New research shows that a higher proportion of shape-based nouns in a child’s vocabulary shortly after cochlear implantation is associated with better language development for the next three years.
The study found that children with a larger proportion of shape-based nouns in their vocabularies shortly after implantation had larger vocabularies at one year, two years, and three years after implantation.
They also scored higher on standardised tests of other language abilities, and they were more likely to have caught up with their peers with normal hearing.
The researchers said before this study, little was known about the role of shape-based nouns in the language development of children with cochlear implants. The findings suggested that knowing shape-based nouns facilitates children’s language development and may help to make up for initial language delays in children with cochlear implants.
The University of Miami study published in Developmental Science offers new insights into language development in children with hearing loss, suggesting language learning strategies that may help children with cochlear implants overcome initial language development delays.
University of Miami researchers Associate Professor Lynn Perry, Profesor Daniel Messinger and Professor of Clinical Otolaryngology at Miller School of Medicine University of Miami Ivette Cejas conducted the study.
It sheds light on the relationship between early vocabulary knowledge and later language development in children with cochlear implants.
The researchers focused on the proportion of shape-based nouns in children’s initial vocabularies. Shape-based nouns are words like “chair” or “cup” that describe a category of objects based on their shape, rather than other characteristics such as colour or material.
They also found that the association between the shape-based nouns and long-term language development was stronger in children who had received cochlear implants, compared to children with normal hearing.
The results have implications for efforts to help children with hearing loss surmount initial language delays caused by a lack of auditory input and access to speech sounds before they receive cochlear implants.
“Learning more shape-based nouns seemed to affect both how many words they knew and also their grammar skills and other aspects of language,” said Associate Professor Perry from the Department of Psychology, the first author on the paper.
“Especially for the children with cochlear implants, it was such a strong predictor that even three years later, we were able to account for some of the differences in their language skills.”
The data used in the study was collected as part of the Childhood Development after Cochlear Implantation Study, a national, multi-site longitudinal study. The researchers analysed data on the language abilities of young children with cochlear implants before their implantation surgery and every six months after implantation. They also looked at data on children with normal hearing who were recruited from preschools.
Previous studies have indicated the importance of shape-based nouns in the language development of children with normal hearing, and that picking up on this pattern in early-learned English vocabulary can help children to acquire new words. But before this study, little was known about the role of shape-based nouns in the language development of children with cochlear implants.
“This is a real experiment in nature showing that the types of words a child knows shape their language development,” said Professor Messinger from the Department of Psychology. “It’s remarkable that these effects were strongest for cochlear implant users, perhaps because shape-based nouns guided their word learning after implants gave them access to hearing.”
Prof Cejas added: “While cochlear implants have become the standard of care for children with bilateral severe to profound hearing loss, there continues to be significant variability in their spoken language development.
“Our work highlights a potential avenue for intervention that may aid in closing the vocabulary and language gap that exists for some of these children.”
Although the study found an association between the initial proportion of shape-based nouns in a child’s vocabulary and later language development, the researchers said further investigation was needed to establish a causal link.
They said they don’t yet know why some children had a larger proportion of shape-based nouns in their vocabulary than others.
“Both within the group of children who have cochlear implants and children in general, we do see differences in terms of what words children learn first,” Prof Perry said. “I think figuring out where those differences come from will be important to knowing how to best support all learners.”
The National Institute on Deafness and Other Communication Disorders of the National Institutes of Health supported the study.
