The English language development of an unselected group of 20 hearing-impaired children taught Signed English was studied over a 4-year period. The children were enrolled in residential and day school settings. Their language development was individually tested annually with the Peabody Picture Vocabulary Test, the Northwestern Syntax Screening Test, and a tailor-made Signed English Morphology Test.
Over the 4 years, the children's receptive vocabulary grew at the rate of 43% of that manifested by hearing children. The vocabulary level reached at age 8 was similar to that reported for comparable hearing-impaired children at age 11 taught by other methods.
There was no apparent syntax development until after the first year. For the succeeding 3 years, however, syntax developed at a steady and, seemingly, accelerating rate.
There was little growth in the children's ability to speechread single word utterances when they were presented orally.
After 4 years all but two children simultaneously spoke and signed every word in the test situation. It is doubtful, however, that the quality of their speech improved very much if any.
After 3 years, mothers were judged, on the average, to have acquired somewhat between a beginner and an average skill in Signed English. Fathers, on the other hand, did not get beyond the beginner's stage.