What is tinnitus?

Tinnitus is commonly described as a ringing in the ears, but it also can sound like clicking, hissing, roaring or buzzing. It may be soft or loud, high pitched or low pitched. You might hear it in either one or both ears or in the head. Tinnitus is a symptom that indicates that something is not functioning normally in the auditory system. Auditory system includes the ear (outer ear, middle ear, inner ear) and the auditory nerve that connects the ear to the central auditory pathway of the brain. The end station of this auditory pathway is the auditory cortex where all the sounds are finally perceived and sensed.

How common is tinnitus?

Everyone feels sometimes ringing in the ears. If a person held in absolute silence, so 95% of us will hear the tinnitus sound. Population studies show that 10-15 % of the adult population have long lasting or persistent tinnitus. 1-3% of the tinnitus cause stress reaction, resulting in a difficulty in sleeping, anxiety and depression. Together with tinnitus often occurs in hyperacusia (in about half the cases), where even a little bit stronger sounds are perceived as disagreeable.

Where tinnitus comes from?  

There exists strictly regulated spontaneous bioelectrical activity in our brains and also in all parts of our auditory system. Normally, we are not aware of that because everyday activities and general background noise of our planet is masking it. When hearing becomes impaired - even only slightly (unmeasurable by audiometry) - the delicate balance is disturbed and inhibitory effects reduced. The background sound environment no longer masks spontaneus electrical activity. Then our brains interpret this activity as sounds (usually ringing or whistling). Tinnitus can also be triggered by many other factors, such as a stressful situation.

It is now generally accepted that tinnitus is associated with maladaptive neuronal 
 plasticity in the central auditory pathway. Chronic tinnitus is an example of maladaptive
 neuronal plasticity in a similar way as e.g. phantom pain in the amputated limb
 Tinnitus may secondarily trigger unwanted reactions from  limbic and autonomic systems, then tinnitus-sensation is accentuated and  patient`s symptoms are worsening.

What is the cause of tinnitus?

The exact cause of tinnitus often remains unknown. Today, exposure to loud music is the most common known cause of tinnitus. Adolescents and young adults often expose themselves to loud music and excessive noise levels during social and music events.  Such excessive noise levels are often obtained in night clubs where levels between 104 and 112dB(A) can be measured. Another source of leisure noise in the younger generation is personal listening devices (PLD’s) which many teenagers and young adults use at hazardous volume settings. Frequent leisure noise exposure louder than 90 dB(A) holds a significantly higher risk for the development of hearing problems.  

Neurophysiological basis of tinnitus 

It is now generally accepted that tinnitus is associated with maladaptive neuronal 
plasticity in the central auditory pathway. Chronic tinnitus is an example of maladaptive
neuronal plasticity in a similar way as e.g. phantom pain in the amputated limb. 

There exists strictly regulated spontaneous bioelectrical activity in our brains and also in all parts of our auditory system. Normally, we are not aware of that because everyday activities and general background noise of our planet is masking it. When hearing becomes impaired - even only slightly (can be unmeasurable by audiometry) - the delicate balance is disturbed and inhibitory effects reduced. The background sound environment no longer masks spontaneus electrical activity. Then our brains interpret this activity as sounds (usually ringing or whistling). 

Tinnitus and stress reaction

Tinnitus sound is strange and can be threatening because it can not be connected to earlier sound experiences. Therefore, it automatically produces an experience of threat and, correspondingly, an alarming or warning reaction. Autonomic nervous system reacts to a threat situation by activating the sympathetic system. The heart rate accelerates, blood pressure and blood supply to muscles increase and, particularly, attention is directed to the new strange sound. If the new sound is interpreted as pleasant, it is triggering a parasympathetic (relax) response. 

Tinnitus may secondarily trigger unwanted reactions from  limbic and autonomic systems, then tinnitus-sensation is accentuated and patiens symptoms are worsening. Tinnitus is, at its strongest form, so distressing experience that everyones first questions are:
Where can this come from?
Is this my endless destiny?
What is my future?
The crucial component of handling tinnitus is the understanding of the mechanisms of the formation of tinnitus. The understanding namely increases the experience of control and thus getting hold of the situation instead of fateful subservience. Connecting fear to tinnitus activates our limbic system that decides is the new experience pleasant or threatining. Our limbic system thus prepares to possible threat if new sound appears strange or otherwise abnormal Furthermore, our limbic system activates our autonomic nervous system (ANS) to act appropriately: to prepare for facing the threat = sympathetic activation- ”fight or fly”.