No audio on some tracks
Sometimes, audio doesn't work. I'm a developper myself so I used the chrome inspector to see what's up and it seems that some of your static assets have permissions denied. Example:
Hope that helps.
Thanks for trying to help Duolingo fix their problems. I'm not sure how many staff members look at the discussions so it's probably best to tell them using the "Support" button which appears on the extreme left of the browser window. The button can also be used to report App problems.