I have the same problem with the audio on shows, too. I’ve resorted to using the closed captioning option, and it helps.
Same with movies - I always use subtitles on DVDs. Alot of people don’t like them, but you get used to it over time I think.
Do they actually pick up the mumbles?
I've watched TV while on the treadmill at the gym and the stuff that comes across the subtitling is absolutely laughable. But then again, it's usually live feed on news broadcasts......