The Atlas of North American English provides the first overall view of the pronunciation and vowel systems of the dialects of the U.S. and Canada. The Atlas re-defines the regional dialects of American English on the basis of sound changes active in the 1990s and draws new boundaries reflecting those changes. It is based on a telephone survey of 762 local speakers, representing all the urbanized areas of North America. It has been developed by Bill Labov, one of the leading sociolinguists of the world, together with his colleagues Sharon Ash and Charles Boberg. The Atlas consists of a printed volume accompanied by an interactive CD-ROM.