This paper is devoted to the study of a pseudo-phonetic approach to characterize prosodic disorders of children with impaired communication skills. To this purpose, we have designed with the help of the clinicians’ staff a database containing autistic children. Another database with non disordered speech is used as a control one. Concerning the characterization of the prosodic disorders, we extract the features from phonemic units such as vowels. These segments are provided by a pseudo-phonetic speech segmentation phase combined with a vowel detector. Since the pseudo-phonetic segments convey a lot of prosodic features, such as duration and rhythm, many differentiations can be made between children from the two studied databases. As a conclusion, correlations between prosodic particularities got in this study and those described in the literature are given.