Spoken Language and Bilateral Cochlear Implants
Sarant et al (2014) compared the spoken language outcomes of children with unilateral and bilateral cochlear implants (CIs). The authors report that “bilateral cochlear implantation is becoming the standard of care….” They note that bilateral CIs offer binaural redundancy through the involvement of two ears. The brain has two opportunities to process sound: (1) binaural summation (the increased loudness availed via 2 ears) and (2) the head-shadow effect (the head acting as a barrier and therefore reducing the loudness at the ear farther from the sound source). Sarant et al note that Hughes and Galvin (2013) reported “objective evidence that for some children with bilateral CIs, listening effort is reduced, suggesting that more attention can then be paid to the learning process….”
The authors evaluated 91 children (44 boys and 47 girls) at ages 5 or 8 years using the Peabody Picture Vocabulary Test (PPVT), and either the 4th edition of the Preschool Language Scales (PLS) or the 4th edition of the Clinical Evaluation of Language Fundamentals (CELF).
Sarant et al report that their outcomes demonstrated children with bilateral CIs “achieved significantly better vocabulary outcomes than did comparable children with unilateral CIs….” With regard to language outcomes, the results showed no significant advantages for bilateral CIs. However, children with bilateral CIs did have significantly faster rates of language development as measured by the CELF and the PLS. The authors concluded that “overall, bilateral CIs contributed to significantly better language outcomes…” and they note parenting style (the amount of time spent reading to the child and the amount of screen time, etc.) influenced language outcomes. Specifically, as screen time was reduced and reading time increased by 30 minutes daily (150 minutes per school week), a significant increase was observed in the PLS Total Language Score (15.66 points). The authors report that “this large predicted increase in scores demonstrates how effective relatively small changes in parenting can be in facilitating significant changes in children’s language development.”
For More Information, References and Recommendations
Holt R, Svirsky MA. (2008) An Exploratory Look at Pediatric Cochlear Implant. Ear & Hearing 29(4):492-511.
Hughes KC, Galvin KL. (2013) Measuring Listening Effort Expended by Adolescents and Young Adults With a Unilateral or Bilateral Cochlear Implants or Normal Hearing. Cochlear Implants Int14:121-129.
Leigh J, Dettman S, Dowell R, Briggs R. (2013) Communication Development in Children Who Receive a Cochlear Implant by 12 Months of Age. Otology & Neurotlogy 34:443-450.
Nicholas, JG. And Geers, AE. (2013): Spoken Language Benefits of Extending Cochlear Implant Candidacy Below 12 Months of Age. Otology & Neurotology 34:532-538.
Ramsden JD, Gordon K, Aschendorff A, Borucki L., Bunne M, Burdo S, Garabedian N, Grolman W, Irving R, Lesinski-Schiedat A, Loundon N, Manrique M, Martin J, Raine C, Wouters J, Papsin BC. (2012) European Bilateral Pediatric Cochlear Implant Forum Consensus Statement. Otology & Neurotology 33:561-565.
Sarant J, Harris D, Bennet L, Bant S. (2014) Bilateral Versus Unilateral Cochlear Implants in Children: A Study of Spoken Language Outcomes. Ear & Hearing 35(4):396-409.