Background and Aim: Hearing impaired children encounter many problems for learning language and communication skills. The aim of this research is to compare morphological skills in conversational speech and story retelling of hearing impaired with typically normal children.

Materials and Methods: In this cross sectional analytic research 16 typically normal and 9 hearing impaired children between 48 to 72 months were selected in a convenience sampling method .After considering inclusion and exclusion criteria, linguistic sampling for conversational and story retelling data was gathered. Parametric, nonparametric statistical analysis and U Mann-Whitney and t- test was performed on gathered data.

Results: In story retelling there was significant difference between using conjunction,whole free grammatical morphemes, clitics, zero morphemes (p˂0.05). There were significant differences between using conjunction, proposition, conversational grammatical morphemes, inflectional affixes, clitics zero morphemes and whole bound grammatical morphemes in conversational speech (p˂0.05).

Conclusions: Hearing impaired children have more morphological errors than typically normal children. They tend to omit lexical morpheme in story retelling, but typically normal children tend to substitute a lexical morpheme with another one in story retelling. The most kind of error in both groups was omission of morpheme in conversational speech.

Keywords: Hearing impaired children, Morphological errors, Conversational and Story retelling