Effects of Age at Cochlear Implantation on Vocabulary and Grammar: A Review of the Evidence
American Journal of Speech-Language Pathology
Duchesne, L., & Marschark, M. (2019).
American Journal of Speech-Language Pathology, 28(4), 1673-1691.
This systematic review investigates the effects of age at cochlear implantation on vocabulary and grammar development in children with hearing loss.
Not stated
1998 to 2018
Group design studies
49
For children who receive cochlear implants (CI), "overall, the reviewed evidence suggests only a moderate influence of age at implantation on central components of language" (p. 1685). This review found that earlier implantation results in better short-term language outcomes during the period three months to 3-4 years after implantation. Some studies indicated decreasing effect sizes for receptive and expressive language outcomes over time; however, studies investigating long-term speech and language differences are limited. Studies employed a variety of cut-off ages to define "early implantation," so no specific age was identified as an ideal age for CI. Studies investigating the ability to use age of CI as a predictor of language outcomes reported inconsistent findings. In addition, most studies found additional variables that also predicted language outcomes such as family income/socioeconomic status, maternal level of education, gender, cognitive skills, residual hearing, parent-child interactions, pre-implantation language skills, and school placement.
