About Creating Accessible Tables Source: https://webaim.org/techniques/tables/

Accessible multimedia (visual and auditory content that is synchronized) must include captions—text versions of speech and other important audio content—allowing it to be accessible to people who can't hear all of the audio. © WebAIM 

Adding alternative text for images is the first principle of web accessibility. It is also one of the most difficult to properly implement. The web is replete with images that have missing, incorrect, or poor alternative text.