Hyperacusis & Misophonia

What is hyperacusis?

Hyperacusis is defined as an abnormal sensitivity or intolerance, a heightened sense of volume, and physical discomfort towards certain sounds, which other people can comfortably tolerate. Sounds that are typically difficult to tolerate are loud/impact/sustained sounds, particularly if they are unexpected and in close proximity. High frequency (pitch) sounds tend to be tolerated less well.

Hyperacusis is the consequence of an involuntary sense of threat triggered by those sounds when they are subconsciously processed, often due to anxiety that they may cause damage, be painful or 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.

The consensus is that about 40% of people with troublesome tinnitus have some degree of hyperacusis. Recent large-scale prevalence research, including research carried out at our clinic, has identified the development of secondary hyperacusis in about 50% of help-seeking tinnitus patients.

What is misophonia?

Misophonia is defined as a strongly aversive response to certain specific sounds, irrespective of their volume and often made by other people. It may develop when those sounds become perceived as an intolerable intrusion into one’s sense of personal space.

People with misophonia struggle to tolerate specific sound triggers. These can include: the sounds of other people eating/breathing/swallowing, repetitive sounds (eg a pen tapping, keyboard tapping), neighbour’s music, dogs barking, noise from a nearby factory etc.

Misophonia involves an abnormal perception of loudness and a heightened awareness of these trigger sounds, and strong, emotional reactions following exposure to these sounds. Exposure to trigger sounds in people affected by misophonia can involuntarily result in high levels of irritation, intrusion, disgust or anger.

+How common is misophonia?

Online forums, support groups and media attention in the last few years have raised awareness of misophonia, suggesting it is more widespread and can potentially encompass a more severe level of reaction than was originally considered. Misophonia is not listed in the current DSM-5 or ICD-10 systems but is currently being investigated with regard to classification as a discrete psychiatric disorder, overlapping with many features of obsessive-compulsive disorder (OCD).

+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 isolation, anxiety and distress. Most people with hyperacusis will have physical symptoms in and around their ears consistent with TTTS, causing further anxiety and distress. TTTS symptoms can often be sound-induced or aggravated by sounds. With severe hyperacusis, sound-induced pain is a daily occurrence which is severe, highly debilitating and causes significant suffering.

There is little understanding of hyperacusis and/or misophonia in the community. Hyperacusis, misophonia, acoustic shock disorder, TTTS and the sound-induced pain associated with severe hyperacusis are involuntary and subjective. All these conditions and symptoms are readily misunderstood or not believed. Explaining such an abnormal reaction to sound to other people, including at times health professionals, is difficult and patients with hyperacusis and/or misophonia and/or acoustic shock 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 regards to their meaning or importance to us. Sounds that are considered important (either positively or negatively) will be transmitted to the more conscious parts of the 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.

Our brain at a subconscious level is strongly aimed at using our senses, particularly our hearing, to warn us of danger and keep us safe in our environment. In people with hyperacusis and misophonia, certain sounds become evaluated by their subconscious brain as unsafe and thereby judged as potentially threatening or damaging or intolerable or invasive etc. These judgements are below the level of rational thought and out of conscious control. For those with hyperacusis, if this judgement evaluates a sound as unsafe because it poses a risk to tinnitus/hearing/the ears, tonic tensor tympani syndrome (TTTS) symptoms can develop from a subconscious ‘need to protect’ the ear.

People with hyperacusis and/or misophonia can readily (and understandably) become highly focused or hypervigilant in listening for intolerable sounds in their environment. The subconscious brain will be highly alert to a sound deemed as unsafe. Reinforcing this by excessive monitoring at a conscious level entrenches hyperacusis/misophonia and promotes escalation. An important part of desensitisation is reducing environmental sound monitoring, to allow the subconscious brain to develop the opportunity to feel safer towards the vast range of unpredictable sounds we are typically exposed to on a daily basis. This is highly challenging, can seem counter-intuitive and needs to be approached gently without raising anxiety levels.

Our brain is a highly plastic organ, constantly reorganising and developing new neural connections. This means that we are able to retrain the brain to reverse the pathways which have 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 suffering, emotional impact and lifestyle constraints of hyperacusis/misophonia.

Tonic Tensor Tympani Syndrome (TTTS)

Westcott M et al. Tonic Tensor Tympani Syndrome in Tinnitus and Hyperacusis Patients: A Multi-Clinic Prevalence Study. Noise and Health Journal, Mar-Apr 2013, Volume 15, Issue 63 pp117-128

Acoustic shock and TTTS Guide for Medical Professionals

In the middle ear, the tensor tympani muscle and the stapedial muscle contract in response to loud, potentially damaging sounds. This tightens the ossicles (the tiny bones of the middle ear), limiting transmission of these sounds to the inner ear and providing protection.

In many people with tinnitus and almost all people with significant hyperacusis, an involuntary myoclonus (spasm) appears to develop in the tensor tympani muscle as an involuntary ‘protective’ response to sounds (or other stimuli) subconsciously evaluated as potentially painful, threatening or damaging to the ears/hearing or likely to stir up their tinnitus. This is known as tonic tensor tympani syndrome (TTTS).

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 and inflammation of the trigeminal nerve

As a result, TTTS can cause a range of symptoms in and around the ear(s). These include: a sensation of blockage, fullness or frequent “popping” in the ear; pain, numbness and burning sensations in and around the ear; the development of tinnitus or an increase in pre-existing tinnitus; pain in the jaw joint and down the neck; a clicking/fluttering sensation in the ear; mild vertigo/unsteadiness; muffled/distorted hearing.

For those affected, some/many/all of these symptoms may develop or be aggravated by exposure to intolerable sounds. For others, some/many/all of these symptoms may be more intermittent, occurring randomly.

It does not harm the ear to experience TTTS.

Even though TTTS symptoms can seem as if the ear is being significantly affected or even damaged by sounds, this is not the case. Moderate, everyday sounds are safe and do not harm the ear or cause a hearing loss.

How to deal with TTTS

As TTTS develops from an involuntary 'protective' response to sounds, understanding TTTS, effective pain management, managing stress and anxiety, and achieving tinnitus habituation/hyperacusis desensitisation will reduce TTTS symptoms.

Individual guidance from a skilled musculo-skeletal physiotherapist to provide neural desensitisation strategies including neural tapping, relaxation of the facial muscles in and around the ear, identification and massage of muscular trigger points in the shoulder and neck, will be of benefit.

Effective pain management is a priority for hyperacusis patients with severe sound-induced pain. Consulting a Pain Physician is recommended, where the treatment should be as for trigeminal neuralgia using nerve pain medication, such as Endep, Lyrica (Pregabalin, anticonvulsant). This approach, combined with neural tapping from a skilled physiotherapist and our hyperacusis therapy program, has been uniquely effective in these patients.

TTTS-like symptoms may be due to middle or inner ear pathology. TMJ dysfunction from jaw clenching and tooth grinding can result in TTTS. As a result, TTTS symptoms can be mistakenly diagnosed as due to middle/inner ear pathology or jaw joint (TMJ) dysfunction. Consulting an Ear, Nose and Throat Specialist/TMJ Specialist should be carried out to exclude these possibilities. When TTTS is solely a secondary consequence of TMJ dysfunction, the symptoms are not triggered/aggravated by sounds. With TTTS associated with tinnitus/hyperacusis, the primary cause is related to the way sound is perceived in the brain.

TTTS symptom desensitisation: refocussing strategies

The ‘protective’ mechanism of TTTS causes symptoms in the ears which are uncomfortable and cause anxiety. This can lead the brain to fear these symptoms, and consider the ears need to be ‘protected’ from further discomfort/anxiety by subconsciously triggering ongoing TTTS, which causes discomfort/anxiety …... Unfortunately, not at all an efficient mechanism.

Once TTTS has been diagnosed, there is no medical reason why the symptoms should be monitored. Overly anticipating and monitoring the symptoms will perpetuate this cycle and reinforce the brain’s need to ‘protect’ the ears. Additionally, over-monitoring will keep the symptoms prominent and reinforce awareness of them.

The best way to deal with TTTS symptoms is to train your brain not to monitor them – briefly acknowledge them when you notice them, then use refocussing strategies to reduce your symptom awareness.

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. Our program is part of a holistic multidisciplinary team, working with uniquely skilled and experienced physiotherapists, psychologists, a hypnotherapist and pain physicians.

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.

It has been our experience that once patients understand how the brain processes sound and understand in depth how their hyperacusis/misophonia developed, they have a possible pathway for reversal utilising the concepts of brain plasticity. This understanding provides reassurance, relief and insight, and is often helpful at relieving the suffering, distress, anxiety and bewilderment that tends to accompany both hyperacusis and misophonia, as well as the guilt, shame and anger that often accompanies misophonia.

+Therapy

For hyperacusis patients with frequent or severe sound-induced pain, the priority is effective pain management ahead of a hyperacusis desensitisation process. Consulting a Pain Physician is recommended, where the treatment should be as for trigeminal neuralgia using nerve pain medication, such as Endep, Lyrica (Pregabalin, anticonvulsant). This approach, combined with neural desensitisation from a skilled physiotherapist and our hyperacusis therapy program, has been uniquely effective in these patients.

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 recommended as part of the desensitisation process.

Hyperacusis/misophonia desensitisation therapy involves:

identifying how and why sounds changed from being tolerable to intolerable over time, so the process can be unravelled
an explanation of the peripheral and central auditory pathway, including the mechanisms of hyperacusis/misophonia and a personalised explanation of TTTS
a discussion about your thoughts and beliefs about your hyperacusis/misophonia – you may need to be open to accepting a new perspective
management of hypervigilance towards the auditory environment and any TTTS symptoms. Hypervigilance to intolerable sounds enhances and perpetuates the subconscious brain’s interpretation of these sounds as threatening. In the same way, excessive monitoring of TTTS symptoms perpetuates the subconscious brain’s “need to protect” the ears.
Sound enrichment strategies, creating a “safe space” where sound enrichment strategies can be used to create “auditory bubble” providing a cocoon to shield you from intolerable sounds
Advice on the use of ear plugs, including hearing aids set up as electronic filters. 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.

There are no guarantees that therapy will result in an improvement. The factors resulting in hyperacusis and misophonia are complex and outside a patient’s conscious control, so desensitisation is slow, requiring determination and belief in the prospect of change. 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 and misophonia.

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 require.

Hyperacusis & misophonia