In your sidebar, you have linked to your feed as:
This is, of course, wrong in a few ways. Currently, you do not have permalinks active, so your correct feed URL is currently this:
If you did have permalinks active, the correct feed URL would be:
Now, as you can see, http://audiolingo.org/wp-rss2.php does have a bit of a validation problem:
I would recommend first replacing the wp-rss2.php file with a fresh copy from a new WordPress download. If that doesn't work, try replacing wp-feed.php, then your main index.php file, then your theme's header.php file. If neither of those work, disable all of your plugins and check your theme's validation again.
Basically, that blank line and the "home/audikin8/www/wp-rss2.php" line are getting in there somehow, and they shouldn't be there. Blank lines in feeds can be caused by blank lines at the beginning or end of any WordPress file, but I have no idea how the "home/audikin8/www/wp-rss2.php" is getting in there.