Lec 18: Sound Intolerance 1: Hyperacusis & Misophonia

Introduction and Speaker Background

• Miriam Westcott is a world-renowned expert in sound intolerance and tinnitus with decades of clinical experience.

• She founded the clinic originally known as Deneen Westcott in Heidelberg, which has since evolved into Deneen Westcott Moore (DWM).

• Westcott is a graduate of the very first cohort of the audiology course at the University of Melbourne.

• She retired from clinical practice last year ($2023$) but continues to provide mentorship and online training globally.

• Her interest in the field was sparked by her first patient, who developed severe tinnitus and hyperacusis following a car accident.

• She is a proponent of a multidisciplinary approach and has contributed several publications to the field from a clinical perspective.

Definitions and Core Concepts of Sound Intolerance

• Definitions in the field of sound intolerance are often confusing and overlapping, but can generally be categorized into two streams: Hyperacusis and Misophonia.

• Hyperacusis:

  • Defined as an abnormal sensitivity or intolerance of everyday sounds.

  • It impacts a person's functioning and quality of life.

  • It involves a "central gain" theory: the brain's subconscious processing identifies certain sounds as important/threatening and increases their volume/prominence before they reach conscious awareness.

  • Characterized by physical discomfort in or around the ear (e.g., pain, blockage, pressure).

  • Triggered typically by loud, moderate-volume, impulse (banging), or unexpected sounds (e.g., dropping a plate, putting a cup on a desk).

• Misophonia:

  • Defined as an aversive response to specific sounds, regardless of their volume.

  • Usually involves sounds made by other humans, such as mouth noises (eating, chewing, swallowing) and nasal sounds (sniffing, breathing).

  • Includes repetitive sounds like keyboard tapping or a neighbor's air conditioner.

  • Characterized by a disproportionate emotional response of anger, rage, irritation, or disgust.

  • Concepts of "auditory privacy" and "personal space" are central to misophonia, particularly regarding intrusive sounds (neighbor's music, a barking dog).

• Evolutionary Context of Hearing:

  • Hearing is a survival sense hardwired in the brain to warn of danger/predators.

  • Unlike the eyes, ears cannot be closed; the brain must constantly suppress the majority of heard sounds to prevent bombardment.

  • Even with normal hearing, humans can theoretically hear atoms moving; the brain's dynamic range and suppression capabilities are vast.

Predisposing Factors and Triggers

• Tinnitus:

  • Research by Westcott and large databases in Germany indicate that approximately $50\%$ of people sufficiently bothered by tinnitus have the potential to develop hyperacusis.

  • Tinnitus is often under-diagnosed in hyperacusis patients and vice versa.

• Acoustic Shock:

  • An involuntary fright or psychological trauma response to an unexpected, loud sound near the ear.

  • Originally identified in call center environments where employees wear headsets.

  • Can cause sharp, stabbing ear pain and lead to a lasting threat response to similar sounds.

• Psychological Factors:

  • High levels of health-related anxiety can lead to "subconscious protectiveness."

  • Patients often worry that loud sounds will damage their ears further or aggravate their tinnitus.

• Abrupt Changes in Hearing:

  • Sudden onset hearing loss or Meniere’s disease causes sudden recruitment.

  • Unlike gradual loss where the brain adapts, sudden loss makes sounds jarring and harsh, leading to a threat response.

  • Poor management of newly fitted hearing aids (over-amplification without preparation for the cognitive load of hearing again) can also trigger hyperacusis.

• Medical and Neurological Conditions:

  • Superior Semicircular Canal Dehiscence (SSCD): Heightened perception of internal bodily sounds (autophony).

  • Post-concussion syndrome and head injuries.

  • Neurodivergence (Autism, ADHD).

  • Conditions involving chronic pain/fatigue: Chronic Fatigue Syndrome, Fibromyalgia, and Lyme Disease.

Psychological Mechanisms: Placebo and Nocebo Effects

• The Placebo Effect:

  • An involuntary reaction where symptoms improve due to a positive mindset or belief in a treatment.

  • Not just "positive thinking," but a subconscious response.

  • Tinnitus is highly responsive to placebo; study data from $1984$ shows $40\%$ of patients reported over $25\%$ improvement following a placebo treatment.

• The Nocebo Effect:

  • If a patient believes a stimulus will harm them, the brain becomes protective, often inducing pain or worsening symptoms.

  • In the context of "Tinnitus Disorder," there is a subconscious drive to avoid sounds, medications, or foods perceived as triggers.

  • Example: Stress during COVID-$19$ led patients to monitor their tinnitus more closely after vaccinations, often misattributing a stress-induced spike to the vaccine itself.

  • Westcott notes that the brain can "turn on pain in the face of a perceived threat."

Neurophysiological Pathways

• Auditory Pathway Steps:

  • Tinnitus emerges at the very first step of the brain's processing: the cochlear nucleus in the brainstem.

  • Sounds reach conscious awareness only when they arrive at the cortex.

  • There is a massive amount of processing, evaluation, and filtering occurring below the level of conscious awareness.

• Limbic and Somatosensory Interaction:

  • Auditory structures are strongly connected to the limbic system (emotional and threat response center).

  • Tinnitus can also be triggered or modulated by somatosensory input, particularly from the jaw (Temporomandibular Joint - TMJ) and neck muscles.

  • Stress held in the jaw (clenching/grinding) is processed in the same brain region where tinnitus emerges.

  • Tensor Tympani Syndrome (TTS): Spasming of the middle ear muscle (tensor tympani) as a protective mechanism, causing pain or ear clicking.

Developmental and Social Aspects of Misophonia

• Onset and Childhood:

  • Typically stems from a specific childhood instance (average age of onset is $12$ in neurotypical children) involving a loved one (e.g., a sibling or parent eating gross sounds in a car).

  • It is often selective: a teenager might be triggered by their mother's eating but not their best friend's mother's eating.

• Impact on the Home:

  • For neurotypical people, the home is the most triggering space because it is supposed to be a sanctuary.

  • It causes immense guilt and shame because the rage is directed at loved ones.

• Neurodivergence Differences:

  • Neurodivergent individuals (ADHD/Autism) are more likely to be triggered outside the home due to sensory overload and lack of control over the environment.

  • ADHD involves intense distraction; a fan or TV voices can prevent focus on a teacher's voice.

Clinical Assessment and Diagnosis

• History Taking:

  • Consultation usually lasts $90$ minutes, with $60$ minutes dedicated solely to history and explanation.

  • Explores otological history, psychological history, specific intolerable sounds, and the context of the onset (stress levels, physical factors).

• Questionnaires:

  • Inventory of Hyperacusis Symptoms (IHS): Measures severity based on meaningful activity impact.

  • A MISO S: A misophonia questionnaire from a clinic in Amsterdam (originally an OCD clinic).

  • DASS-$21$: Used to screen for levels of depression, anxiety, and stress.

• Testing Precautions:

  • Avoid super-threshold testing and acoustic reflex testing, as these can trigger a severe threat response.

  • Use an ascending technique for audiometry.

  • Loudness Discomfort Testing (LDL) is strongly discouraged: Westcott argues it is unethical to drive a patient into a threat response for the sake of a measurement.

Management and Therapy Strategies

• Therapeutic Approach:

  • Paternalistic medicine ("I will fix you") is avoided in favor of self-management.

  • The goal is to demystify symptoms and explain the neurophysiological pathways to provide reassurance.

  • Use of Third Tier CBT, including Acceptance and Commitment Therapy (ACT), to help patients coexist with their symptoms.

• Auditory Hypervigilance Management:

  • Distinguishes between reasonable alertness and constant monitoring.

  • Patients should rank environments into "safe," "unsafe," and "moderately unsafe."

  • In "unsafe" environments, ear protection (e.g., earplugs) is encouraged to maintain lifestyle horizons and prevent social isolation.

• Sound Enrichment:

  • Use of low-level, stable, predictable sounds (e.g., sound of the sea without bird squawks).

  • For severe hyperacusis, sound should be kept away from the ear canal (e.g., neck speakers or shoulder-mounted devices) to avoid triggering TTS through touch or proximity.

• Multidisciplinary Team:

  • Includes physiotherapists/myotherapists (for jaw and neck work), jaw specialists, pain physicians, psychologists (specifically those who are trauma-informed), and hypnotherapists.

Technical Interventions: Electronic Filters and Bimodal Stimulation

• Hearing Aids as Electronic Filters:

  • High-end hearing aids can be programmed with very high compression (turning down the G$80$) and very low Maximum Power Output (MPO).

  • This acts as an "electronic filter" to make loud environments tolerable while allowing communication.

  • Not suitable for all; some find the sound being "right in the ear" to be a threat.

• Bimodal Stimulation (The Lanier Device):

  • An FDA-approved device (launching in Australia in late $2024$) that provides simultaneous acoustic stimulus (ear) and electrical/vibratory stimulus (tongue).

  • Theoretical basis: influencing the cochlear nucleus via multiple sensory inputs.

Case Studies

• Case Study: Colin ($22$):

  • Diagnosis: ADHD, OCD, severe Misophonia, and Misokinesia (aversion to repetitive movements, specifically feet).

  • Onset: Age $8$ with triggers related to his sister’s eating.

  • Response: Intense "fight or flight" heat and rage.

  • Management: Pathways explanation, hypervigilance management, and referral to a specialized psychologist. Success achieved through stopping further escalation.

• Case Study: Violet:

  • Diagnosis: Sudden onset hearing loss in the right ear ($20$ sessions of hyperbaric oxygen therapy) and hyperacusis in the left (the "functional") ear.

  • Management: Fitted with a custom hearing aid in the left ear as an electronic filter. It allowed her to return to her business and even stream phone calls through the filter. She also tried the Lanier device in Germany; while she couldn't hear the acoustic stimulus due to her loss, she found it helped her psychologically to cope.

Questions & Discussion

• Student Question: "How long on average would a detailed history take?"

• Miriam Westcott Response: It usually takes an hour within a $90$-minute consultation. The explanation and history are the most important parts for patient self-management.

• Audience Interaction regarding Wax Removal: A student (Madeline) mentioned seeing patients anxious about wax removal. Westcott agreed, noting that micro-suction is invasive, loud, and triggers the brain's "protective mode" since it occurs right next to the eardrum.

Hyperacusis and Misophonia – Detailed Lecture Notes

Learning Focus

The lecture focused on:

• Hyperacusis

• Misophonia

• Acoustic shock (briefly)

• Tensor Tympani Syndrome (TTS) (briefly)

• Assessment and management approaches

• Clinical reasoning and case studies

Introduction to Sound Intolerance

General Issues

Sound intolerance remains:

• Poorly understood worldwide

• Associated with confusing definitions

• Characterised by inconsistent classification systems

• Difficult for both clinicians and patients to navigate

Miriam proposed two major categories:

1. Hyperacusis

2. Misophonia

These are different disorders, although a person may experience both.

Hyperacusis

Definition

Hyperacusis = An abnormal sensitivity/intolerance of certain everyday sounds

+ a heightened sense of volume (central gain) to those sounds

+ physical discomfort from those sounds

The issue is not simply disliking sounds.

The condition becomes clinically significant when it:

• Affects daily functioning

• Causes distress

• Interferes with participation in life activities

Evolutionary Perspective

Hearing is fundamentally a survival sense.

Important points:

• The auditory system evolved primarily for danger detection.

• Hearing became useful for communication later in evolution.

• The ears are always open.

• Humans cannot "close" their ears like they can close their eyes.

• The brain is continuously bombarded by sound information.

The brain therefore suppresses large amounts of auditory information.

Central Gain Concept

A proposed mechanism:

• Sounds considered important are given increased prominence.

• The brain effectively increases their perceived loudness.

• This process is referred to as central gain.

Symptoms

Most people with hyperacusis experience:

Physical symptoms

• Pain

• Pressure

• Blockage sensations

• Ear discomfort

Emotional symptoms

• Anxiety

• Panic

• Distress

• Fear

Sounds Commonly Associated with Hyperacusis

Loud sounds

Examples:

• Machinery

• Traffic

• Loud environments

Moderate sounds

Examples:

• Everyday household sounds

Impact/Impulse sounds

Examples:

• Plates dropping

• Sudden bangs

• Objects striking surfaces

Particularly problematic when sounds are:

• Unexpected

• Close to the ears

• Unavoidable

Misophonia

Definition

Misophonia = "I hate that sound."

It is:

• A strongly aversive response to certain specific sounds, often made by

  other people, irrespective of their volume.

Core Characteristics

Misophonia is characterised by:

• Irritation

• Disgust

• Anger

• Rage

• Feelings of intrusion

The emotional response is disproportionate to the actual sound.

This is not a judgemental description but a clinical observation.

Common Trigger Sounds

Human-generated sounds

• Eating

• Chewing

• Sniffing

• Breathing

Repetitive sounds

• Keyboard tapping

• Repetitive movement sounds

• Rhythmic environmental sounds

Intrusive sounds

Examples:

• Neighbour's music

• Air conditioners

• Factory sounds

• Barking dogs

These sounds are often perceived as invading personal space.

Predisposing Factors for Hyperacusis

1. Tinnitus

One of the most common risk factors.

Research findings:

• Approximately 50% of people seeking help for tinnitus may have hyperacusis potential.

• Hyperacusis is often underdiagnosed in tinnitus populations.

Clinical implication:

Every tinnitus patient should be asked:

"How do you cope with everyday sounds?"

2. Acoustic Shock

Definition

An involuntary fright reaction or trauma response to:

• Sudden

• Loud

• Unexpected sounds near the ear

Initially recognised in:

• Call centre workers wearing headsets

Symptoms

May include:

• Sharp stabbing ear pain

• Ongoing sound sensitivity

• Threat responses to similar sounds

3. Misophonia Progression

Misophonia may:

• Escalate into threat-based responses

• Increase vulnerability to hyperacusis

People may develop:

• Misophonia alone

• Hyperacusis alone

• Both conditions together

4. Health-Related Anxiety

Important clarification:

Anxiety does not necessarily cause hyperacusis.

However:

• Anxiety increases monitoring behaviours.

• Individuals become highly aware of sounds.

• People worry about tinnitus worsening.

• People worry about hearing damage.

This increases vulnerability to hyperacusis.

Concept of Safety

The lecturer emphasised:

Hyperacusis is not only about acoustic safety.

It is about whether the person feels safe in their acoustic environment.

This distinction is crucial.

5. Abrupt Hearing Changes

Examples:

• Sudden sensorineural hearing loss

• Ménière's disease

• Other sudden auditory changes

Because recruitment appears suddenly:

• Sounds become harsh

• Sounds become jarring

• Sounds become threatening

6. Newly Fitted Hearing Aids

If amplification is introduced poorly:

• Sounds may seem threatening

• Recruitment may be overwhelming

• Hyperacusis can develop

Clinical implication:

• Prepare patients carefully

• Use graded amplification approaches

Wax Removal and Sound Intolerance

Wax removal may trigger hyperacusis because:

• It is invasive

• It occurs close to the ear

• It can activate protective brain responses

The lecturer has seen multiple referrals after wax removal procedures.

Clinical recommendation:

• Acknowledge patient discomfort

• Monitor patient reactions

• Avoid assuming the procedure feels routine to patients

Superior Semicircular Canal Dehiscence

Can produce heightened awareness of internal body sounds.

Possible consequences:

• Aversion to internal sounds

• Misophonia-type reactions

• Hyperacusis-type reactions

Neurological Factors

Associated conditions include:

• Head injury

• Post-concussion syndrome

• Neurological disorders

• Central auditory pathway dysfunction

Neurodivergence

Higher risk in:

• Autism

• ADHD

These individuals are more likely to develop:

• Misophonia

• Hyperacusis

Chronic Illness and Protective Brain States

Associated conditions:

• Chronic fatigue syndrome

• Fibromyalgia

• Lyme disease

The brain may already be operating in a protective mode, increasing vulnerability to sound intolerance.

Placebo Effect

Definition

a real phenomenon where a person's symptoms improve after receiving a fake (placebo) treatment.

Important observations:

• Tinnitus is highly responsive to placebo effects.

• Many treatments appear effective partly due to placebo mechanisms.

Research cited:

• Around 40% of patients may experience >25% tinnitus improvement from placebo interventions.

Nocebo Effect

Definition

a mindset of anxiety and vigilance triggering heightened levels of stress about these stimuli can lead to a subconsciously driven increase in tinnitus (nocebo effect)

→ If a person believes something will cause harm, symptoms may worsen.

Examples:

• Medications

• Vaccinations

• Foods

• Environmental sounds

The brain enters a protective state.

COVID Vaccine Example

Many tinnitus sufferers worried the vaccine would worsen tinnitus.

The lecturer noted:

• Anxiety leads to monitoring.

• Monitoring increases tinnitus awareness.

• Increased tinnitus is then attributed to the vaccine.

This illustrates a nocebo response.

Hyperacusis Development Model

Hyperacusis is viewed as:

• Involuntary

• Subconscious

• Threat-based

• Nocebo effect: primeval fear that intolerable sounds are unsafe and will aggravate tinnitus; cause harm to the ear/hearing; cause pain

People often feel confused rather than anxious initially.

Anxiety develops later because sounds are unavoidable.

Fear Components

People fear:

• Hearing damage

• Tinnitus worsening

• Ear injury

• Sound-induced pain

Tensor Tympani Syndrome (TTS)

Key Concept

TTS is:

• A protective muscle response

• Not evidence of damage

Symptoms may include:

• Pain

• Ear discomfort

• Pressure sensations

The brain begins fearing:

• Sounds

• Sound-induced symptoms

This creates escalation cycles.

Trauma Associations

Traumatic experiences can become linked with sounds.

Examples:

• Acoustic shock

• Car accidents

Specific sounds may later trigger strong threat responses.

Hyperacusis = result of a subconscious, primeval threat strongly influencing auditory processing, triggered by specific, everyday sounds.

Development of Misophonia

Often begins in childhood.

Typical scenario:

• A strongly negative experience involving sound

• Usually involving a loved one

Example:

• Family member eating loudly during a long car trip

Average Age of Onset

Neurotypical individuals:

• Approximately 12 years old

Coincides with:

• Desire for privacy

• Increased sensitivity to family behaviours

Family Impact

Misophonia commonly affects:

• Parent-child relationships

• Family dynamics

• Romantic relationships

The strongest triggers are often the people the individual loves most.

Consequences:

• Shame

• Guilt

• Relationship strain

Neurophysiological Concepts

The lecturer uses simplified diagrams to explain:

• Auditory pathways

• Tinnitus generation

• Emotional processing systems

• Threat processing systems

Limbic System

The auditory system is strongly connected to:

• Emotional processing

• Threat processing

These systems influence:

• Sound importance

• Tinnitus awareness

• Hyperacusis reactions

Conscious Awareness

Not all sounds reach conscious awareness.

The brain filters incoming information.

Only sounds judged important reach conscious perception.

Somatosensory Influence on Tinnitus

Jaw and muscle tension contribute significantly.

Examples:

• Clenching

• Teeth grinding

• TMJ tension

These can:

• Influence tinnitus

• Potentially trigger tinnitus

Neurodivergence and Sound Intolerance

Key issues:

• Sensory filtering difficulties

• More sounds entering awareness

• Increased overwhelm

• Stronger emotional responses

ADHD

Problems include:

• Auditory distraction

• Difficulty maintaining focus

• Competing sounds becoming intolerable

Autism

Can involve:

• Increased sound sensitivity

• Hyperacusis

• Misophonia

Trauma-Related Misophonia Example

A patient developed breathing-sound triggers because:

• Breathing sounds were present during childhood sexual abuse.

This illustrates how trauma can create powerful sound associations.

Clinical Assessment

Questionnaires

Hyperacusis

Inventory of Hyperacusis Symptoms (IHS)

Used to estimate severity.

Misophonia

Amsterdam Misophonia Scale (A MISO S)

Audiological Assessment Considerations

For hyperacusis patients:

Recommended

• Ascending audiometry techniques

• Careful testing

Avoid

• Loudness discomfort testing

• Suprathreshold testing

• Unnecessary acoustic reflex testing

Reason:

These procedures can worsen symptoms.

History Taking

The lecturer considers history taking the most important component.

Areas explored:

• Otological history

• Psychological history

• Sound triggers

• Physical responses

• Emotional responses

• Onset circumstances

• Stress levels

• Jaw symptoms

• Contributing factors

Clinical Philosophy

The lecturer emphasises:

• Compassion

• Personalisation

• Collaboration

• Detailed explanation

Patients need:

• Validation

• Understanding

• Diagnosis

• Education

Therapeutic Goals

• Reduce distress

• Prevent escalation

• Increase understanding

• Promote self-management

• Encourage recovery

Auditory Hypervigilance

Important distinction:

Reasonable Alertness

Adaptive.

Hypervigilance

Maintains threat responses.

Monitoring:

• Trigger sounds

• Tinnitus

prevents desensitisation.

Safe vs Unsafe Environments

Patients rank environments as:

Safe

• No protection needed

Moderately Unsafe

• Limited protection

• Therapeutic sound use

Unsafe

• Ear protection acceptable

Goal:

Maintain participation in life.

Sound Enrichment

Can be highly effective.

Characteristics:

• Low level

• Predictable

• Stable

• Non-threatening

Examples:

• Ocean sounds

• Gentle environmental sounds

Avoid:

• Unpredictable sounds

• Sounds delivered too close to the ears in severe hyperacusis

Hearing Aids and Hyperacusis

Severe hyperacusis patients may struggle with:

• Amplification

• Physical device contact

• Occlusion effects

• Own voice amplification

Recommendation:

Treat hyperacusis first.

Fit hearing aids later.

Multidisciplinary Team

Potential referrals:

• Physiotherapists

• Myotherapists

• Pain specialists

• ENTs

• Psychologists

• Hypnotherapists

• Occupational therapists

• Jaw specialists

Case Study: Colin

Background

• Male

• 22 years old

• ADHD

• OCD

History

Onset:

• Around age 8

Initial trigger:

• Sister's eating sounds

Progression:

• Eating sounds → breathing sounds → many other sounds

Developed:

• Hypervigilance

• Anticipatory anxiety

• Avoidance behaviours

Additional Feature

Misokinesia:

Strong aversion to repetitive movements, particularly feet movements.

Emotional Response

Trigger sounds caused:

• Anger

• Annoyance

• Disgust

• Distress

Assessment

• Normal hearing

• Severe misophonia on questionnaire

Management

• Education

• Pathway explanation

• Hypervigilance management

• Sound enrichment

• Anger management strategies

• Referral to psychologist specialising in misophonia

Outcome:

• Escalation stopped

• Reactivity reduced

• Improved coping

Sound Enrichment Success Example

A young woman with misophonia:

• Used low-level sound generators

• Wore them consistently for two years

Outcome:

• Misophonia resolved

• No further treatment required

The lecturer viewed this as evidence of the potential effectiveness of sound enrichment.

Case Study: Violet

History

• Sudden sensorineural hearing loss

• Tinnitus

• Hyperacusis symptoms

Management

Included:

• Hearing aids

• Electronic filtering approaches

• Gradual amplification

Outcome:

• Returned to running her business

• Reduced sound-induced discomfort

• Improved quality of life