Hyperacusis & misophonia
While hyperacusis and misophonia can occur concurrently, the nature of the threat from these sounds is different so they are separate and distinctly different conditions. Both conditions involve an abnormal perception of loudness and awareness of intolerable sounds, and distress following exposure to these sounds.
Both conditions have the potential to escalate, so that an increasing range of sounds become intolerable.
What is hyperacusis?
Hyperacusis is an abnormal intolerance, a heightened sense of volume and physical discomfort from ordinary, everyday sounds, which other people can tolerate well. Sounds that are typically difficult to tolerate are loud/impact/sustained sounds, particularly if they are unexpected or in close proximity. High frequency (pitch) sounds tend to be tolerated less well. Hyperacusis can be a consequence of a conscious and/or subconscious sense of threat that those sounds will exacerbate pre-existing aural symptoms such as tinnitus, hearing loss or are potentially damaging.
What can cause hyperacusis?
Pre-existing tinnitus, misophonia and high levels of anxiety are factors that can predispose towards the development of hyperacusis. Hyperacusis may develop with a number of conditions affecting the auditory pathway (including acoustic shock disorder, Meniere's Disease, otosclerosis, perilymph fistula, Bell's Palsy), psychiatric disorders, neurological injuries and disorders (including head injury, migraine), adverse reactions to some medications, autistic spectrum disorders, chronic fatigue syndrome, fibromyalgia and Lyme Disease.
How common is hyperacusis?
Estimates of hyperacusis prevalence are affected by the way hyperacusis is defined and opinions range widely. Hyperacusis is less common than tinnitus, with tinnitus severely affecting 2% of the population. The consensus is that about 40% of people with troublesome tinnitus have some degree of hyperacusis.
How does hyperacusis develop?
When hyperacusis develops, everyday sounds, particularly loud/sudden/unexpected sounds, begin to appear unnaturally prominent and increasingly louder. Following exposure to some or many of these sounds, a temporary increase in tinnitus (if present) and/or hyperacusis may be noticed, and escalating sensations in the ear may develop, such as pain, a fluttering sensation or an intermittent fullness. As a result, people may come to believe that their ears are no longer able to physically tolerate these sounds or that these sounds are causing damage to their ears or hearing and should be avoided. An involuntary threat response towards these sounds and escalating anxiety about the effects of exposure to them can generalise, so that more and more sounds become perceived as intolerable.
What is misophonia?
Misophonia is a strongly aversive response to certain specific sounds, irrespective of their volume and often made by other people. Sounds that are difficult to tolerate trigger high levels of annoyance, disgust and anger. These typically include: the sounds of other people eating / breathing / swallowing / sniffing etc, repetitive sounds (eg a pen tapping, keyboard tapping), neighbour’s music, dogs barking, noise from a nearby factory etc. Misophonia can develop when those sounds become perceived, at both a conscious and subconscious level, as an intolerable intrusion into one’s sense of personal space.
How common is misophonia?
Misophonia is a relatively recently identified condition, with no prevalence data currently available. Online forums in the last few years have raised awareness, suggesting misophonia is more widespread than has previously been acknowledged.
How does misophonia develop?
Misophonia often stems from an aversive reaction to specific sounds made by family members and/or environmental sounds in childhood or teenage years. When misophonia develops, everyday sounds begin to appear unnaturally prominent and increasingly annoying. Following exposure to some or many of these sounds, high levels of irritability, anger and disgust can develop. This reaction can escalate to an involuntary rage following exposure, and can generalise to include more and more sounds. Those affected can feel overwhelmed or embarrassed by the intensity of these emotions and fear their ability to control them, or resent being exposed to their trigger sounds.
How does hyperacusis and misophonia affect people?
Hyperacusis and misophonia can range from mild to severe to extreme.
Avoidance of intolerable sounds can have a major impact on the lives of people with significant hyperacusis and misophonia, severely limiting their horizons and creating high levels of anxiety and distress.
People with hyperacusis and/or misophonia often feel the need to regularly and sometimes constantly monitor their auditory environment to anticipate and avoid intolerable sounds. Hypervigilance of the acoustic environment enhances the sense of threat from these sounds, and results in cognitive distraction and reduced concentration. In people with hyperacusis, frequent monitoring of the ear symptoms described above is common, and they may feel a need to protect their ears or sense of hearing from exposure to these sounds. In both conditions, they are likely to want to limit the high levels of emotional reaction they feel following exposure. Significant hyperacusis and misophonia can therefore be considered as "attention" disorders.
There is little understanding of hyperacusis and/or misophonia in the community. Hyperacusis, misophonia and any physical symptoms in and around the ear following exposure to intolerable sounds are involuntary and subjective. The unusual cluster of these symptoms is readily misunderstood or not believed. Explaining such an abnormal reaction to sound to other people, including at times health professionals, is difficult and clients with hyperacusis and/or misophonia often feel misunderstood, isolated or trivialised.
How is the brain involved in the development of hyperacusis and misophonia?
P Jastreboff's neurophysiological model of tinnitus and hyperacusis / misophonia: As part of the processing of sound in the brain, all sounds are evaluated subconsciously with regard to their meaning or importance to us. Sounds that are considered important (in either a positive or negative way) will be transmitted to the more conscious parts of our brain, while unimportant sounds remain "half heard".
If a sound acquires a negative association, the limbic system in the brain becomes activated, inducing fear or irritation. The autonomic nervous system also becomes activated, provoking the "fight or flight" reaction. A conditioned response develops so that repetition of this sound enhances the activation of the limbic and autonomic systems. In people with significant hyperacusis / misophonia, many sounds are evaluated in the subconscious as potentially threatening. For those with hyperacusis, this can lead to the development of tonic tensor tympani syndrome (TTTS) symptoms from a subconscious 'need to protect' the ear.
Our brain is a highly plastic organ, constantly reorganising and developing new neural connections. This means that we are able to retrain our brain to reverse the process which has led to hyperacusis and misophonia. Complete desensitisation may be difficult to achieve and an unrealistic expectation. However, partial desensitisation can make a big difference to the emotional impact and lifestyle constraints of hyperacusis / misophonia.
Tonic Tensor Tympani Syndrome (TTTS)
In the middle ear, the tensor tympani muscle and the stapedial muscle contract to tighten the middle ear bones (the ossicles) as a reaction to loud, potentially damaging sounds. This provides protection to the inner ear from these loud sounds.
In many people with tinnitus, particularly if they have developed hyperacusis, an increased, involuntary activity can develop in the tensor tympani muscle in the middle ear as part of a protective and startle response to some sounds. This lowered reflex threshold for tensor tympani contraction is activated by the perception/anticipation of sudden, unexpected, loud sound, and is called tonic tensor tympani syndrome (TTTS). This response can then generalise to other types of sound and to lower sound volume levels, resulting in the development as well as the potential escalation of hyperacusis. In some people with hyperacusis, it appears that the tensor tympani muscle can contract just by thinking about a loud sound.
TTTS typically does not develop in people with misophonia.
Following exposure to intolerable sounds, this heightened contraction of the tensor tympani muscle can:
- affect the opening of the Eustachian tube, which ventilates the middle ear cavity, and is normally closed but opens when we yawn or swallow
- tighten the ear drum
- stiffen the middle ear bones (ossicles)
- lead to irritability of the trigeminal nerve
As a result, TTTS can cause a range of symptoms in and around the ear(s). These include: pain, numbness and burning sensations in and around the ear; pain in the jaw joint and down the neck; the development of tinnitus or an increase in pre-existing tinnitus; a clicking / fluttering sensation in the ear; a sensation of blockage, fullness or frequent "popping" in the ear; unsteadiness; muffled hearing.
It is important for people with hyperacusis to accept and understand the neurophysiological basis of TTTS, which is responsible for many of the physical sensations experience in their ears after exposure to an intolerable sound.
It does not harm the ear to experience TTTS, and even though the TTTS symptoms can seem as if the ear is being damaged by some sounds, this is not the case. Moderate, everyday sounds are safe and do not harm the ear or cause a hearing loss.
TTTS-like symptoms may be due to middle or inner ear pathology, and medical investigation should be carried out to exclude this possibility. Conversely, TTTS symptoms in people with hyperacusis can be mistakenly diagnosed as due to middle/inner ear pathology or jaw joint dysfunction or temporomandibular disorder (TMD).
It is therefore important for people with tinnitus and hyperacusis who experience these symptoms to consult an Ear, Nose and Throat Specialist/TMD Specialist to ensure there is no underlying medical condition causing them.
As TTTS develops from the way intolerable sound is perceived in the brain, using strategies aiming for tinnitus habituation and hyperacusis desensitisation will help reduce TTTS symptoms. Individual guidance from a physiotherapist for relaxing the facial muscles in and around the ear, as well as identification and massage of any muscular trigger points in the shoulder and neck, can be of benefit.
Our hyperacusis and misophonia program
We provide a unique, individualised program to assist you in achieving increased tolerance to everyday sound, utilising Ms Myriam Westcott's experience and research in hyperacusis and misophonia therapy.
A detailed description of the peripheral (the outer, middle and inner ear) and central (the brain) auditory pathway is essential to understand how hyperacusis and/or misophonia develops.
Our program involves:
- an evaluation of your hyperacusis and/or misophonia and its impact on you.
- providing a detailed understanding about the development of your hyperacusis and/or misophonia.
- a personalised explanation of the peripheral and central auditory system, including the neurophysiological basis of hyperacusis/misophonia and TTTS (if symptoms are present).
- a hyperacusis/misophonia therapy program.
Practical self-managed strategies to assist hyperacusis/misophonia desensitisation and reduce auditory hypervigilance, personalised to suit each person's individual coping style, are developed. Sound enrichment and low level sound therapy are required as part of the desensitisation process.
Counselling is provided to help you:
- identify how and why sounds changed from being tolerable to intolerable, so the process can be 'unravelled'.
- recognise and gently challenge any maladaptive or destructive thought processes and beliefs , which will exacerbate hyperacusis/misophonia, by understanding and accepting the way the brain highlights threatening sounds. Examples of maladaptive beliefs: "my ears must be more sensitive than other people's because I can hear these sounds more strongly"; "intolerable sounds hurt / increase my tinnitus so they must be damaging my ears" "my ears must be more sensitive than other people's because I've got tinnitus / noise damage already"; "I can't lead a normal life because I have to avoid noisy places / music".
- learn the skill of reducing environmental scanning or hypervigilance to sounds around you.
- learn to recognise and control the emotional reaction you experience following exposure to an intolerable sound eg panic, anxiety, distress, anger, intrusion, invasion of "my" space.
- develop a portable "safe space" where sound enrichment strategies can be used to create a shield or barrier to intolerable sounds.
The careful use of ear protection can help maintain or allow expansion of lifestyle horizons. This may be in the form of customised solid silicon rubber plugs like those used to provide hearing protection at work and/or customised filtered musician's earplugs. The need for ear protection is evaluated and customised earplugs can be provided, with guidance given in appropriate use.
What can I expect from hyperacusis and misophonia therapy?
Desensitisation to intolerable sounds is a gradual process, where the situations previously uncomfortable will become gradually less so. If hyperacusis and tinnitus are present, the hyperacusis is usually addressed first. Frequently, as the hyperacusis becomes more under control, the tinnitus becomes less of an issue.
For many people, the information and guidance provided in one appointment may be sufficient to move towards a self-managed program of hyperacusis and misophonia desensitisation. For this reason, our initial appointment time is one and a half hours. However, the time involved in a program will vary, depending on the severity of your sound intolerance and the on-going guidance and support you may require.