Describing the trajectory of language development in the presence of severe-to-profound hearing loss: a closer look at children with cochlear implants versus hearing aids.

OBJECTIVE The objective of this investigation was to describe the language growth of children with severe or profound hearing loss with cochlear implants versus those children with the same degree of hearing loss using hearing aids. STUDY DESIGN A prospective longitudinal observation and analysis. SETTING University of Colorado Department of Speech Language and Hearing Sciences. PATIENTS There were 87 children with severe-to-profound hearing loss from 48 to 87 months of age. INTERVENTION All children received early intervention services through the Colorado Home Intervention Program. Most children received intervention services from a certified auditory-verbal therapist or an auditory-oral therapist and weekly sign language instruction from an instructor who was deaf or hard of hearing and native or fluent in American Sign Language. MAIN OUTCOME MEASURES The Test of Auditory Comprehension of Language, 3rd Edition, and the Expressive One Word Picture Vocabulary Test, 3rd Edition, were the assessment tools for children 4 to 7 years of age. The expressive language subscale of the Minnesota Child Development was used in the infant/toddler period (birth to 36 mo). RESULTS Average language estimates at 84 months of age were nearly identical to the normative sample for receptive language and 7 months delayed for expressive vocabulary. Children demonstrated a mean rate of growth from 4 years through 7 years on these 2 assessments that was equivalent to their normal-hearing peers. As a group, children with hearing aids deviated more from the age equivalent trajectory on the Test of Auditory Comprehension of Language, 3rd Edition, and the Expressive One Word Picture Vocabulary Test, 3rd Edition, than children with cochlear implants. When a subset of children were divided into performance categories, we found that children with cochlear implants were more likely to be "gap closers" and less likely to be "gap openers," whereas the reverse was true for the children with hearing aids for both measures. CONCLUSION Children who are educated through oral-aural combined with sign language instruction can achieve age-appropriate language levels on expressive vocabulary and receptive syntax ages 4 through 7 years. However, it is easier to maintain a constant rate of development rather than to accelerate from birth through 84 months of age, which represented approximately 80% of our sample. However, acceleration of language development is possible in some children and could result from cochlear implantation.