The denominator "sound hypersensitivity"

Many people think that overstimulation for sound and hyperacusis are the same. That is not true. A mixed picture of hyperacusis and overstimulation by sound may arise after brain injury. They may also occur separately. The two concepts are summarized under the unclear denominator "sound hypersensitivity".


Short explanation

With hyperacusis the dynamic range of hearing has decreased, ears cannot adjust to changes in loudness. Sounds are perceived as too loud, sharp or painful. The sound tolerance limit has dropped. Hyperacusis can be measured by a UCL test, uncomfortable loudness test. Above a limit, sound becomes intolerable.


Over-stimulation for sound means that people cannot separate sounds properly, background noise immediately imposes itself as foreground sound, but people are not necessarily bothered by volume. In the UCL test (uncomfortable loudness test), people with only sound stimulation do not appear to have a different score. The sound tolerance limit has not dropped.


Difference with overstimulation by sound

In case of over-stimulation for sound, a person cannot stand multiple sound sources. The brain cannot filter the sounds. This person cannot tolerate background noise or may experience all sound as a mixture of sounds. Following a conversation in noise becomes impossible. It is impossible to understand what is being said when someone else is talking in the room at the same time.


When this person is tired or very busy, sound is no longer tolerated. A stacking effect occurs between other forms of sensory and cognitive stimulation. This is a common invalidating and socially isolating consequence of brain injury. Rest and stopping background noise are the only remedies.


With hyperacusis, the sound hurts or sounds as intolerably loud, or sharply experienced, and the ear cannot adjust quickly to varying volume. Living with an inner volume control that is constantly on too loud.


Dynamic range lost and pain

With hyperacusis the ears have lost their so-called "dynamic range". This is the ability of our ears to quickly adapt to changing sound levels. The sound tolerance limit has dropped. Normally someone can still tolerate 80-90 dB well.


Sound can hurt and can be experienced as unbearable and too loud or sharp. It seems as if the volume control is constantly too loud. The hearing care professional can do a UCL test, an Uncomfortable Loudness test (UnComfortable Level).


A person with hyperacusis does not have to have a hearing loss. If someone with hyperacusis does have hearing loss, it is called 'recruitment'. Recruitment involves a damaged inner ear.


Characteristics hyperacusis

  • Feeling uncomfortable with sound,
  • People who suffer from this cover their ears or try to get away from the noise,
  • People who suffer from this can be angry, tense, sad or anxious about noise
  • People experience sound as painful, sharp or unbearably loud
  • Sound tolerance limit has dropped
  • Dynamic range of hearing has decreased, ears cannot adjust to changes in volume.



  • Research is still being done into causes, but not everything is known

  • Exposure, in the present and the past, to loud noise, for example in the workplace, but also to exposure to loud music

  • Head and brain injuries, including whiplash

  • Brain tumor

  • Use of certain medicines

  • Squirting the ear which was done careless

  • Problems with the jaw joint (eg Cranio Mandibular Joint (CMD)

  • CPRS - Complex Regional Pain Syndrome

  • Heredity,

  • Lyme disease (tick bite)


Furthermore, it can be a symptom of:

  • Migraine
  • Ménière's disease (attacks of vertigo, poor hearing and ringing in the ears)
  • Bell's Palsy (acute paralysis of the facial nerve)
  • William's Syndrome / Williams Beuren syndrome (delayed development, heart defect and behavioral problems)
  • Tay-Sachs disease (metabolic disease)
  • Fibromyalgia (non-joint-related chronic muscle connective tissue pain and pressure point pain / soft tissue rheumatism)
  • Autism (According to American research, 40% of people with autism spectrum disorder are hypersensitive to loud sounds)
  • Some cry babies seem to be sensitive to sounds, whether or not in combination with other factors


A third problem: tinnitus

Hyperacusis, literally translated from Greek for 'hearing too much', often occurs in combination with ringing in the ears.

Tinnitus, or ringing in the ears, is derived from the Latin word for 'ringing'. It is hearing damage and includes various sounds that cannot be heard outside the head: whistling sounds, buzzing, hissing, ringing or grumbling up to and including waterfall sounds. If the cilia in the ear are damaged, you will hear worse or they will pass on the wrong information, such as a beep, hum or a noise.

There are various causes for tinnitus.

  • High blood pressure
  • Infectious diseases
  • Side effect of medicines
  • Exposure to noise


Please note that terms are confused when it comes to sound problems with brain injury. We hope to have highlighted on this page the differences between: