cochlear implants, hearing aid
Cochlear implants (CI) can place children at a greater risk of many cognitive problems.Bjorn Knetsch/wikimedia creative commons

Using a hearing aid to treat hearing loss is not as safe as it appears to be.

Cochlear implants (CI), a surgically implanted medical device used to assist hearing, can place children at a greater risk of many cognitive problems, researchers reveal. Depending on this electronic device to treat deafness can lead to deficiencies in executive functioning, including delays in working memory, controlled attention, planning and conceptual learning.

The study looked at executive functioning in 151 children, aged between three and 17. Of the total, 73 children had cochlear implants (CI). During the study, parents provided details of their children's executive function. Cochlear implantation was associated with delays in various mental functions involved in thinking and behaviour.

"In this study, about one-third to one-half of children with cochlear implants were found to be at-risk for delays in areas of parent-rated executive functioning such as concept formation, memory, controlled attention and planning. This rate was 2 to 5 times greater than that seen in normal-hearing children," first author of the study, Dr. William Kronenberger , professor of clinical psychology in psychiatry at the IU School of Medicine and a specialist in neurocognitive and executive function testing, said in a news release.

Remarkably, researchers found early implantation solving this problem. Implanting the device at an early age improved speech and understanding. School aged children who implanted the device at their 18th month showed better cognitive skills compared to children who started using the hearing aid late, by the age of 28 months.

"Cochlear implants produce remarkable gains in spoken language and other neurocognitive skills, but there is a certain amount of learning and catch-up that needs to take place with children who have experienced a hearing loss prior to cochlear implantation," Dr. Kronenberger, explained. "So far, most of the interventions to help with this learning have focused on speech and language. Our findings show a need to identify and help some children in certain domains of executive functioning as well."

Researchers hoped that identifying early signs associated with these cognitive problems can help improve outcomes. "The ultimate goal of our department's research with cochlear implants has always been to influence higher-level neurocognitive functioning," Richard Miyamoto chair of the IU School of Medicine Department of Otolaryngology-Head and Neck Surgery, said. "Much of the success we have seen to date clearly relates to the brain's ability to process an incomplete signal. The current research will further assist in identifying gaps in our knowledge."

The study has been reported in in the Journal of the American Medical Association Otolaryngology—Head and Neck Surgery.

Though cochlear implants have been known to improve hearing ability, according to the Food and Drug Administration (FDA) in U.S., they also pose some risk to the user. Some of them are listed below:

  • Implanting the hearing aid can cause residual hearing or destruction of any remaining hearing in the ear
  • Development of an infection after the surgery
  • People using the implant cannot undergo medical tests like MRI imaging, ionic radiation therapy, electrical surgery, electroconvulsive therapy and neurostimulation

Apart from these, according to the agency, there hardly exists any proper data to support the safety of the device that works by stimulating the nerves directly with electrical currents.