Dr. William Kronenberger explains how hearing loss and cochlear implants can affect the brain development of children.
Cochlear implants are small electronic devices with multiple components that are worn outside the body and implanted under the skin. When children get them, it’s typically between the ages of 2 and 6. Dr. Kronenberger is a professor at the Indiana University School of Medicine.
Interview Highlights:
Lewis: We’re focusing this week on learning and how various childhood conditions can affect brain development and how children interact with the world around them. Let’s start with this, from child psychologist William Kronenberger.
Kronenberger: Our genes really set up the rules for brains to develop, but beyond that the way the brain develops depends on the experiences the person has.
Lewis: Dr. Kronenberger is a professor of clinical psychology at the IU School of Medicine. He focuses on brain development in children.
Kronenberger: Each person has a certain type of experience that affects brain functioning and the brain learns from that and there actually is change in brain development. So when there is a significant deviation in someone’s exposure to a type of sensation like hearing, there can be a significant impact on brain development
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Kronenberger: A cochlear implant is a device that converts sound into an electronic stimulus, which is then sent to the auditory nerve. What that allows is someone who has a certain type of hearing loss, a certain type of deafness, it allows them to have access to sound by essentially presenting the electronic stimuli directly to the auditory nerve. The brain then is able to perceive the sound.
Lewis: Recently, he told me about a study of a group of children who had received cochlear implants to see how their brains had been affected by hearing loss.
Kronenberger: There are at least two very important things that hearing offers to brain development. One is the idea that things occur in sequences. When you listen, you hear things occurring one after the other and it teaches the brain to process information sequentially. And sequential processing is important for things like planning and looking at where you are in the present and then making a plan or executing a set of steps to get to the future. There’s an early brain influence of sequential processing. The other area that hearing is very important for is language development. Very early on, even during fetal development, the infant is exposed to sounds of language and certainly after birth, much language development occurs.
Lewis: You recently worked on a team that worked with kids with cochlear implants.
Kronenberger: One thing that’s important to know about cochlear implants is that they aren’t as good as the ear. They’re remarkable devices, they allow access to sound, they allow the development of spoken language. But there is some degradation in what they’re able to pass on to the auditory nerve.
Lewis: So when you say degradation, is it that they don’t hear as clearly?
Kronenberger: The details of the sound are not as rich. So you might think of it as, even when you listen to the radio, the details of the sound are not as rich as when you’re actually in person with someone, or think of over the phone. Where you notice it the most with a cochlear implant, it’s harder to detect sound within background noise. So for example someone talking within background noise would be harder for someone with a cochlear implant to perceive. ON the other hand, in quiet, modern cochlear implants are remarkably good at transmitting sound. And again, what we find is children with hearing loss, who would typically have no potential or very little potential for the development of spoken language, are typically able to develop spoken language with the input of the cochlear implant.