Manifestation of speech language disorders in children with hearing impairment versus specific language disorders

¶ … Manifestation of speech and language disorders in children with hearing impairment compared with children with specific language disorders" examined the relationship between language deficits among children with hearing impairment (HI) compared to those with specific language impairment (SLI). By studying the receptive language skills of 5 and 6-year-old children with HI and SLI the researchers concluded that the receptive language skills of children with HI were more impaired. They also asserted the importance of phonological short-term memory impairment in both children with HI and SLI, although the basis of which can be traced to different causes. Finally the authors concluded that deficits in language ability that are caused by hearing impairment affect receptive language skills more than expressive ones.

When a child grows up with a hearing impairment it often affects the child's ability to speak. The severity of speech and language disorders caused by hearing impairment has been found to be related to the degree of HI, the age at which treatment is begun, as well as the involvement of the mother. However, children with impairments to their hearing are not the only ones who develop speech disorders, sometimes children with normal hearing can develop specific hearing impairments (SLI). While the exact causes of specific language impairment are not known, researchers have asserted a connection between SLI and problems with a child's phonological short-term memory. They have also discovered a relationship between children with HI and problems with their phonological short-term memory. Additional research has concluded that while children with SLI may have an intrinsic limitation in their phonological memory capacity, the memory capacity of children with HI seems to be overtaxed by their hearing deficiency. The authors of the current study sought to study the relationship between deficiencies in the receptive language skills of children with HI compared to those with SLI in light of understanding the causes and role of phonological short-term memory deficiencies.

Subjects for the study were chosen from a pool of children who were enrolled in an intensive speech, language, and perception training course and had at least 1 year of outside treatment. From 242 children enrolled in the course, 24 children with hearing impairment were chosen as subjects, 17 boys and 7 girls. These children had been diagnosed with bilateral, sensorineural hearing impairment, had used hearing aids prior to the study, but none had the progression of their hearing loss documented. As part of the study, "each child with HI was matched to a child with SLI that was the same age, the same sex, and had nearly the same severity of speech and language disorder, and non-verbal intelligence." (Keilmann, 2011, p.13) Severity of speech and language disorder was graded by testing the child's receptive language skills, vocabulary, grammar and output phonology.

While strictly speaking the researchers did not use a "control group" that was unaffected by any hearing loss, the children with HI can be considered the control group for the purpose of this study. It was they who set the number of subjects and they to whom a group of children with SLI were compared. The children with HI had their receptive language skills tested with the Reynell Development Language Scales I, their vocabulary tested with the "Aktiver Wortchatztest 3-6," grammar with the Ravensburger Dysgrammatiker Prufmaterial, and phonology by means of the Neuer Mainzer Laustatus picture-naming test. As a comparison to the results generated by testing the children with HI, the paired children with SLI were tested identically. As the study was done in Germany, all language tests were performed in German by a clinical psychologist "with experience in working with deaf children and those with severe language impairment…." (Keilmann, 2011, p.13) Finally the Statistical Package for Social Sciences (SPSS) was used to perform statistical analysis of the data.

By performing this study the authors determined that children with HI and those with SLI both express impairment of their receptive language skills; and this is linked to the impairment of the child's phonological short-term memory. However, the impairment of the short-term memory seems to come from different causes. Children with SLI have an intrinsic impairment while those with HI seem to overload their memory due to their hearing deficiencies. Finally the authors conclude that SLI language deficiencies affect the expressive language skills of children more than their receptive ones, the opposite is true in children with HI. Because of their hearing impairment, the receptive language skills of children with HI are much more affected by their deficiency than their expressive ones.