by Dr. Lisa Klop
Dr. Lisa Klop is an audiologist and an educational specialist for Sivantos, Inc., the manufacturer of Signia hearing aids. Her areas of particular expertise include hearing assistive technology and the fitting of kids and teens.
Children with hearing loss face various challenges inside and outside the school classroom. They require less reverberation, better signal-to-noise ratios, and shorter distances from a speaker to achieve speech recognition comparable to their normal hearing peers (Crandell, 1992). While hearing aids help provide children with needed amplification, they alone cannot always overcome the noisy challenges of school environments.
The most commonly used hearing assistive devices in school setting are FM systems. They help children better understand speech by reducing distracting background noise and reverberation, using FM radio frequencies to transmit audio (e.g., a teacher’s voice) directly into the child’s hearing aids, allowing them to better hear their teachers and improve overall academic performance. The child hears their teacher’s voice at an appropriate level regardless of the physical distance between student and teacher, or other background noise.
An FM system paired with hearing aids is the most effective solution in an educational setting. However, children do not just learn from their teachers, but also from every person they come in contact with. They are growing academically, socially, and emotionally in their school environment. This means learning takes place both in and out of the traditional classroom setting.
Learning outside the classroom
School rooms are often large and noisy, making it hard for a child with hearing loss to listen and understand speech. Beyond the tradition classroom setting, kids can find themselves in a number of places filled with noise or reverberation, such as gymnasiums, cafeterias, and hallways. A student’s ability to hear and understand what is being said decreases when the background noise and/or amount of reverberation in the room increases.
Reverberation results when rooms with hard surfaces reflect sounds, causing them to blur together and making it difficult for kids with hearing loss to discern speech they want to hear from background interference. Physical education classes typically take place in a large gym ― a prime example of a reverberant space. When participating in physical activities, not only do children need to hear the teacher or coach, but also peers and teammates who could be positioned anywhere in the room. In this situation, an FM system is not a practical solution because it works best when there are only one or two speakers to be heard. Gym time is an example of when a child would have to rely on their hearing aids alone.
In addition to academics, children are also improving their social interaction skills by building relationships and establishing friendships. A child spends most of their time either at home or in school, so as they get older, interpersonal relationships become more important. Conversations with friends and peers typically take place outside of the classroom, such as the hallways in between classes and during lunch in the cafeteria. These tend to be very noisy settings due to multiple conversations going on at once, generating a lot of background chatter. Even worse, these places are filled with hard, reflective surfaces that cause reverberation and make listening to and comprehending speech even more difficult.
An FM system works well when there are only one or two designated speakers to whom the child wishes to listen or in a classroom situation where a pass around mic can be used comfortably both to help the child hear comments from other children and to keep order in the classroom by allowing only one child to talk at a time. It is not practical for most kids to ask a group of friends on the playground to pass around their FM transmitter microphone. These situations often involve conversations that flow between multiple members who join in and leave at various times. Because FM doesn’t effectively work in these social situations, hearing aid performance plays a vital role in helping a child understand and participate in group conversations.
Advanced hearing aid features are key
Unlike adults who acquire hearing loss, very young children need to develop their auditory skills first. That means they need to hear not only speech, but all sounds in their environment. Advanced features in hearing aids like directional microphones and digital noise reduction may end up taking away auditory information children need in order to learn “how to hear.” Therefore, more advanced features in hearing aids might not be appropriate for very young children whose sense of hearing is still developing.
Recent research has shown that features like directional microphones and digital noise reduction, which have been consistently beneficial to adults, can also help children around eight and older (Crukley & Scollie, 2014, Pittman & Hiipakka 2013, Ricketts & Picou, 2013). Beyond FM capabilities, parents should make sure their child’s hearing aids offer features that reduce reverberation and background noise, all while still being suitable for the lifestyle of an active child.
Today’s most advanced hearing aids feature a number of automatic directional microphone and digital noise features that highlight the target speech source, reduce reverberation, and minimize background noise. Throughout the school day, the student’s hearing aids have the ability to continuously and automatically adapt to optimize features and enhance speech understanding. They offer the ability to stream a child’s favorite music or a phone call directly in their hearing aids. Many can be remotely controlled via smartphone apps. Some of them are even eco-friendly with built-in rechargeability. They are robust, many being able to withstand an active child’s lifestyle and resist sweat and water intrusion with an IP67 or IP68 rating.
An added hearing aid feature that can be beneficial is the “speech in noise only” option in the fitting software. Hearing care professionals can select this option when adjusting a child’s hearing aids so that digital noise reduction and directional microphones are activated only when they detect both speech and noise. When speech sounds are not present, these features will not engage, allowing the child to hear all sounds in their environment. However, when speech sounds are present, these features activate to reduce background noise and ensure optimal speech understanding. This allows for a smooth transition in settings suitable for younger children until they are able to use full advanced signal processing.
Summary
It’s essential to think about a child’s hearing needs beyond the traditional classroom setting. The latest research supports that older kids can perform better using hearing aids with advanced digital features, such as noise reduction and directional microphones. In circumstances where an FM system is unrealistic, these automated hearing aid features can be helpful. These not only help kids grow academically, but also develop vital interpersonal skills.
References
Crandell, C. & Smaldino, J. (2000). Classroom acoustics for children with normal hearing and with hearing impairment. Language Speech and Hearing Services in Schools, 31, 362-370.
Crukley, J. & Scollie, S. D. (2014). The effects of digital signal processing features on children’s speech recognition and loudness perception. American Journal of Audiology, 23(1), 99-115.
Pittman, A. L. & Hiipakka, M. M. (2013). Hearing impaired children’s preference for, and performance with, four combinations of directional microphone and digital noise reduction technology. Journal of American Academy of Audiology, 24(9), 832-844.
Ricketts, T. A. & Picou, E. M. (2013). Speech recognition for bilaterally asymmetric and symmetric hearing aid microphone modes in simulated classroom environments. Ear and Hearing, 34(5), 601-609.
