For people wanting different recordings of the garbled/non-garbled: it's right on the page right above the one Morendil linked to.

On the next sample, I only caught the last few words on the first play (of the garbled version only), and after five plays still got a word wrong. On the third, I only got two words the first time, and additional replays made no difference. On the fourth, I got half after one play, and most after two. On the fifth, I got the entire thing on the first play. (I'm not feeling as clear-headed today as I was the other day, but it didn't feel like a learning effect.) On some of them, I don't believe that even with a lot of practice I could ever get it all right, since some garbled words sound more like other plausible words than they do the originals.

Thinking about it more, it's a bit surprising that I did well. I generally have trouble making out speech in situations where other people don't have quite as much trouble. I'll often turn on subtitles in movies, even in my first language/dialect (American English). (In fact, I hate movies where the speech is occasionally muffled and there are no subtitles--two things that tend to go hand in hand with smaller production budgets.) OTOH, I have a good ear in general. I've had a lot of musical training, and I've worked with sound editing quite a bit.