What happens during a baby’s first few months of life is nothing short of extraordinary. He begins to take in the world around him through all of his senses; learning more about his environment with everything he sees, hears, tastes, and touches. But what happens when one of these senses is missing, as in the case of a deaf newborn?
Speech development in hearing-impaired infants
When an infant is born with any type of hearing impairment, whether it be complete deafness or a milder form of hearing loss, other areas of development can be affected. When a child cannot hear or hear well, research has shown that speech development is often delayed and social interactions are impacted. What hasn’t been widely studied, however, is the effect that hearing has on cognitive skills.
Processing of visual cues in deaf babies
A study by researchers at the Ohio State University Wexner Medical Center recently looked at the effect of hearing impairment on cognitive development in babies who were born deaf. Specifically, they compared how deaf infants processed visual stimuli with the responses of hearing infants who were exposed to the same visual cues.
When babies with normal hearing look at a visual stimulus, they lose interest in it and look away once their brain has processed what they’ve seen. This is known as habituation. Since individuals with one impaired sense often compensate for it by overdevelopment or acuteness of another sense, it was expected that deaf babies would be better at processing visual stimuli than their non-hearing-impaired counterparts.
The results of the study were surprising. The deaf babies actually took longer to habituate to the visual stimuli than babies with normal hearing, making it appear that the hearing impairment interfered with the cognitive processing of the stimulus. In further digesting the results, however, researchers cautioned that the results could be interpreted another way – deaf babies may not actually be learning slower than hearing infants, but may instead be taking extra time to learn more about an object using visual cues since auditory cues are nonexistent.
Cognitive development in deaf babies
While the research did show a distinct difference between the cognitive processing of deaf and hearing babies, it is unclear why these differences occur and exactly what they mean for development. Further research will be needed to determine the cause of these differences, so that appropriate intervention can be applied early in a baby’s life and provide the greatest chance for positive development.