Brief overview
- Definition: Sudden, usually unilateral hearing loss without a recognizable trigger, a form of sensorineural hearing loss
- Symptoms: Reduced hearing or complete deafness in the affected ear, tinnitus, feeling of pressure or absorbent cotton in the ear, dizziness, furry feeling around the pinna, possibly hypersensitivity to sound
- Causes and risk factors: The exact causes are unknown, possible triggers and risk factors are inflammation or circulatory disorders in the inner ear, autoimmune diseases, obesity, diabetes mellitus, high blood pressure, smoking, stress, emotional strain
- Treatment: Cortisone (usually as a tablet or infusion, sometimes as an injection into the ear), no treatment is often necessary for mild sudden hearing loss
- Prognosis: Favorable if the sudden hearing loss is only mild or only affects the low or medium frequencies, otherwise the prognosis worsens. It is also unfavorable if the sudden hearing loss is accompanied by severe hearing loss and/or balance problems.
- Diagnosis: Taking a medical history, ear, nose and throat examination, various hearing tests
- Prevention: Avoiding risk factors such as smoking and stress as well as regular medical check-ups for illnesses such as diabetes mellitus reduce the risk of sudden hearing loss, but it is not possible to prevent it with certainty
What is sudden hearing loss?
True sudden deafness is a form of sensorineural hearing loss. In the cochlea of the inner ear, the amplified sound waves transmitted via the middle ear are converted into electrical nerve signals. From there, they reach the brain and thus the conscious mind. In the case of sudden hearing loss, the signal conversion in the cochlea is disturbed.
In principle, sudden hearing loss occurs at any age and in all genders. However, they are very rare in children. Most of those affected are around the age of 50.
Forms of sudden hearing loss
A sudden hearing loss can be classified according to its severity: Mild sudden hearing loss causes only mild hearing loss, whereas severe forms can cause hearing loss and even deafness on the affected side.
Secondly, cases of sudden hearing loss are classified according to the frequency range affected: In the cochlea, different sections are responsible for different frequencies during signal conversion. Low, medium or high tones are therefore processed in separate areas. If only one of these areas is affected in a sudden hearing loss, this leads to the following forms of the disease:
- High-frequency hearing loss
- Mid-range hearing loss
- Low-frequency hearing loss
Hearing loss: symptoms
The typical sign of sudden deafness is a sudden and painless loss of hearing. Depending on the form and severity of the disease, the patient may perceive certain pitches more poorly or not at all with the affected ear.
The sudden hearing loss is often accompanied by other symptoms, which sometimes precede the hearing loss as a kind of warning sign:
- Tinnitus (ringing in the ears)
- Feeling of pressure or absorbent cotton in the ear
- dizziness
- Furry feeling around the auricle (periaural dysesthesia)
Hearing ability after a sudden hearing loss is not always simply reduced. Sometimes other disorders occur instead of hearing loss or in addition to it. For example, some patients perceive sounds and noises on the affected side as excessively loud. This hypersensitivity to sound is called hyperacusis.
Other patients report an altered perception of sound (dysacusis). Sometimes sounds on the diseased side are perceived lower or higher than on the healthy side (diplacusis). Pain is not a typical symptom of sudden hearing loss and is usually triggered by other things, such as the feeling of pressure in the ear that sometimes accompanies sudden hearing loss.
Those affected sometimes do not even notice a slight hearing loss. It is then often only noticed during certain hearing tests. However, if it is severe, the symptoms of sudden hearing loss often severely impair quality of life.
Hearing loss: causes and risk factors
The causes of sudden hearing loss are not yet known. However, experts suspect that the following factors are among the triggers for sudden sensorineural hearing loss:
- Circulatory disorders of the cochlea
- Malfunction of certain cells in the cochlea
- Inflammation of the inner ear
- Autoimmune diseases
- Endolymphatic hydrops (abnormal increase of a certain fluid in the inner ear)
Endolymphatic hydrops is not considered a true hearing loss by many ENT specialists. It is caused by a build-up of natural inner ear fluid and usually affects the low sound frequencies in isolation. It usually disappears spontaneously within a short time and therefore does not require any special treatment.
Circulatory disorders in the inner ear are sometimes caused by problems with the (cervical) spine, which in these cases are the indirect cause of sudden hearing loss.
People who suffer from migraines have an increased risk of sudden hearing loss.
Other causes of acute hearing loss
Acute hearing loss is not always caused by a real hearing loss. The following causes also sometimes trigger a spontaneous hearing loss:
- Foreign body or water in the ear
- Blockage of the external auditory canal or eardrum due to “earwax” (cerumen)
- Injuries to the eardrum or ossicles in the middle ear
- Accumulation of fluid, bleeding or suppuration in the middle ear
- Unbalanced pressure difference between the middle ear and the external auditory canal (lack of pressure equalization, for example on an airplane)
Is a sudden hearing loss: When to see a doctor?
A sudden hearing loss is not considered an emergency that requires immediate medical treatment. How urgent a visit to the doctor is depends on the severity of the hearing loss, any accompanying symptoms and previous illnesses as well as the patient’s individual level of suffering. In most cases, sudden hearing loss is treated on an outpatient basis or at home.
Only in severe cases or if the hearing loss progresses are patients admitted to hospital for treatment.
Hearing loss: examinations and diagnosis
When the first signs of sudden hearing loss appear, a visit to the doctor is advisable. An ENT specialist will determine the extent and type of hearing loss and rule out other possible causes for the acute hearing loss.
This is followed by a general ear, nose and throat examination (ENT examination). Using otoscopy (ear microscopy), the doctor examines the ear canal and the eardrum for any damage.
A hearing test is also important: in the Weber test, the doctor strikes a tuning fork and places it on the top of the patient’s head. The patient is then asked to indicate on which side they hear the sound of the vibrating tuning fork louder.
During the hearing test using tone audiometry, the ENT doctor plays sounds at different frequencies to the patient (via loudspeakers or headphones). The volume is then gradually reduced until the patient can just barely hear the sound in question (“hearing threshold”). A hearing curve (audiogram) produced in this way can be used to show which frequency range the hearing loss affects and how pronounced it is.
During tympanometry, a special probe is inserted into the external auditory canal to check the function of the middle ear. Routine examinations for (suspected) hearing loss also include a test of the sense of balance and a blood pressure measurement.
Further examinations
In individual cases, further examinations are useful to clarify a possible sudden hearing loss.
For example, the function of the inner ear can be checked by measuring otoacoustic emissions (OAE).
To rule out a specific tumor in the brain (cerebellopontine angle tumor) as the cause of hearing problems, magnetic resonance imaging (MRI) is sometimes necessary.
Hearing loss: treatment
As the actual causes of sudden hearing loss are not known, there is no causal therapy for sudden hearing loss. However, some treatment options are known to be somewhat effective for sudden hearing loss (drugs such as prednisolone or other “cortisones”). Although there are other methods, their effectiveness is disputed among experts.
Hearing loss during pregnancy is rare, which is why there is no standard treatment for pregnant women. Due to the possible impairment of the unborn child, treatment is discussed in detail with the doctor in advance.
Tip: Every patient should seek advice from their doctor about the various options and risks of acute hearing loss treatment. They will then decide together which treatment seems most promising in the individual case.
A mild sudden hearing loss that hardly affects the patient is not necessarily treated. Sometimes you wait a few days – in many cases, a sudden hearing loss spontaneously resolves on its own. However, it is not possible to predict if and when this will happen in individual cases.
Hearing loss: treatment options
Cortisone
High doses of glucocorticoids (“cortisone”), such as prednisolone, are primarily recommended for the treatment of acute sudden hearing loss. The active ingredients are usually administered as tablets or infusions over several days. The dosage is based on the current guidelines of the respective country.
Because medication is generally effective throughout the entire body when administered as a tablet or infusion, this is referred to as systemic therapy. There is a possibility that side effects may occur in different areas of the body, such as increased blood sugar levels.
If systemic cortisone therapy does not help sufficiently, there is the option of injecting the cortisone directly into the ear (intratympanic application). In this case, the medication practically only has a local effect, which avoids systemic side effects. However, there is a risk of other consequences with this cortisone application directly in the ear, such as pain, dizziness, injury to the eardrum (eardrum perforation) or inflammation of the middle ear.
Experts believe that the effectiveness of glucocorticoids for sudden hearing loss is due to the anti-inflammatory and decongestant properties of the medication.
Oxygen therapy
Other medications
Medication that dilates the blood vessels (vasodilators) or improves the flow properties of the blood (rheologics) is sometimes recommended for sudden hearing loss. However, due to the lack of proof of efficacy and the possible side effects, such preparations are no longer recommended by the professional associations for the treatment of sudden hearing loss.
The same applies to antiviral drugs such as acyclovir, which are also sometimes offered for the treatment of sudden hearing loss. No benefit of this treatment has been found in studies to date. For other alternative treatment methods such as acupuncture or homeopathy, there is also no evidence of effectiveness to date.
Surgery
In the case of complete hearing loss or severe hearing loss, a cochlear implant is considered. After the hearing loss, a small device is inserted as part of an operation, which transmits the sounds from a receiver on the outside of the ear to the auditory nerve on the inside. The “receiver” looks similar to a conventional hearing aid.
Home remedies for sudden hearing loss
Soothing teas can be used as a home remedy to reduce stress. However, they do not help against the sudden hearing loss itself.
Rest and stop smoking
Experts generally recommend plenty of rest after a sudden hearing loss. Apparently, stress plays an important role in its development. This is why patients with sudden hearing loss are usually put on sick leave by their doctor for some time and should not return to work immediately after a sudden hearing loss.
Sport is generally possible after a sudden hearing loss. However, it is important to ensure that:
- The sport does not strain your ears (as is the case with pressure equalization during diving, for example)
- The sport does not cause you any additional stress
- The symptoms of the sudden hearing loss would not lead to an increased risk of injury (such as dizziness and balance problems)
As smokers have an increased risk of sudden hearing loss, it is highly advisable to give up nicotine completely, i.e. to stop smoking, in addition to resting.
Hearing loss: course of the disease and prognosis
The course and prognosis of sudden hearing loss depend heavily on how severe the hearing loss is at the beginning, whether it worsens and in which frequency range the hearing loss occurs:
- The most favorable prognosis is for a hearing loss that only affects the low or medium frequency range or is only accompanied by a slight hearing loss.
- If the hearing loss progresses further, the prognosis worsens.
- The prognosis is usually unfavorable in patients whose hearing loss is accompanied by balance disorders.
It is not possible to predict how a sudden hearing loss will progress in individual cases. The same applies to the duration of the hearing loss. In principle, a mild hearing loss in particular often heals spontaneously on its own after a few days. A severe hearing loss, on the other hand, is often followed by long-lasting or even lifelong hearing problems (hearing loss).
Hearing loss: risk of relapse
Patients with sudden hearing loss have an approximately 30 percent risk of suffering another sudden hearing loss sooner or later (recurrence). People with existing risk factors such as high blood pressure or persistent stress are particularly at risk. In addition, patients with a sudden hearing loss in the low or medium frequency range are particularly prone to relapses.
Hearing loss: prevention
It is not possible to prevent sudden hearing loss with certainty. However, you do have the opportunity to reduce your personal risk. If possible, avoid risk factors such as smoking and stress.
If you have diabetes mellitus, for example, make sure you have regular medical check-ups with your doctor.
