The aim of the study is to reveal the specificity of the perceptual and acoustic characteristics of the speech utterances of preschool children with developmental disorders brought up in the orphanage, in comparison with the typically developing children brought up in the family. Сhildren from an orphanage with mental retardation and mixed specific psychological development disorders use less complex dialogue replicas than typical developing children; the features of their lexicon are described. Perceptual and acoustic features of the words of orphans are revealed. The high frequencies of the pitch and the longer duration of the stressed vowels from the words of children with mental retardation are shown. The results of the research could be used to build the strategies for interaction with children with developmental disabilities, for elaboration of existing methods of teaching children, including alternative communication techniques.