Overview of Hearing Aid Fitting for Children
Many worldwide programs that screen the hearing of newborns now make it possible for us to detect hearing loss in infants just a few weeks old. If suspected by families, teachers, and medical teams, hearing loss in children that come late or are temporary due to reasons like genetics, glue ear (a condition where thick, sticky fluid collects behind the eardrum), cytomegalovirus (a common virus that can infect people of all ages), certain medicines that can damage the ear, or injury can be diagnosed quickly.
Without enough exposure to sound, children with hearing loss can lag behind others in their development of speech and language, learning through observation, and social interactions. This can further affect their self-confidence, educational achievement, and future career opportunities. When set up and used correctly, hearing aids can help reduce the differences faced by children with hearing loss compared to their peers who hear normally.
A hearing aid is a battery-operated device that magnifies sound and passes it along the hearing way, specifically to the tiny hairs within the inner ear that pick up sound vibrations. Fundamentally, it consists of a microphone to pick up sounds, an amplifier to increase their volume, and a speaker to play these sounds into the ear. It picks up sounds from around you, boosts them according to your specific hearing needs, and plays them into your ear through a suitable connection.
The two main ways hearing aids deliver sound are:
* Air conduction: These traditional hearing aids send sound via the air-conduction auditory pathway, which includes the outer, middle, and inner ear. They can be worn behind the ear or in the ear.
* Bone conduction: When the outer and/or middle ear(s) are damaged, sound delivery depends on the bone conduction pathway, which sends sound through the skull bone directly into the inner ear, skipping the outer and middle ear structures. These devices are usually worn on a stiff or soft headband. They should not be mistaken with bone-anchored hearing aids (BAHA), which are surgically implanted into the skull bone of the user, though they use the same conduction pathway.
Hearing aids available today are almost entirely digital, allowing health professionals to program a personalized sound profile for each patient according to their individual needs. They can adjust to various sound environments, like noisy classrooms; they can connect wirelessly with mobile and tablet devices and keep track of usage time.
With accurate fitting done by a seasoned health professional, hearing aids can offer children with hearing impairments valuable exposure to speech and environmental sounds, enabling them to develop on par with peers who can hear.
Anatomy and Physiology of Hearing Aid Fitting for Children
The system that allows us to hear, called the peripheral auditory system, is divided into three parts: the outer ear, middle ear, and inner ear.
The outer ear is made up of the part of the ear you can see, known as the pinna, and the ear canal, known as the external auditory meatus. The job of the outer ear is to collect sounds from the environment around us. These sounds then travel down the ear canal to the eardrum.
The middle ear contains the eardrum and three tiny bones: the malleus, incus, and stapes, which are connected to the inner ear. Our middle ear is also connected to the back of our nose by a small tube called the Eustachian tube. This tube helps to balance the pressure in our ear with the pressure outside. When sound travels into our ear, it makes the eardrum vibrate. These vibrations are then passed on to the tiny bones, and eventually to a part of the inner ear called the cochlea.
The cochlea, along with structures called semicircular canals, make up our inner ear. The inner ear helps us to understand movements of our head and speed of movement. The cochlea looks a bit like a snail shell and it is filled with fluid. Inside it, there’s a structure called the Organ of Corti that contains tiny cells shaped like hairs. These cells respond to different sound frequencies. When the last bone in our middle ear vibrates, it causes the fluid in the cochlea to move. This movement is then converted into the equivalent of electrical signals by the hair cells. These signals then travel along a nerve to the brain, where they’re interpreted as sound.
When it comes to how hearing works, we have two main pathways: air conduction and bone conduction. Air conduction is the process we just talked about, where sound travels from our outer ear, through our middle ear, to our inner ear. In bone conduction, sound vibrations can be passed directly through the bones of our skull to our inner ear. This is important in deciding the type of hearing aid that might be suitable for someone. If there are any issues with the structures of the outer or middle ear, a hearing aid that uses bone conduction might be a better option.
Why do People Need Hearing Aid Fitting for Children
If a child under 18 years old has a hearing problem that can be helped with devices, it’s recommended that they’re offered hearing aids. When deciding if a child should wear a hearing aid, doctors need to consider several things:
- The severity of hearing loss: The effectiveness of a hearing aid can depend on the working nature of inner and outer hair cells in the ears, which help transmit sounds. In some cases, severe hearing loss might be due to not having enough of these cells. In this situation, a hearing aid might not help much because it can’t amplify sound enough. Here, a cochlear implant that directly stimulates the auditory nerve might be more useful.
- The type of hearing loss: Sometimes, the hearing loss is due to a temporary problem such as fluid in the middle ear, also known as “glue ear”. In such cases, using a different kind of hearing aid, a bone conduction one, might be better because it doesn’t need to amplify sounds as much.
- The ear’s structure: If a child’s outer or middle ear hasn’t developed properly, they might have trouble hearing sounds that are amplified by a regular hearing aid. A bone conduction device could then be a better option. If a child has issues fitting a regular behind-the-ear hearing aid, accessories like toupee tape might help.
- The parent’s or older child’s motivation: Sometimes, hearing loss is hard to accept, and not everyone is ready to wear a hearing aid. If a hearing aid isn’t used properly, it might not help much. So it’s essential that doctors provide ample information and counseling to ensure that the child and their parents are comfortable with managing and benefiting from the hearing aid.
- The accuracy of the hearing test: A hearing aid is programmed based on the child’s hearing test or audiogram. If these aren’t accurate, the hearing aid might make sounds too loud or too quiet. As such, doctors must take extra care to ensure that the child’s true hearing levels are identified.
- Family’s preference for communication: Not all families prefer to have their child use a hearing aid. For example, families who primarily use sign language might feel this is the best choice for their child. It’s important that doctors respect these choices and provide the necessary support in whatever decision the family makes.
Remember, choosing to use a hearing aid is an individual decision and should be made considering all these factors. If your child needs a hearing aid, it’s advisable to seek guidance from healthcare professionals who can provide all the necessary information.
When a Person Should Avoid Hearing Aid Fitting for Children
There aren’t really any medical reasons why a child with some level of hearing loss can’t be fitted with a pediatric hearing aid, as long as tests (known as audiometry) show they can benefit from it. There might be other non-medical reasons, though, that could make it less advisable.
The main reasons are related to whether or not the child and their family are willing to use the hearing aid. Some people might choose not to use a hearing aid for various reasons. For example, they might worry about being judged by others for using one, which is called social stigma. Sometimes, the family’s wishes play a role, especially if they are part of the Deaf community and have specific views about hearing aids. At other times, the child might struggle with using the hearing aid due to difficulties with thinking, movement, or handling small objects.
Overall, the decision to use a hearing aid should be up to the child and their family, and they should not feel pressured into it if they are not interested.
Equipment used for Hearing Aid Fitting for Children
When it comes to fitting a hearing aid, there are a fair amount of tools that are necessary. These tools are properly adjusted and kept in good working condition. Here’s what is needed:
A computer installed with software that helps to fit and verify the hearing aid’s functioning is needed. Special cables for programming the hearing aid or a wireless link device are used too. Then, there is the hearing aid itself. It is chosen based on its power, size, color, and ability to connect with other devices. Some hearing aids can even connect with FM radio signals or are made in a way that kids can’t tamper with them safely.
We also use other attachments like earmolds or thin tubes for the hearing aids that you wear behind your ear.
In some cases, we might use real-ear measurements. If that’s required, we’ll need a box for testing, some tools to verify the hearing aid’s function, a tube for taking real-ear measurements, and a tube to distinguish between the real ear and coupler.
The following items may also be handy for the health care professional:
A demo hearing aid helps the family to understand visually. There will also be written instructions and information. The hearing aid often comes with a maintenance pack that includes a puffer for the tube, a checker or charger for the battery (if the hearing aid can be recharged), tablets to remove moisture, tools for cleaning, antiseptic wipes, a stetoclip, and a case for the hearing aid.
Additionally, we may use retention devices like toupee tape, clips for clothing, or loop retainers. These help to keep the hearing aid secure. We might also have materials for testing speech, cases for FM receivers that look like ‘shoes,’ ‘socks,’ or ‘boots,’ and medical tape to ensure that the tube used for real-ear measurements stays in place.
Who is needed to perform Hearing Aid Fitting for Children?
When a child needs a hearing aid, it should be fitted by a healthcare professional who has a lot of experience in this field, often an audiologist who has had extra training in pediatrics, or kids’ health. The process is similar to how adults get their hearing aids fitted, but there are some extra steps taken to make sure it fits perfectly, especially for kids who haven’t learned to talk yet or who find it hard to express how they feel about the fitting.
There should be a team of different health professionals involved in this. This team may include audiologists (hearing specialists), doctors, specialists who help kids with hearing loss learn, teachers who specialize in teaching kids who are deaf, and language therapists. These professionals should already be familiar to the child and their family by the time the hearing aid is fitted.
How is Hearing Aid Fitting for Children performed
When fitting a hearing aid for a child, specialists follow guidelines set by various health organizations such as the American Hearing Association and the British Society of Audiology. The following standard procedures are usually involved:
1. Preparing for the Fit:
Doctors enter the child’s hearing test results, along with other details like gender and date of birth, into the fitting software. This helps calculate the perfect hearing aid prescription for the child’s individual needs.
They’ll then choose the right prescription method following recommended guidelines. Different approaches, like the Desired Sensation Level (DSL) and National Acoustic Laboratories (NAL), are used. Both methods aim to enhance speech clarity while keeping sounds comfortable. They even have similar results in terms of understanding speech, however, they vary in terms of loudness and sound quality.
Once the right hearing aid is selected, it will be configured using specialized software. Specific components of the hearing aid, such as the earmould and tubing, are selected to generate the right sound level for the child.
Ahead of the visit, the doctor will prepare special measurement software and tools to ensure the hearing aid works as expected.
2. Counselling of the Family/Older Child and Orientation to the Device:
Effective counselling is essential to help the family understand how to use and care for the hearing aid. The doctor will provide important information, in both written and verbal format, about benefits, usage, controls, cleaning, and maintenance among other things.
If other hearing devices, like personal listening devices or FM systems, are required, the doctor will also provide guidance on these.
3. Verifying that the Hearing Aid Works (Validation):
Validation is a crucial step, especially for children who cannot verbally express their experience with the hearing aid. This is done by measuring how the hearing aid functions in the child’s ear using two methods: Real-ear-to-coupler difference measurements (RECDs) and Real-ear measurements (REMs).
RECDs help doctors fine-tune the hearing aid by measuring the intensity of sound from the hearing aid both in a model of the ear (coupler) and in the child’s actual ear and then comparing the measurements
REMs, on the other hand, provide real-time measurements of how the hearing aid functions in the child’s ear itself. This method is usually used for older children who can sit still for ten to fifteen minutes in a quiet room.
In both methods, the specialist aims to ensure the hearing aid works perfectly, considering how different ear sizes can impact sound intensity. For kids, getting this right is crucial to avoid overly loud sounds.
When fitting the hearing aid, ensuring that the device works correctly is a detailed process involving both practical adjustments and communication with the child and their family.
Possible Complications of Hearing Aid Fitting for Children
Hearing aids are generally safe to use without causing any clinical problems due to their non-invasive nature – meaning they don’t require any surgical procedures to be used effectively. These devices are especially useful to patients with specific conditions or physical features that might increase the risk of complications from more invasive treatments like T-tube insertion or implantable bone-anchored hearing aids.
For kids using hearing aids, the real challenge is often making sure they wear them consistently after they’ve been fitted, rather than any issues with the fitting process itself.
Healthcare professionals play an essential role. They provide the right advice to family before fitting the hearing aids, help to manage the device, and offer support after fitting to ensure the hearing aids work effectively. The use of hearing aids can be tracked through data-logging records in the weeks and months after fitting. This helps to check whether the patient is using them as advised, and whether any adjustments or further guidance is needed.
What Else Should I Know About Hearing Aid Fitting for Children?
Technology of digital hearing aids, along with the practice of screening the hearing of newborns across the globe, have played a big part in lessening the lifelong impact of hearing loss in children. When experts follow local and national guidance in using hearing aids, they can better children’s language skills, education, and mental and social wellbeing.
