I know this has been brought up before, I have found posts going back as far as seven years requesting a read-aloud feature, especially for math courses. I have not found a Chrome extension that reliably works on Khan Academy. 

The United States Department of Health and Human Services estimates that 15% of the U.S. population has dyslexia. Many of these students are great at math! Sadly, their reading deficit prevents them from practicing and improving their math skills, and their confidence takes the hit. 

Please prioritize the development of a read-aloud/text-to-speech feature.