¶ … 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...

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.…