What is sudden hearing loss?

No. Sudden hearing loss is classified as an illness, whereas tinnitus is considered a symptom. Sudden hearing loss and tinnitus can occur together. With chronic tinnitus, sudden hearing loss may disappear while the tinnitus symptoms remain.

While our knowledge is limited, one possible cause has to do with circulatory disorders in the smallest vessels of the inner ear (microcirculation). Other contributing factors include:

• Stress
• Viral infections or reactivations (for example, herpes or chickenpox)
• Arteriosclerosis and subsequent circulatory disorders
• Metabolic disorders such as diabetes or high cholesterol levels
• A ruptured oval or round window (inner ear)
• Cervical spine injury (for example, whiplash)
• Elevated platelet aggregation (blood clots)
• Occlusion (thrombosis) of the inner ear’s vessels
• Autoimmune diseases
• Previous acute otitis media (middle ear infection)

We can assume there are additional causes, which are frequently discussed by specialists and experts.

Idiopathic means “without recognisable cause”. This is the most common type of sudden hearing loss. An extensive examination cannot determine an organic cause.

Stress is a frequent trigger for sudden hearing loss. It’s assumed that the stress hormone adrenaline causes the small vessels to narrow. The exact manner of development is unknown.

Sudden hearing loss is determined through the process of elimination. Your ear-nose-throat specialist can use ear microscopy and a hearing test to establish whether you have sudden hearing loss or another illness. Blood pressure measurement, blood tests, an ultrasound or MRI can also help to obtain clarification.

A specialist can use an otoscopy to exclude external characteristics, such as obstructions and injuries in the ear canal. With hearing tests (tuning fork test, pure-tone audiometry), the doctor can determine the extent and localisation (inner or middle ear) of the hearing impairment. A doctor can best determine the classification of sudden hearing loss into a high-, mid- and low-frequency or pan-cochlear sensorineural hearing loss by performing a pure-tone test during the diagnostic process.

A patient’s medical history is an important diagnostic component. These records contain information that may indicate sudden hearing loss and its possible cause. If the medical history does not reveal any specific reasons for the sudden hearing loss, other diagnostic methods can be used, including the Fowler’s pure-tone audiometry, brain-stem-evoked response audiometry (BERA), or the measurement of otoacoustic emissions (OAE). These examinations serve to exclude a diseased acoustic nerve as the cause of impaired hearing.

The word pan-cochlear is divided into two terms: ‘pan-’ (meaning all-inclusive) and ‘cochlea’ (the spiral cavity of the inner ear). Pan-cochlear sensorineural hearing loss is, therefore, a hearing impairment which affects the entire cochlea.

During the Fowler test, sounds are sent alternately to both ears. The volume level varies and is adjusted with the help of the person being examined (subjective hearing test) until he or she can hear equally well with both ears. Alignment with the healthy ear serves to determine the audibility threshold and the extent of hearing loss.

This test measures the sound vibrations travelling from the brainstem to the cerebral cortex. If vibrations can be measured in the cerebral cortex, it’s usually assumed that the cochlea is not affected. This method assesses hearing impairment regardless of the affected person’s subjective impression (objective hearing test).

Blood supplies the inner ear with the required nutrients. If circulation is inhibited, the sensory hair cells of the ear are permanently damaged. Circulation can be improved by administrating circulation-enhancing medication, which can also include cortisone to prevent swelling (anti-oedema treatment).

The local anaesthetics procaine and lidocaine are frequently used to treat sudden hearing loss (inotropic therapy). Their administration blocks nerves that potentially lead to vascular constriction. This treatment should always be observed by a doctor.

Persistent hearing loss, combined with tinnitus, should be treated with hearing aids that can generate a soft noise to distract from unpleasant tinnitus symptoms.

Another treatment option is hyperbaric oxygen therapy (treatment in an oxygen pressure chamber). This is a good method of treatment, but according to the criteria of evidence-based medicine, it may not be the most effective.

Dialysis (apheresis) is another treatment option if the sudden hearing loss is particularly severe. This procedure is called heparin-induced extracorporeal low-density lipoprotein precipitation (HELP) apheresis, and ‘cleanses’ the blood of coagulation-promoting substances. This improves flow characteristics and circulation. Severe cases require inpatient treatment, but outpatient treatment by a specialist is usually possible.

Treating risk factors for arteriosclerosis (the build-up of fats, cholesterol, and other substances in the artery walls) is extremely important in the long run. Lifestyle changes that can facilitate treatment include weight loss combined with a low-fat diet and exercise, the correct adjustment of blood sugar levels, and avoiding nicotine, coffee and alcohol. Implementing these changes is imperative for effective treatment.

Alternative forms are available. However, their efficacy has not yet been proven and traditional health care professionals have, in some cases, rejected them.