Let’s explore auditory sensitivity
People with Sensory Processing Disorder (SPD) may report auditory sensitivity, auditory hypersensitivity or hypersensitivity to sound. The medical term for sound sensitivity is ‘hyperacusis’. Occupational therapists sometimes also use the term ‘over-responsivity to noise’ to describe this sensory challenge. In this post we will explore
The reasons auditory sensitivity might occur
Strategies you can use to help support individuals who experience auditory hypersensitivity
People who experience auditory sensitivity may be sensitive to certain sounds and not others. They may overreact to sounds or avoid noisy places or activities. Others might find filtering out background noise more difficult than others do.
People who have auditory hypersensitivity may also experience auditory sensory overload. This is when the brain becomes overwhelmed by the amount of sound it needs to process. The brain becomes overloaded by the amount of noise and finds it difficult to focus on other things. This includes feeling overwhelm when too many competing noises occur at once. For example, if you are trying to have a conversation in a busy café where there is music also playing. Children and adults with autism or Asperger’s frequently report auditory overload.
For those living or working with a child or adult that experiences sound sensitivity these are three things you should know.
We will start with a quick video on sound sensitivity by OT Kim Griffin
What causes auditory sensitivity?
Auditory sensitivity, or auditory hypersensitivity, to sounds can occur for a number of reasons. Sometimes the hearing sensitivity occurs because of a medical condition or structural problem within the ear itself. It can also occur as a side effect of some medications. If this is the case, then the child or adult will need to seek further support from relevant medical professionals. In this case, it would not be correct to consider the sensitivity as a sensory processing issue.
When there is no medical reason to explain the auditory sensitivity, researchers think that the brain is not processing sounds adequately. Researchers suggest that the part of the brain that receives and filters noise and sound, the amygdala, is working differently. The amygdala decides on how important noises are, which ones we should attend to and which ones to ignore. When someone experiences sensitivity to sounds, it is thought the amygdala pays more attention to sounds than it needs to. Occupational therapists usually refer to this sensory issue as a ‘sensory modulation difficulty’. Sensory modulation is one of the components of Sensory Processing Disorder (SPD). You can read more about SPD on our page, ‘What is Sensory Processing Disorder?’
Occupational therapists may label auditory sensitivity as an ‘over-responsivity to noise’. This is because children and adults with sound sensitivity usually have a bigger response or reaction to noises than might be expected by someone who does not experience auditory hypersensitivity. The child or adult might be more easily surprised or startled by sounds than others. Or, they may hear sounds that others in the same space don’t hear. They may find it difficult to ignore sounds or become quickly overwhelmed by multiple sounds. This is sometimes called auditory overload.
Auditory overload – the amygdala and its ‘fight flight freeze’ response
The amygdala is a pea sized group of neurons that sit roughly in the centre of the brain. It connects to most of the other parts of the brain and sends sensory messages from the body to the relevant parts of the brain. It is a bit like a traffic controller, sending and directing the sensory messages to the part of the brain that needs to process them. It is also responsible for keeping the body safe. Sometimes it will trigger an automatic safety response called a ‘fight, flight or freeze’ response. This response is a protective mechanism designed to keep us safe.
The amygdala is the part of the brain that makes us jump if we hear an unexpected sound. It is the part of the brain that tunes in if we hear a noise that we can’t quite locate or identify. It’s the part that makes us instantly more alert if we hear our head teacher’s or manager’s voice. It is also the part of the brain that processes sounds differently in children and adults who experience auditory sensitivity.
What is going on when there is auditory hypersensitivity?
It is thought that the amygdala (the sensory traffic controller) of children and adults with auditory sensitivity pays much more attention to sounds than expected. Instead of ignoring sounds that aren’t important, it keeps attending to them. This means children and adults with sound sensitivity are more easily distracted to noises in the environment. It can also decrease their ability to focus on the relevant noise (e.g. their teacher talking).
Children or adults with hypersensitivity to noise are also typically more easily alerted by sounds than others. Their sensory traffic controller is more alert and listening out for sounds. When an unexpected sound occurs, instead of directing the sensory messages through to the thinking parts of the brain to understand what it was, the amygdala more readily initiates a fight or flight reaction. This can also occur when someone is anxious. So, a person’s level of anxiety will also affect their level of sensitivity to noise. You might have experienced this if you have ever been walking in the dark in an unfamiliar space. Here, your senses would typically be more heightened, and you may overreact to a sound which you otherwise would not. For example, a bird singing might give you a fright.
What does auditory sensory overload feel like?
Sometimes children and adults with sensitivity to sounds experience auditory overload from the noises in their environment. Auditory overload is commonly reported in autistic spectrum disorder. The video clip below provides an example of what this might feel like.
When auditory overload occurs it is thought that the amygdala struggles to control all of the sensory traffic. It is like a traffic jam. One of those traffic jams where all of the cars are beeping their horns. The brain cannot process all of the information and will trigger a fight, flight or freeze response. So, the child or adult might hit out, run away or shut down. It is important to remember that this is an automatic nervous system response rather than ‘bad behaviour.’
Sit for a moment, close your eyes and listen. It’s likely there are sounds in your environment that your brain is ignoring. A clock ticking maybe, or computer fan. Individuals with auditory sensitivity find these every day sounds much harder to ignore.
The commonly reported signs of sound sensory issues can include
These are commonly reported signs, but you must remember every child is different so may not experience sound sensitivity in the same way. Some common signs of auditory hypersensitivity include
The child dislikes loud or unexpected sounds such as fire alarms, sirens, school bells or fireworks
They may startle easily to unexpected sounds, such as sirens or a motor cycle going past
The child may dislike higher pitched sounds, such as vacuum cleaners or hand dryers
They could have difficulty with low hum pitched sounds, such as a refrigerator or lorry engine
The child may be easily distracted by background noises, such as traffic outside, background music, an air conditioner, a refrigerator or buzz from fluorescent lights
They may notice sounds that others don’t notice
The child may cover their ears to sounds
They could dislike the cinema or concerts due to the noise level
Sensitivity in other senses
It is common for children with sound sensitivity can sometimes have sensitivity is other senses. For example, they may have tactile defensiveness, or touch sensitivity. Or, they may try to regulate by chewing or putting items in their mouth.
You can help children and adults who experience auditory sensitivity by
Firstly, you must understand that their responses are driven by the sensory traffic controller in their brain. The child’s (or adult’s) responses are not naughty or a difficult behaviour. They are having difficulty processing the sounds that they are hearing in the environment
Have ear defenders or noise cancelling headphones available for the child to use in situations that might be noisier (e.g. cafeteria, fire work event, shopping centre)
Give the child extra time between instructions and also more time before you repeat instructions to avoid auditory overload
Reduce the sound distractions in the environment when they need to work and focus, this could be by turning distractions off or using headphones
Supporting overall sensory regulation throughout the day
Where to next?
If you want to learn more about other sensory issues, we recommend our articles Signs and Symptoms of Sensory Issues and What is Tactile Defensiveness, or touch sensitivity?
To understand more about autism and sensory issues, we suggest this article ASD and Sensory Processing Disorder
If you want to learn even more, you might be interested in our online sensory processing training courses. There are three options available depending on your time and needs.
You can also read more about misophonia, another name for sound sensitivity here. The article gives a personal account of the sounds that someone with sound sensitivity might find challenging day to day.
- Ayres, A.J. (1972). SI and Learning Disorders.
- Dunn, W. (2014). Sensory Profile-2. User’s Manual. Texas: The Psychological Corporation.
- Miller, L.J. (2014). Sensational Kids Hope and Help for Children with Sensory Processing Disorder. Revised
- Mucklow, N. (2009). The Sensory Team Handboook.