Children’s Hearing
Hearing Loss in Children
How do we Hear?
There are 3 main parts of our hearing system; the outer ear, middle ear and inner ear.
Outer Ear:
Our outer ear is the part we see. It is made up of the pinna and the ear canal that directs the sounds we hear down to our middle ear. The shape of the pinna plays an important role in helping us locate where sounds are coming from, and to focus and attend to the person talking in front of us.
The outer part of our ear canal is lined with tiny hairs that assist in making wax. Wax is important to protect our ear from anything entering it. Cotton buds are not recommended to clean our ears as they damage these delicate hairs and our ears’ natural cleaning process. Wax is only a problem if it completely blocks the ear canal.
Middle Ear:
Our middle ear includes the eardrum (tympanic membrane) and the ossicles (the 3 smallest bones in the body, the malleus, incus, and stapes). Sound enters our ear canal from our outer ear, vibrates our eardrum which in turn vibrates our ossicles. High pitch sounds cause fast vibrations and low pitch sounds cause slow vibrations.
The ossicles are in the perfect position to increase the energy of sounds we hear, prior to them entering our inner ear. Our inner ear is filled with fluid and without this increase in energy, sound vibrations would be significantly reduced going from air to fluid (e.g., we need to more energy walking through water at the beach (fluid) than walking on the sand (air)).
Inner Ear:
Our inner ear is made up of the cochlea and semi-circular canals. The cochlea is about the size of a pea and shaped like a small shell. It is responsible for converting sound vibrations from the middle ear into electrical impulses (neural signals) that are sent along the auditory nerve to our brain. Inside our cochlea are approximately 15,000 delicate hair cells (3,500 inner hair cells and 12,000 outer hair cells). The inner hair cells do most of the work sending signals to our brain, however the outer hair cells are important to help the inner hair cells to process soft sounds.
When sound vibrations enter our cochlea, a wave of fluid moves over our inner ear hair cells, bending them back and forth and triggering an electrical (neural) impulse. The hair cells are positioned precisely to represent different pitches. The fluid wave has the most energy at the pitch we need to hear. The neural impulse travels up our auditory nerve to our brain (auditory cortex). When sounds reach our brain, our past experiences, knowledge, and memory make sense of what we have heard.
Our semi-circular canals are made up of three tiny, fluid filled tubes, each positioned at a different angle to help us balance. When we move our head, the fluid inside these hair cell lined tubes also moves, bending the hair cells back and forth. This causes a neural impulse to be sent to our brain with information about our position and what we need to do to stay balanced. If we spin around and then suddenly stop, we feel dizzy as it takes the moving fluid a little longer to stop.
What are the Types and Causes of Hearing Loss?
It is estimated that 1 in 6 Australians have some degree of hearing loss. Further, research suggests that approximately 1 in 1000 children have hearing loss at birth. A further 1 in 1000 are not detected until school age, i.e., the number of children with hearing loss doubles by school age (Hearing Australia, 2014). For infants diagnosed at birth, approximately 50% have no risk factors for hearing loss and the cause remains unknown.
Undetected hearing loss can have a significant effect on a child’s development (i.e., their speech& language, social skills, behaviour, and academic progress). Detecting hearing loss early is important to make sure your child is supported and has every opportunity to reach their full potential.
Damage to any of the three parts of our ear can cause hearing loss.
Hearing loss is described using:
- where the issue occurs (i.e., outer, middle, or inner ear)
- whether one or both ears are affected (unilateral or bilateral)
- when the loss occurred – i.e., present at birth (congenital), progressive, or acquired (e.g., illness, medication, injury).
- degree (level) of hearing loss (mild, moderate, severe, or profound)
Sensorineural Hearing Loss (SNHL)
Occurs in the inner ear and is permanent in nature. Causes may include:- Complications at birth, (including prematurity, low birth weight)
- Family history of hearing loss / genetics (most common Connexin 26)
- Frequent middle ear infections
- Infections such as meningitis or cytomegalovirus (CMV)
- Syndromes (e.g., CHARGE)
- Chronic noise exposure
- Age-related progressive loss
Conductive Hearing Loss (CHL)
Occurs in the middle ear or ear canal and may be either temporary or permanent depending on the cause. Causes may include:- Ear infections or middle ear fluid (often referred to as glue ear)
- Wax impaction (wax completely blocking the outer ear canal)
- Damage or stiffening of the ossicles (middle ear bones)
- Cyst in the middle ear (cholesteatoma)
- Bony growth along the ear canal (exostoses, often referred to as swimmer’s ears)
Mixed Hearing Loss
Occurs when there is a combination of middle ear and inner ear pathology. These losses typically require both medical and audiological management.What are the Degrees of Hearing loss?
Hearing loss can be described as within normal limits, mild, moderate, severe, or profound. The softest sounds your child can hear are measured and marked on a graph, called an audiogram. From left to right across the graph represents low pitch (125Hz) to high pitch (8000Hz) sounds (frequencies) and from the top of the graph (-10dB) to the bottom of the graph (120dB) represents the softest to loudest sounds.
Mild Hearing Loss
If your child has a mild hearing loss (between 21dB and 40dB), they may;- miss soft speech or speech at a distance
- often ask others to repeat information
- have difficulty following conversations, particularly in the presence of background noise
- tire quickly – listening is challenging
- benefit from hearing aids or the use of a personal listening device (remote microphone)
Moderate Hearing Loss
If your child has a moderate hearing loss (between 40dB and 60dB), they will;- have increasing difficulty understanding normal level conversations
- be unable to hear some speech sounds
- struggle listening in groups and in noisy environments
- tire quickly – listening is challenging
- need to wear hearing aids to access speech
- likely benefit from the use of a personal listening device (remote microphone)
Severe Hearing Loss
If your child has a severe hearing loss (between 60dB and 80dB), they will;- be unable to hear others speaking at normal conversation levels
- struggle to hear in all listening environments without the use of hearing aids
- tire quickly – listening is challenging
- have difficulty hearing in the presence of background noise, or at a distance, even when using hearing aids
- benefit from the use of a personal listening device (remote microphone) remote microphone
Profound Hearing Loss
If your child has a profound hearing loss (hearing levels > greater than 80dB), they will- not hear others speaking at loud conversation levels
- heavily rely on visual information
- have hearing and listening difficulties, especially in noise, over distance and in groups even when using hearing aids
Hearing Assessments for Children
At Little Allied Health we offer:
- Hearing screening and counselling for infants under 6 months of age (this is to support families in liaison with the newborn hearing screening program).
- Comprehensive hearing assessments from 6 months of age.
How your child’s hearing is assessed depends on their age, and their ability to respond (i.e., developmental age). Hearing assessments are FUN and non-invasive. You will quickly see why we love what we do!
When should my child’s hearing be assessed?
When should my child’s hearing be assessed?
Hearing loss is ‘invisible’ – therefore, while your child may respond well to many sounds, they may be having difficulty hearing soft sounds (e.g., sounds like ‘s’ and ‘f’ are soft sounds). Hearing can change and there is the potential for newborn hearing screening to miss a mild hearing loss.
Your child would benefit from having their hearing formally assessed if:
- there are concerns regarding your child’s speech and language development.
- your child has had several ear infections (i.e., often referred to as glue ear).
- your child watches people’s faces closely and asks for information to be repeated.
- your child often turns the television or radio up.
- your child is less responsive to sounds and appears to ignore you.
- there are concerns at school or home regarding your child’s listening behaviour and their academic progress.
- your child is clumsy or has balance difficulties.
- your child has had a head injury.
- there is a history of hearing loss in your family.
How will I know if my baby has hearing loss?
Early identification of hearing loss, and implementation of appropriate supports, is critical in ensuring your child has the opportunity to reach their full potential.
South Australia’s Universal Neonatal Hearing Screening program was introduced in 2004/2005, with most babies having their hearing screened within their first few days of life. This has dramatically reduced the age at which children with a significant hearing loss are diagnosed. However, newborn hearing screening is not a comprehensive hearing assessment and there is the potential for a mild hearing loss to be missed. Hearing can also change and monitoring your child’s hearing is important.
The following is a guide on signs to look for to ensure your child’s hearing is developing as expected for their age:
Birth to 3 months
- startle to loud sounds (body movement, eye-blink, increase or decrease in sucking)
- react to sounds other than voices in the environment
- moves eyes or head towards sound
- knows parents’ voices and calm
3 months to 6 months
- settles to familiar voices
- responds using different facial expressions when talked to
- responds to music or sound-making toys
- vocalising in response to sound
- starting to recognise own name
- localising sounds by turning head to either side
6 months to 12 months - turns head to either side and up and down to locate sounds
- appears to listen when spoken to
- responds to softer sounds
- responds to “no” most of the time when said with a firm tone
- responds to music (may sway from side to side, move arms, legs)
- understands some frequently used words (e.g., family member names, bye-bye etc.)
- increased vocalisation and may have said the first word
12 months to 18 months
- immediately responds to own name
- shows interest in environmental sounds and seeks out the source
- responds to familiar tunes
- identifies familiar things when asked (e.g., shoes)
- increasing number of spoken words
- points to things to answer simple questions (e.g., where’s your nose?)
18 months to 2 years - rapid increase in vocabulary
- starting to link 2 – 3 words
- able to follow simple directions (e.g., give the book to daddy)
18 months to 2 years
- rapid increase in vocabulary
- starting to link 2 – 3 words
- able to follow simple directions (e.g., give the book to daddy)
Please see Speech and Language Milestones for further information
How will my child’s hearing be assessed?
At Little Allied Health we offer:
- Hearing screening and counselling for infants under 6 months of age (this is to support families in liaison with the newborn hearing screening program).
- Comprehensive hearing assessments from 6 months of age.
How your child’s hearing is assessed depends on their age, and their ability to respond (i.e., developmental age). Hearing assessments are FUN and non-invasive. You will quickly see why we love what we do!
Our comprehensive paediatric hearing assessments include assessment of:
- your child’s middle ear health
- your child’s inner ear (cochlea) function
- your child’s hearing levels using age-appropriate listening games
- your child’s ability to discriminate between subtle differences in speech sounds (speech discrimination) where developmentally appropriate
Our equipment is state-of-the-art, ensuring accurate and reliable results. Our test rooms are friendly, inviting and are sound treated to comply with Australian Standards.
Play Audiometry & Visual Reinforcement Audiometry
For children 2 years to 5 years of age Play Audiometry will primarily be used to determine their hearing levels. Here your child may respond to sounds played under headphones by playing fun games like building towers with pegs, putting together a Mr. Potato Head or completing a jigsaw puzzle.
Younger children (7 months to 2 years of age) often require sounds to be presented through a small speaker positioned to the either side of your child. Here your child will be taught to respond by turning towards the sound where they will be rewarded with an animated toy. This is called Visual Reinforcement Audiometry.
Children thoroughly enjoy both assessments (as do their audiologist!).
Pure-tone Audiometry
Children > 5 years of age are generally happy to press a button when they hear a sound under headphones. Occasionally they may be encouraged to participate by having a competition with their audiologist.
Middle Ear Health
To determine your child’s middle ear health a small probe will be gently placed in your child’s ear canal for approximately 10 seconds. A gentle puff of air is presented via the probe to measure your child’s eardrum movement and position. Generally, children enjoy holding the hand-held computer which analyses middle ear status and watching “their ear draw a picture”.
If your child has been found to have a hearing loss, results from this assessment will help to determine where the problem may be located within their hearing system.
Speech Discrimination
Speech discrimination tests are also selected based on your child’s age and developmental abilities. Older children may repeat words they hear under headphones, while younger children may identify pictures or toys with their audiologist testing varying levels of their own voice.
Other tests
On occasion additional tests may be performed or recommended by your child’s audiologist.
Your Child’s Hearing Results
The results from your child’s hearing assessment will be discussed in detail during your child’s appointment. You are encouraged to ask questions regarding any aspect of your child’s assessment. On occasion, more than one session may be required to obtain a complete picture of your child’s hearing abilities. We will discuss this with you if it is required.
Comprehensive written reports are provided for all assessments and with your permission copies are sent to your child’s General Practitioner (GP) and where applicable other professionals involved in your child’s care.
Our paediatric audiologists work within our multidisciplinary team to ensure your child’s hearing needs and communication goals are supported by gold standard evidenced based practice. We value diversity and recognise the strengths of every child and family.
If your child is found to have a hearing loss, management will depend on the type and degree of their loss. We will support you and your family every step of the way in accessing the right medical and allied health support. Should your child require a hearing device, we work collaboratively with
Hearing Australia who are funded by the Australian Government Hearing Services Program to provide and fit hearing devices to eligible children and young adults under the age of 26 years at no cost.
Hearing Australia have recently launched their updated resource for parents and families on childhood hearing loss – Choices. This resource provides valuable information to help families make informed choices about the management of their child’s hearing loss.
Hearing Protection for Children
Teaching children how to protect their hearing is important from a young age. Noise-induced hearing loss is cumulative. It can also occur instantly if the noise is loud enough. You can help protect your child’s hearing by:
- Have your child use ear protection
- Reducing your child’s exposure to noise
- Set limits on your child’s use of headphones (if you can hear what they are listening to, it is too loud!)
- Have your child use noise cancelling headphones to reduce background noise making listening easier at lower volume levels
- limit the volume level from your child device where possible
- Model hearing protection by using ear protection yourself
Hearing Protection Options
Babies aged 0-18 months: Ems for Kids use a soft adjustable headband, are safe to wear from birth and are designed to make sure pressure is dispersed evenly, protecting even the littlest of ears. BABY earmuffs will grow with your child until approximately 18 months of age.
Children from 2 years of age
Ems for Kids are also available for your child up until their mid-teens. These ear muffs are perfect for use at live sport, concerts, around big noise and the fireworks. They are designed in Australia and tested to global safety standards.
An alternative brand is Alpine Muffy, which is also recommended by Hearing Australia.
At Little Allied Health we are also able to make Custom Ear Protection for your child; this includes noise protection, swim plugs and musician ear plugs. A custom product has a major advantage over universal products in that it fits your child’s ear perfectly.
How do you make a custom ear plug?
A short appointment is required to take an impression of your child’s ear to make custom ear plugs. This procedure involves placing a small foam tip in your child’s ear canal followed by a “putty-like” material which replicates your child’s unique ear shape. The material sets in approximately 3-5 minutes and is easily removed. Impressions are then sent to the manufacturer where they are scanned into computer programs and modified to make the perfect noise, sleep, or music attenuation plug for your child.
Noise protection ear plugs can reduce noise by up to 40dB. These earplugs are designed for those who frequent environments with a high level of background noise. Typically ear muffs are preferred by children, however teenagers may prefer a more discreet option.
Custom earplugs for swimming are recommended for those with grommets, eardrum perforations, or infection of the ear canal/middle ear. For those with a grommet or perforation in their ear drum, bacteria can enter the middle ear space when exposed to water. These moulds are designed to provide a comfortable but tight fit to prevent water from entering the ear canal. Thankfully, the plugs float to prevent loss.
For our budding musicians, ear protection is important to reduce sound levels evenly across all pitches to preserve clarity. Musicians are often exposed to loud levels of sound, and often for long periods of time. They need to protect their hearing whilst making sure that they can hear their own instrument / voice well.
