Children with hearing loss have reduced access to speech, even when they use hearing aids. Remote microphone systems can improve auditory access. Can they also improve language outcomes for children?
To learn spoken language, children need full access to speech input from caregivers. Previous studies show that children who are exposed to more words have stronger language outcomes than children who are exposed to fewer words. For young children with hearing loss, the quantity of language access from caregivers will be reduced as a result of the hearing loss, even in cases of mild or moderate degrees of hearing loss. Our starting point for audiologic intervention is usually early provision of well-fit hearing aids. Unfortunately, there are limitations with the amount of access hearing aids can provide. These limitations occur when listening in background noise or when the caregiver is at a distance from the child. As infants begin crawling and eventually walking, they will encounter more challenging listening situations in which they don’t have clear access to speech input.
Another type of hearing technology that is available to families is a remote microphone system. This technology increases the intensity of speech, even in noisy or distant listening situations, because the caregiver wears a microphone which transmits the speech signal directly to the hearing aids of the child. This use of a remote microphone can result in a 15 dB increase in the loudness of the speech input. The limitations of remote microphone systems include more equipment for caregivers to deal with and additional cost. In light of these limitations, an important clinical question arises: does use of remote microphone systems at home lead to better language outcomes in children, as opposed to only using hearing aids?
Examining the impact of remote microphone systems at home
The Outcomes of Children with Hearing Loss (OCHL) study seeks to examine the effects of hearing loss on development. As part of our ten-year research study, we have investigated the use of remote microphone systems at home for children who are hard of hearing. This investigation includes efforts to reduce gaps in our knowledge about remote microphone systems. In our study, we tested preschoolers with hearing loss who had access to hearing aids and remote microphones at home and compared their performance to a closely matched comparison group of children with hearing aids and no remote microphone systems at home. At age 5 years, children completed a battery of language tests, including vocabulary, grammar, and discourse measures. The discourse measure assesses higher-level language skills, such as the ability to integrate multiple concepts, respond to subtle directions, or make predictions (for example, “What will happen to the cookies when we put them in the oven?”).
Our analysis indicated no differences between the children with and without remote microphones on the vocabulary and grammar tests; however, children with remote microphones showed significantly higher scores on the discourse test. These preliminary results suggest that remote microphone systems, in combination with hearing aids, increase access to distant speech and exposure to caregiver input, which might have a positive impact on higher-level language skills.
What does this mean for a child with hearing loss?
With improved higher level language skills, children are better able to problem solve, predict outcomes, and justify their answers, which are all skills that promote success in the classroom and help them in their daily social lives.
For more information on the OCHL team’s investigations into remote microphone systems, refer to our newly published articles that have been published in the Journal of Speech, Language, Hearing Research and the International Journal of Audiology.
And to learn more about the OCHL study, please visit our website.
Contributors from OCHL study:
Beth Walker, PhD, CCC-A/SLP
Dr. Walker is an assistant professor in the Department of Communication Sciences and Disorders at the University of Iowa and the Director of the Pediatric Audiology Laboratory. Her NIH-funded research focuses on pediatric aural habilitation. She is an investigator on the Outcomes of Children with Hearing Loss study.
Maura Curran, PhD, CCC-SLP
Dr. Curran is a postdoctoral researcher/research SLP in the Department of Communication Sciences and Disorders at the University of Delaware. Her research focuses on grammar intervention and academic outcomes for children with language disorder.