An equivalence model for vocabulary acquisition in profoundly hearing-impaired children

The purpose of this study was to determine the generality of Sidman's (1971) equivalence model when applied to vocabulary acquisition in deaf preschool children. The model specifies six vocabulary tasks involving auditory and visual sensory modalities. The data confirmed that lip reading (visual modality) could be substituted for auditory input (speech). However, for novice lip readers, words with auditory-visual confusions depressed performance on receptive vocabulary tasks, in contrast to the emergent expressive performances. The results are discussed with respect to the applicability of the equivalence model to education of deaf children using a computerized system. It is suggested that the computer system provides a standardized method for assessment of mechanical and cochlear implant prosthetic devices.