Infants with permanent hearing loss benefit in terms of language development from being enrolled very early -- before 3 months of age -- in intervention programs, according to a new study.
Normally, children with moderate to profound hearing loss exhibit delayed language skills at 12 to 16 months of age, compared with children with mild to minimal hearing loss, the researchers explain in the medical journal Pediatrics.
Previous research indicates that children who are deaf or have hearing loss who are not diagnosed early and do not receive early intervention for language development do not catch up to their hearing counterparts in language skills, or in "social skills, literacy, and academic skills, resulting in lower potential employment levels as adults," Dr. Betty Vohr, of Brown University, Providence, Rhode Island, and colleagues point out.
However, evidence began to accumulate in the 1990s "that children with hearing loss who received intervention services before 6 months of age had language scores comparable to those of hearing children at 3 years of age."
In the current study, the researchers examined the early language outcomes of 30 infants with mild to profound hearing loss -- some of whom had received early intervention -- compared with 96 "controls" with normal hearing.
Compared with children with mild to minimal hearing loss and the controls, those with moderate to profound hearing loss had significantly lower scores for phrases understood, words understood, words produced, and gestures.
Enrollment in early intervention, up to 3 months of age, was associated with significantly higher scores for number of words understood, words produced, and gestures, compared with infants enrolled at 3 months of age or older.
It is not known if children with moderate to profound hearing loss will be able to "catch up" with the children with mild to minimal hearing loss, the investigators note.
It is also not clear if the mild to minimal hearing loss group will begin to lag behind their normal-hearing peers as language skills become more complex and exposure to noisy environments increase.