"Speech with a drawl, twang, clipped consonants, broad vowels, slurred words or extra diphthongs might give away that the speaker is from the American South, Boston, the Midwest or elsewhere. The spice that a certain region may lend to spoken language can even be strong enough to flavor non-audible language as well. Indeed, American Sign Language (ASL) has its own accents. And like its audible counterpart, one of the strongest regional accents in ASL is that of Philadelphia residents, reports Nina Porzucki for PRI."
Via Seth Dixon