The Library of Congress has a collection of sound files of people speaking North American English. They show the different words used by people of several regions, and their accents.
Some files also have transcripts (written copies).
The Center for Applied Linguistics made the recordings between 1941 and 1984. They took place in 43 states, the District of Columbia, Puerto Rico, and Canada.
You can see the list of files here.
Printable:Download listen to english.pdf (18.0K)