Signing systems that attempted to represent spoken language via manual signs -- some invented, and some borrowed from natural sign languages -- have historically been used in classrooms with deaf children. However, despite decades of research and use of these systems in the classroom, there is little evidence supporting their educational…

The study of effects of mode (manual only, manual plus oral, and manual plus oral plus aural) and language (Signed English or American Sign Language) on the comprehension of deaf students (mean age 16 years) found no significant treatment effect for mode of presentation; there was an interaction between languages and mode. (Author/DB)

The study with 23 severely hearing impaired adolescents found that subjects using cued speech performed highest on Piagetian conservation problems, the oral-aural group performed better on linguistically-sensitive metaphor problems. Differences were not, however, statistically significant. (Author/DB)