What is sudden hearing loss?
Just as the name implies, this type of hearing loss can occur suddenly or develop within a few hours. It affects the inner ear, the effects range from mild to severe and can become permanent. It’s also called sudden sensorineural hearing loss (SSHL). This is a serious condition, and we highly recommend you contact your doctor immediately if you develop symptoms.
What are the symptoms of sudden hearing loss?
Sudden hearing loss usually occurs in one ear without a trigger or recognisable cause. Earache is not a symptom of sudden hearing loss and may point to something else, like an infection. The following symptoms may accompany this type of hearing loss:
- Loss of sensation in the outer ear
- Ear pressure
Ear pressure and tinnitus (ringing in the ear) may occur simultaneously. People who experience dizzy spells are sometimes also diagnosed with cardiovascular problems. Further symptoms may include a dissociation effect when listening to music or familiar voices.
Experts attribute the cause of sudden hearing loss to an impaired blood supply in the cochlea of the inner ear:
Is sudden hearing loss the same as tinnitus?
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.
What causes sudden hearing loss?
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:
- 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.
Sudden idiopathic hearing loss
Idiopathic means “without recognisable cause”. This is the most common type of sudden hearing loss. An extensive examination cannot determine an organic cause.
Stress-related sudden hearing loss
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.
How is sudden hearing loss diagnosed?
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.
What is pan-cochlear sensorineural hearing loss?
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.
How does the hearing test work?
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.
How does brain-stem-evoked response audiometry (BERA) work?
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).
How is sudden hearing loss treated?
Time is of the essence and the earlier it gets treated, the better the prognosis. In a best-case scenario, sudden hearing loss is treated by a specialist or a clinic within the first 24 hours. More than two-thirds of patients recover fully. But if your hearing continues to deteriorate or if additional balance disorders occur, it may result in a poor prognosis. Some people experience permanent hearing loss and/or tinnitus to varying degrees. Here are the most common forms of treatment:
Circulation-enhancing (rheological) medication
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).
Treatment with local anaesthesia to block inhibited nerves
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.
Treatment in an oxygen pressure chamber
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.
Treatment for particularly severe cases of sudden hearing loss
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.
Treatment in the event of obesity and diabetes
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 of treatment
Alternative forms are available. However, their efficacy has not yet been proven and traditional health care professionals have, in some cases, rejected them.
Can hearing aids help?
If symptoms persist for a long time and have already led to a hearing deficit, only hearing aids can provide effective relief. A hearing aid can drastically improve your quality of life. If sudden hearing loss occurs together with tinnitus, a hear.com expert can recommend a hearing aid with special functions to reduce tinnitus.
Treatment following sudden hearing loss
Shortly after sudden hearing loss, the focus is on reducing risk factors, especially cardiovascular risk factors like obesity, high blood pressure, high cholesterol levels and diabetes. You need to take steps to ensure that your lifestyle is less stressful to prevent situations that are difficult to cope with. Exercising regularly may be helpful. If the sudden hearing loss occurred more than a year ago and has led to permanent hearing loss of any degree, the only option is to alleviate it with the help of a hearing aid.
Complications following sudden hearing loss
Sudden hearing loss may result in several complications that reduce hearing capacity. There is always the risk of hearing impairment or even complete deafness. Depending on your circumstances, it can be short-term or permanent. A possible long-term effect is the development of tinnitus (a buzzing or ringing of various tones in the ear) after sudden hearing loss. This may be accompanied by a feeling of pressure in the ear. In some cases, sudden hearing loss is followed by restlessness and a racing heartbeat.