No Film for Old Ears

OK. I admit it. I'm what is called these days an 'older adult'. I prefer older git. Not yet at the dribbling and incontinent stage but proud holder of bus pass. Most parts work well (legs, arms, isolated areas of brain) and I still enjoy the sound of popular beat combos. Very occasional problems in the hearing department, e.g. conversation at noisy party, embarrassed to say 'Pardon' yet again, so in response to "Unfortunately my dog has just died", am inclined to respond with something like "Excellent, that is good news!".
And so to No Country for Old Men. Set as it is in rural Texas this was always going to be a challenge. But the Coen Brothers are proud of their dialogue and a lifetime of listening to Hollywood means that lines like "mardy farn chur pah murylu y'all" can be taken at a canter. But I have to say I struggled - piecing together the dialogue from those words I understood. Don't get me wrong, I'm a big fan of the Coen Brothers. Worth the admission for the opening sequence to Fargo alone. And this is a good film with an impressive baddy and plenty of their trademark quirkyness (though the quirk count is difficult to measure when you are frustatingly missing what you suspect is razor sharp dialogue).
I'm also aware that it's unfair to single out No Country for Old Men, because there are many other films much worse than this. And it's usually the men. I blame Brando, since whom mumbling has become a sign of virility. And what about the sound system at the Courtyard? How much does this contribute? I do know that I rarely have problems with anything other than the southern drawl.
So compare and contrast. The Band's Visit is a low budget film from a new Israeli director. It's an absolute gem and must be seen, although probably won't be in the places where it should. The dialogue is part modern Hebrew, part Egyptian, and part in the only common language of English. This is 'common language' in a broad sense, in that I suspect quite a few of the actors didn't speak English at all. In view of the sometime idiosyncratic delivery, all of the film had subtitles, which I found unnecessary for the English speech. So I can understand an Egyptian speaking in a language he doesn't understand, but not an American speaking in a language that he does.
What is to be done? Short of sending all American mumblers to an elocution school run by Maggie Smith and Judi Dench, there may be a way. Certify American films set below the Mason-Dixon Line by giving them a 'Mumble Rating'. Failure to deliver lines with clarity would result in compulsory subtitles.
Or is it just me?