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Deaf children with a cochlear implant who had no exposure to sign language fared better with speech, language, and reading comprehension than children with sign language exposure, researchers found.

In an observational study, a lower portion of children with no exposure to sign language produced less intelligible speech as young children, had higher language comprehension scores, and fewer were likely to have delayed language development, reported Ann E. Geers, PhD, of the University of Texas at Dallas, and colleagues.

Writing in , the authors cited the "paucity of data" comparing spoken language outcomes of deaf children learning language with or without learning sign language. Other studies found conflicting results -- from that argued "the benefits of learning sign language outweigh the risks" to one that stated "" exists on whether sign language is effective with oral language therapy.

An by Karl R. White, PhD, of Utah State University, and Louis Z. Cooper, MD, of Columbia University, characterized the research as an example of how "well-designed research" can provide "credible and useful information."

"Instead of relying on anecdote and argument as the basis for policy and practice, [we] can help end the passionate but debilitating debates between advocates of signing and non-signing, while offering useful guidance to families with children who are [deaf or hard of hearing] and their healthcare providers," they wrote.

Geers and colleagues examined a cohort of 97 children from the . Parents answered questions about the child's exposure to sign language prior to receiving a cochlear implant, as well as 12, 24, and 36 months post-surgery. No sign language was defined as none used from baseline through the first 3 years following surgery. Short-term sign language exposure was defined as sign language use at baseline and/or 12 months following surgery, but not at 24 or 36 months later. Long-term exposure was defined as sign language exposure through 36 months after surgery.

Researchers measured early auditory development through the (SRI-Q) and speech intelligibility was assessed by three judges listening to audio recordings made of each child imitating 36 sentences. Spoken language was measured by the Core Composite standardized score on the (CASL) and reading was measured via the of Woodcock-Johnson Tests of Achievement.

Overall, a significantly higher portion of children with no exposure to sign language had intelligible speech as young children compared to those with both long-term sign exposure (mean 70.4% versus mean 50.9%, respectively, P<0.001) and short-term exposure to sign language (mean 70.4% versus mean 63%, respectively, P=0.01).

Language scores were significantly different among sign language exposure groups, and significance increased over time, the authors said. By late elementary school, children with no sign language exposure had an average language score of 96.2, which was close to the "normative mean" of 100, while mean scores for children with exposure to sign language were lower (83.8 and 76.4 for short- and long-term exposure groups).

The portion of children with delays in spoken language or reading dropped significantly between the early and late elementary school grades (44% to 29% among the no sign language exposure group). However, 58% of children with short-term sign language exposure had spoken language delays in both early and late elementary school, and 61% of children with long-term sign language exposure still reported them in the late elementary school years.

The editorialists also noted other "important findings for clinicians and parents," such as that those children with no sign language exposure "were 3.5 to 4 times less likely than signers to have delayed mastery and scored ~0.6 and 1.3 standard deviations higher in language and reading."

Limitations to the study included that the children were from families with normal hearing and not native signers, as well as potential unmeasured confounders between the three groups of parents and children prior to cochlear implantation. The authors also noted that more than half of the mothers in this study had college degrees, which may limit its generalizability.