In this second of two studies conducted with portions of the National Speech and Hearing Survey data, the investigators analyzed the phonetic variants from standard American English in the speech of two groups of nonstandard English speaking children. The study used samples of free speech and performance on the Gold-Fristoe Test of Articulation from a group of 192 Black children (grades 1-6 from Niagara Falls, New York, and a group of 192 Mexican-American children (grades 1-6) from San Antonio, Texas. The study reports the frequencies of omission, substitution, and distortion. The present data is compared with the previously reported results obtained from standard American English speakers from Marshall, Iowa. The major conclusion is that all phonetic variations from standard American English can be attributed to one of the following sources of variation: (1) reduction in the complexity of segments, which usually decreases with age; (2) differing phonological rules between standard English and a dialect of English; and (3) phonetic interference between a foreign primary language and English. (See also ED 042 756, ED 042 757, ED 042 758, ED 046 938, ED 052 213) (CF)