Early Intervention Key to Hearing Development in Deaf Children

Newswise — A new study by the University of Maryland's Child Development Laboratory and Stanford University shows that early intervention with cochlear implants can make a significant difference in auditory development in deaf children.

In a paper appearing in the December 8 issue of the Proceedings of the National Academy of Sciences, the team found that deaf children who have cochlear implants by the time they are two-and-a-half years old have the best chance of developing auditory abilities close to those of children with normal hearing.

"This study shows the power of early intervention," says Maryland Professor Nathan Fox, director of the Child Development Laboratory, and a co-author of the paper. "We often hear the claim that the earlier you intervene the better, but there are preciously few data on human studies to support this. Our paper is novel in providing evidence for the claim."

Efrat Schorr, a doctoral student in the Child Development Laboratory, Virginie Van Wassenhove a fellow in the University of Maryland Cognitive Neuroscience of Language Laboratory (CNL) and Eric Knudsen, professor of neurobiology at the Stanford University School of Medicine, are co-authors of the paper.

Seeing and Hearing

The Maryland team studied children between the ages of four and 14, who have been deaf from birth and speak English as their primary language. All subjects also had a cochlear implant for at least a year. They were studied over an 18-month period.

"The children who had received the cochlear implants after the age of two-and-a-half did not do as well in the fusion of auditory and visual speech perception as the children who received the implant earlier," says Fox.

The key to auditory development is in the ability to fuse auditory information -- hearing -- and visual information -- lips moving, for example -- a skill that is developed early in life, according to Nathan. "We found that when the speech stimuli were incongruent -- different information from auditory and visual channels -- the children who received cochlear implants before the age of two-and-a-half did almost as well as normal hearing children," says Fox.

"The study shows that children are able to make use of the auditory information with remarkable success when they have a cochlear implant at a young age," says Efrat Schorr.

The study was funded by grants from the American Hearing Research Foundation and the National Institute of Deafness and Other Communication Disorders. David Poeppel, University of Maryland associate professor, provided the stimuli from the CNL Laboratory.

Read more in "A Conversation With..." Nathan Fox: http://www.newsdesk.umd.edu/scitech/Cochlear/main.cfm