As a paediatric audiologist and father of two young daughter, sound is often on my mind. Like most parents, knowing how to manage the soundscape of life can be tricky. I remember when my first child was young, she would often get upset by the sound of hand-drying machines in public toilets. This was for her a ‘trigger sound’ and would often evoke a strong emotional response.

We will look at this example a little more later but first we will take a step-back and explore what noise sensitivity is, why some populations are more likely to experience noise sensitivity, how this can be related to a more general sensory sensitivity and finally, how technology can help support children who often find the sounds of life a little too much.

What is noise sensitivity?

In the audiology world, there are several important definitions to consider. Hyperacusis and misophonia have been used to describe negative reactions to sound for some time. A more recent addition of noise sensitivity has been added, and we will explore all these terms below.

Hyperacusis:

This generally describes physical discomfort when any type of sound reaches a certain level of loudness that would be tolerable for most people. Think of going to the cinema with sounds of 80 decibels or more, or the sound of a lawnmower, again over 80 decibels. If these sounds are too loud for someone, the person may have some degree of hyperacusis, as most people would be ok with these sounds.

Misophonia:

This refers to intense emotional reactions to certain sounds (often sounds such as chewing and sniffing) that are not influenced by the loudness of those sounds. Imagine being sat on a train and a person opposite is noisily eating their food. For most people, not a problem, for some, the worst experience possible!

Noise sensitivity:

This refers to a general reactiveness to all sounds regardless of how loud they are perceived or how loud they actually are. Imagine sitting in your living room trying to work, a neighbour is cutting their hedges, which is making some noise, not too loud, but clearly heard. A noise sensitive person would find this sound disruptive, and their nervous system would become activated, leading to a cascade of emotions. It would be almost impossible for this person to feel at ease.

Why are some people affected more by sounds?

Whilst there are some differing theories on why sound is more troublesome for some people, we have to recognise that hearing involves the ears, the pathways from the ears to the brain and the brain itself.

The ears are the receptors of sound, the pathways are responsible for transmitting and to some extent processing the sounds, and the brain makes sense of these sounds at the same time as connecting to other parts of the brain which are responsible for emotions and feelings.

There is some evidence that some brains struggle to filter out unimportant sounds (think neighbour cutting their hedges, or people talking in a café). Whereas for other brains, these sounds are barely noticed. Also, that for some people, their brain’s emotional centres are more deeply tiggered by sounds, which leads to overwhelm, anxiety and shutdown.

Noise sensitivity as part of a more general sensory sensitivity

If you have ever felt like your nervous system is firing on all cylinders, amplifying every sensation around you, then you have some idea of how our senses can lead to overwhelm. Imagine being a small child in a shopping mall. Everything is bright, there are people and sounds all around. Music, laughter, talking and so much visual stimulation with people moving, bright lights everywhere, shop fronts designed to attract attention.

For some, this bombardment of the senses can lead to a general sensory overload of which noise is just one component.

What is sensory overload?

Our brains are complex and contain millions of neural pathways that are constantly trying to make sense of our external and internal world.

When the brain is unable to process all these inputs or make sense of all these inputs, this can result in sensory overload. Sensory overload happens when our brains are overwhelmed by too much sensory input, such as sights, sounds, smells, tastes, and touch. Think of these as triggers to the nervous system.

When sensory overload occurs, our nervous system becomes bombarded by a surplus of sensory information, disrupting its delicate balance. It’s as if the volume dial on our senses is cranked up to the maximum, flooding our brains with overwhelming stimuli.

Symptoms of sensory overload

Sensory overload can show up differently in each person. Some common experiences include irritability, restlessness, anxiety, difficult concentrating, physical discomfort (increased heart rate, tightness in the chest), panic and paralysis and often for children meltdowns or shutdowns.

Adults and children alike can become dysregulated and irrational, and these symptoms are the body’s way of reacting to an overwhelming sensory experience.

For a young child experiencing these intense feelings, it is no wonder that they need strategies and support to help manage these challenging situations.

Why might my child experience noise sensitivity?

We know that children who are neurodivergent are far more likely to experience sensory overwhelm. Neurodivergent conditions can overlap but generally include autism or autistic spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), dyslexia, auditory processing disorder (APD) and sensory processing disorder (SPD).

It is estimated that around 15-20% of the population (1 in 7) is neurodivergent with some estimates of ASD to be 1 in 31 children (USA data).

One of the main reasons for increased sound sensitivity in these populations is how the brain processes information. Research is ongoing but for now simply being aware of this increased risk of noise sensitivity is useful.

For parents of children with ASD, this general sensory sensitivity will be all too familiar. The mornings when every pair of socks is not right, or the day when every newly bought t-shirt is just too scratchy or the seams are too thick!

Thankfully for noise sensitivity and the particular sounds that may trigger overwhelm, there are some strategies to help parents. One of the most useful is the use of headphones, in particular active noise cancelling headphones.

Active Noise Cancelling (ANC) Headphones

It can be difficult as a parent to know how to support a child with noise sensitivity. In my experience as a paediatric audiologist, I would caution against limiting sound too much. There is a delicate balance between on the one hand, providing a child with tools to prevent overwhelm, and on the other, limiting sound too much so that a child lives in a ‘quiet world’ which can lead to even more problems.

This is where active noise cancelling headphones can prove really valuable. This type of headphone has been used for some time but more recently has been included in children’s headphones.

How does Active Noise Cancelling (ANC) work?

Unlike conventional hearing protection which simply block out sound, ANC uses small microphones built into the headphones alongside some clever signal processing.

In simple terms, the headphones listen to external sounds (like traffic or air-conditioning noise). They then create a sound wave that is the exact opposite (called ‘anti-noise’). The original noise mixes with this anti-noise to combine and cancel each other out. This sounds advanced but actually is based on a simple principle in physics called destructive interference.

The benefit of this technology is two-fold.

Firstly, if a child is using their noise-cancelling headphones to listen to music when in noisy environments, they are able to hear their music at a much quieter level. This is safer and less likely to overwhelm them.

Secondly, they are protected from many of the troubling and potentially overwhelming sounds in the environments that they are in. Again, this reduces the likelihood that the environment will overwhelm them.

This reduction in auditory triggers can reduce the likelihood of sensory overload and make life that much more enjoyable.

Back to the hand-driers

We started with the example of the hand-driers being an auditory trigger for one of my children. I am sure this is a common experience for many parents and there are many reasons for children to react this way.

The sound from these hand-driers is generally quite loud. But for children, being smaller than adults, their heads and ears are often just at the right height to hear the sound even louder than an adult would. Imagine putting your head right next to a hand-drier!

Another reason this particular sound can be problematic, is the type of sound it is. Hand-driers typically produce sounds containing lots of different frequencies, which makes their sound not only loud but a bit unpleasant. If you wanted to relax, I am pretty sure you wouldn’t choose a hand-drier sound to sooth you to sleep!

Here is one example of where active noise cancelling headphones could help. The headphones will detect the noise, create an anti-noise and thus less likely overwhelm a child.

Take-away advice

• Children with and without neurodivergent conditions can easily be overwhelmed by sounds.
• Neurodivergent children are much more likely to be negatively affected by sounds.
• Technology such as active noise cancelling headphones, when used sensibly can form one part of a sensory plan to help children manage daily life with confidence.