Brief overview
- Diagnostics: Hearing tests, test of the discomfort threshold, medical history, examination of the ear, test of the stapedius reflex in the ear.
- Causes: Often unknown, faulty processing of what is heard in the brain; neurological damage or pathological changes in the inner ear due to illness or injury; psychological stress; tinnitus concomitant symptom
- When to see a doctor: In case of sudden onset, especially in conjunction with other symptoms such as facial paralysis, immediately (stroke possible, notify emergency services).
- Treatment: If the cause is unknown, usually symptomatic, including psychotherapeutic measures; hearing training, listening exercises, creation of “background noise
- Prevention: No specific prevention possible; avoid noise in general; wear appropriate hearing protection at work, concerts and the like.
What is hyperacusis?
People with hyperacusis find even moderately loud or even soft sounds unpleasant (in one or both ears). Although the volume of such sounds is actually far below the threshold of pain, it is perceived as unpleasant by the affected person and in many cases even triggers physical stress reactions.
The degree of noise hypersensitivity varies from case to case. Everyday noises are not only subjectively perceived as unpleasant by those affected, they also lead to physical reactions such as a racing heart, increased blood pressure, sweating, tension in the shoulder and neck area, anxiety or restlessness. Many sufferers withdraw socially and avoid activities in public to minimize exposure to unpleasant sounds.
Other forms of noise sensitivity
To be distinguished from hyperacusis are misophonia (= hypersensitivity to specific sounds, such as scratching chalk on the blackboard) and phonophobia (= fear of or aversion to specific sounds).
Recruitment should also be distinguished. This is the sensitivity of some people with sensorineural hearing loss to sounds in the frequency range that is (most) affected by the hearing loss: above a certain volume level in the impaired frequency range, the sound is perceived as excessively loud because the body recruits neighboring auditory cells to compensate for the hearing loss. Recruitment is a side effect of sensorineural hearing loss and has nothing to do with general hyperacusis.
How do you test for hyperacusis?
It is also important to ask about other diseases, other neurological symptoms, or what medications the patient is taking.
In the hearing test, hyperacusis often shows normal to very good hearing (exception: recruitment, see above). Anomalies are found when testing the so-called discomfort threshold: this is the volume above which sounds are perceived as unpleasant. This threshold is lowered in people who are sensitive to noise.
Depending on the additional symptoms, the doctor will perform further examinations for more detailed clarification. This may include an examination of the so-called stapedius reflex in the inner ear, which normally protects against damage caused by excessive loudness.
What causes hyperacusis?
Hyperacusis has many possible causes or occurs as a symptom of other conditions. Possible causes include:
A disturbance in auditory processing in the brain: in those affected, the processing and interpretation of auditory signals in the brain is then disturbed. Normally, the human brain distinguishes important from unimportant sounds and blocks out the latter. For example, a mother is awake at the slightest sound her baby makes, while street noise lets her sleep peacefully.
Secondary or co-symptom in tinnitus: Often the increased sensitivity to sound occurs in people with ringing in the ears (tinnitus). However, this does not mean that the tinnitus is the cause of the hyperacusis. Nor is hyperacusis the cause of the tinnitus. Instead, both symptoms – ringing in the ears and hyperacusis – are likely due to the same damage in the auditory system and occur both together and separately.
After a hearing loss, some sufferers report that everyday sounds that would normally be tolerable in terms of volume are now far too loud for them.
Many patients with functional pain syndromes (such as fibromyalgia, complex regional pain syndrome) also suffer from hyperacusis. In these cases, common neurological problems likely underlie the symptoms.
Sometimes, hyperacusis of sound occurs with unilateral or bilateral facial paralysis (facial nerve palsy). This has many possible causes, for example stroke, multiple sclerosis, autoimmune diseases, infections (such as otitis media, “shingles in the ear” = zoster oticus) or injuries. In many cases, however, the cause of the facial paralysis also remains unknown (Bell’s palsy).
As a result, the vibration is not completely transmitted from the eardrum to the cochlea, thus sparing the sensitive sensory cells. If this reflex fails, hyperacusis is a possible consequence.
Neurological disorders that lead to hyperacusis also occur in diseases such as Sandhoff’s disease or Tay-Sachs syndrome.
Pathological stiffening of the ossicles (otosclerosis) is another possible cause, as well as surgery for this condition with prostheses of the ossicles.
Inner ear disorders in which the outer hair cells (= the sound-receiving sensory cells in the cochlea) are hyperactive.
Emotional stress – acute and chronic – favors the occurrence of sound hypersensitivity. In some cases, hyperacusis is a physical symptom of psychological distress such as stress. It also occurs as an accompanying symptom of an anxiety disorder.
Transient hyperacusis is familiar to many migraine patients: During attacks, sufferers perceive even “normal” sounds as too loud and unpleasant.
Sometimes hyperacusis is caused by drugs or other exogenous substances such as acetylsalicylic acid, caffeine, quinine or carbon dioxide. Hyperacusis of sound also occurs in some cases during withdrawal from benzodiazepines (“tranquilizers”).
When to see a doctor?
Especially if you suddenly experience additional symptoms, such as facial paralysis, which may indicate a stroke, notify the emergency services immediately. Urgency is then required.
The sensitivity to sound may be a symptom of a deeper disease. However, the doctor can also help to alleviate the hyperacusis if the cause cannot be found specifically.
Treatment
Hyperacusis cannot be solved with earplugs. The focus is on informing and counseling the patient in detail about the physical and psychological causes and correlations of the hyperacusis and how to deal with it (counseling). If the cause of the hyperacusis is a disease of the inner ear, for example, the physician treats it accordingly.
In the context of psychosomatic (psychotherapeutic) treatment, special attention is paid to existing fears: many sufferers are very afraid that their sensitivity to noise will continue to increase and that their hearing will be permanently damaged. It is important to allay these fears.
For many sufferers, it is also helpful to provide a constant background of quiet noise at home – for example, with an indoor fountain, soft music, a CD with nature sounds (such as birds chirping) or a fan. Ideally, the volume should be just perceptible and not disturbing. In this way, the brain learns to tune out unimportant sounds. However, this process of habituation usually takes a long time (about several months).
Other treatment options include technical aids such as a noiser (a small device similar to hearing aids that produces individually adjustable sounds) and hearing-specific exercises. These also help sufferers to reduce their hypersensitivity to sound (hyperacusis).
In addition to symptomatic treatment, the doctor will treat other conditions found to be causative. In many cases, however, the cause of hyperacusis remains unclear.
Prevention
Concrete prevention of hyperacusis is not possible. In general, it is advisable to avoid excessive exposure to noise or to use hearing protection at work and during leisure time (concerts, clubbing, etc.).
