Learning German, advice or help appreciated!

[Alex K]

I've often wondered what exactly the difference is with the south German accent and hoch Deutsch. How would other Germans describe it?

I have occassionally heard some Bavarians talk with a really nasally sound, it's odd and is very difficult to describe. It's like they are always talking from the back of their throat. I was wondering if they are from Nieder Bayern.

Uuhh ohh. That's a tough one. When I don't speak high German on purpose, I have a southern German dialect/accent, so I should know. But the differences are too numerous and subtle for me to be able to summarize them. Generally, southern German has missed some vowel shifts and similar developments that high German has undergone (and therefore, oddly, sometimes has some similarities with English: for example, we also say "a" instead of high German "ein").
Some features (strongly simplified): endings tend to be shortened or omitted (machen -> mache, Sachen->Sache), "ü" -> "i", "ö"->"e", in some cases "ei" -> "ä" or "a", "t"->"d", "p"->"b", and similar substitutions. The regional dialects usually feature a less elaborate grammar where e.g. some forms of past tense are never used, and Genetiv is always avoided in favour of a less sophisticated sounding Dativ construction with a possessive pronoun ("Die Tochter des Mannes" -> "Dem Mann sei Dochder).