validator Pro.
NOTE: The demos are silent except for typing and mouse clicking sound effects.
Validation Demo (6 min) - HIGHLY RECOMMENDED!
Tools Demo (2.5 min) - shows the uppercase, lowercase, quote, and remove tags/extract text tools. NOTE: This demo is based on an old version of CSS HTML Validator, but is still useful.
The below video is from a beginner CSS course offered by Andy Williams on Udemy.com. The course name is CSS - Comprehensive CSS for beginners. It's a short introduction to CSS HTML Validator.