pronunciation of "utt" words
I'm a little confused right now about words with a U and double T in them and how the U would be pronounced. I know in the word "Mutter" the U is pronounced like an English U. Though when someone German pronounces my name, the say Duttenhofer, with the English double O. Is there a rule for this? Ohh and if you happen to know what Dutten means that would be great. Thank you.

Question

Answer

A German "u" is always pronounced like an English "oo".
Doubling consonants in German, however, means that the preceding vowel should be pronounced short.

Have look at this dictionary, which also has the pronounciation
http://dict.leo.org/ende?lp=ende&lang=de&searchLoc=0&cmpType=relaxed&sectHdr=on&spellToler=&search=mutter
http://dict.leo.org/ende?lp=ende&lang=de&searchLoc=0&cmpType=relaxed&sectHdr=on&spellToler=&search=Dutt

I also did some research on the family name Duttenhofer.
I first looked for "Duttenhofer" and "Duttenhöfer". Later, I found that the spelling "Dudenhöfer" also exists.

Some people extract the telephone book to get statistics about the distribution of family names. See for example
http://christoph.stoepel.net/geogen (type in a name to get links to maps)
http://www.verwandt.de/karten/absolut/duttenh%25C3%25B6fer.html
http://www.verwandt.de/karten/absolut/duttenhofer.html
http://www.verwandt.de/karten/absolut/dudenh%25C3%25B6fer.html
The Duttenhofers live predominantly in the south west of Germany.

And then, there is a place named "Dudenhofen"
http://maps.google.de/maps?f=q&source=s_q&hl=en&geocode=&q=dudenhofen&sll=51.151786,10.415039&sspn=26.131022,28.256836&ie=UTF8&hq=&hnear=Dudenhofen,+Rhein-Pfalz-Kreis,+Rheinland-Pfalz&ll=49.312813,8.414841&spn=0.211288,0.351563&z=12