Abstract
The ways in which blind babies and children use electronic sensory substitutes are related to their perceptual development. Previous studies suggested that there is a critical age—13 months—after which children find it difficult to use a device such as the Sonicguide. The results of this study of five blind children aged 5–48 months question the suitability of behavioral cues that have been chosen to determine this critical age. The specific development of blind children and its implications are also discussed.