Hearing loss: causes and treatment
What is the status of hearing loss?
Hearing loss is a common medical condition, which occurs for various reasons such as old age, exposure to excessive noise or infection with a disease that may affect the sense of hearing and consequently a person’s life.
Research indicates that there are more than 5% (432 million adults 34 million children) of the world’s population suffer from hearing loss, and the same study predicts that by 2050 the number of people with hearing impairment will increase to more than 700 million people.
Hearing loss does not occur suddenly but gradually, starting from mild hearing problems, to a complete loss of hearing in the advanced stages, when the stages are as follows:
- Mild hearing loss where the patient has certain difficulties in communicating with the people around him.
- The condition regresses to mild hearing loss, and patients at this stage can communicate with the environment with little trouble understanding spoken speech or surrounding sounds.
- The condition may worsen and the hearing loss becomes severe, and the person is unable to hear, without hearing aids (hearing aids) or cochlear implants.
- Finally, the patient reaches a stage of hearing loss, and some advanced cases can benefit from hearing aids (hearing aids) or cochlear implantation.
The hearing mechanism must first be explained in order to understand the classification mechanism of hearing loss and the causal factors, which are as follows:
- outer ear: The sound waves enter through the external auditory canal, and hit the eardrum, which vibrates according to the sound signals.
- middle ear: The vibrations are transmitted from the eardrum to the auditory ossicles, which in turn transmit the waves to the inner ear.
- inner ear: The vibrations reach the part responsible for hearing, which is the cochlea in the inner ear, which contains the organ of Corti, which is responsible for converting motor vibrations into a nerve impulse, which is transmitted through the auditory nerve to the brain which interprets sound.
Types of hearing loss
Hearing loss can be classified into three main categories depending on the location of the injury that caused the hearing loss, and the types include:
Conductive hearing loss
In this case there is a reason that prevents the sound waves and vibrations from reaching the inner ear, so the responsible cells will not receive a warning.
The problem can be in the outer or middle ear, and conductive hearing loss is often treated with surgery or medication.
2- sensorineural hearing loss
The problem is in the inner ear, and it can be in the cells responsible for receiving vibrations or turning them into nerve stimulation, or even a problem with the nerve itself.
This is the most common type of hearing loss, sensorineural hearing loss cannot be treated with medicine or surgery, but the patient can be helped to hear with hearing aids.
3- Mixed hearing loss
It is the occurrence of hearing loss, both from conductive and sensorineural causes at the same time.
Hearing loss causes
The reasons that can lead to hearing problems or even loss are diverse, and are divided according to the previous classification as follows:
1- Sensorineural hearing loss
This type of hearing loss has many causes, including:
A- Acquired sensorineural hearing loss
Acquired hearing loss occurs after birth, later in a person’s life, and causes include:
- Advanced age: Presbyopia Sensorineural hearing loss is one of the most common causes, and because this type of bilateral hearing loss affects both ears, the patient may not notice the hearing loss occurring over time.
- Noise: Hearing loss may occur due to continuous exposure (for a long time) to sounds higher than 85 decibels, and there is a gradual decrease in hearing and the patient may experience additional tinnitus.
- infection: Bacterial meningitis is an important risk factor, and according to some studies, 10% Among the patients with meningitis suffer from a hearing disorder, which may become permanent damage.
- Viral infection is a common cause of hearing loss, as it causes 40% Among the cases of acquired hearing loss, cytomegalovirus (CMV) is the most common virus that causes, in addition to rubella and measles.
- Brotrauma: Exposure to a loud and sudden sound can cause hearing loss on one or both sides. This condition is often seen when exposed to the sounds of artillery and jet engines.
- trauma: Certain head trauma, leading to skull fractures, may be associated with damage to the inner ear.
- Tumors: Some ear tumors can affect the function of the inner ear, including acoustic neuroma and cholesteatoma, a condition that occurs in the middle ear and may spread to the inner ear.
- Medicines: There are many medications that may have a negative effect on the inner ear, but the most important of them are:
- Antibiotics such as gentamicin
- Nonsteroidal anti-inflammatory drugs, such as aspirin
- Cancer chemotherapy
- Other disorders: Research has revealed the association of some thyroid diseases, such as hyperthyroidism or hypothyroidism, with sensorineural hearing loss. (1)
- Another report indicated that hearing loss is associated with some autoimmune diseases such as systemic lupus. (2)
b Congenital sensorineural hearing loss
Hearing loss during pregnancy is rare, but it is nevertheless recommended to check newborns, correct hearing problems, and the most important reasons include:
- Premature babies (babies born before the ninth month)
- Infections that the mother may contract during pregnancy and be transmitted to the fetus, such as German measles
Conductive hearing loss
They are congenital or acquired factors.
The congenital causes of this condition include abnormalities in the structure of the outer or even the middle ear, which may affect the function of the ear and its ability to hear.
Acquired causes include:
- Middle ear infection: in its various forms, which is a common cause of conductive hearing loss.
- Fluid accumulation in the ear: As a result of colds, or even allergies, or as a result of problems with the work of the Eustachian tube, which is a canal connecting the middle ear to the nasopharynx, and if blocked, fluid will accumulate in the middle ear. without leaking through the channel itself.
- Sclerosis of the middle ear: Also known as stapes sclerosis, this is a common genetic condition, especially in middle-aged women, in which there is a decrease in the movement of the bones that transmit vibrations, which causes difficulty in hearing.
- hearing loss: For example, if pebbles enter the outer ear, or cerumen collects and blocks the tube.
- Ear Infection: The infection can affect the outer ear and is known as swimmer’s ear.
- Perforation of the eardrum: Something that can happen as a result of any pressure trauma or due to an otitis media, for example.
Risk factors for hearing loss
Studies on hearing disorders have confirmed the presence of several risk factors, the presence of which increases the possibility of hearing damage, as follows:
- smoke: The harmful effect of smoking can affect and damage hearing, and it is assumed that smokers have a higher risk 70%Decreased hearing compared to non-smokers.
- diabetic: Uncontrolled diabetes, with a persistently high blood glucose value, has a negative effect on hearing by 30%Even people with pre-diabetes are more likely to have hearing problems.
- hypertension: A higher arterial pressure value is associated with an increased hearing threshold, so patients with untreated hypertension are at greater risk of hearing loss later in life.
- Cardiovascular disease: There is a link between cardiovascular disease and hearing disorders and it is suggested research in 2021 The problems with the blood supply in the cochlea are responsible for the lack of sensory-neural hearing that occurs.
Signs of hearing loss
The patient may not notice that he is suffering from hearing loss, especially if it occurs gradually and over several years, but there are several signs that the patient’s friends may feel, as follows:
- Difficulty interacting and talking on the phone
- Inability to follow a conversation well, especially if it is between two or more people
- The victim often asks to repeat the speech several times
- Turn up the volume on the TV, radio or phone to be heard
- Difficulty understanding the speech of children and women
- Hearing decreases with every light noise
Hearing loss diagnosis
What is more important than discovering a hearing loss, is knowing the type of hearing loss that occurred, and then the reason that led to it.
The doctor will take the history and some diagnostic tests during the clinical examination, and may start other additional tests.
The steps are as follows:
1- The medical history
The doctor asks about several important points, using several questions, such as:
- When did hearing problems first appear?
- One sided or two sided?
- Working conditions and exposure to noise?
- What medications is the patient taking?
- Are there comorbidities?
- Is there a family history of hearing loss?
- Is there a history of frequent ear infections?
2- Clinical examination
The clinical examination plays an important role in hearing loss and is performed by an otolaryngologist. The examination covers all instruments and is in the following order:
- The doctor usually starts by looking for any abnormalities in the outer ear.
- He then uses an otoscope, which is a device equipped with a light and a magnifying lens, through which the doctor can observe the auditory canal and make sure there is any mass, in addition to examining the eardrum.
- He also uses the tuning fork tests, which is a U-shaped metal tool, this tool vibrates when struck, and is placed on specific places of the head, depending on the test being used. He was able to clearly distinguish conductive hearing loss from sensorineural or mixed hearing loss.
3- Additional checks
There are several tests that provide information about the function of the middle ear, inner ear, and auditory nerve, including:
- Audiogram: Called pure audiometry (PTA), the patient sits in a soundproof room and wears headphones connected to the testing device, which gives different intensities and frequencies.
- The doctor asks the patient to raise his hand or give him any signal when hearing specific sounds, and based on the signals the doctor can reach the location (conductive or central) of the defect.
- Brain stem mapping (ABR): This test is usually used for babies, in order to detect problems that may be hidden after birth. Electrodes are placed on the patient’s head, and the chart is monitored in response to the applied sounds.
- This test examines the nerve pathways of the ear, from the inner ear to the brain stem and brain.
- Otoacoustic transmission (OAE): It is used if the defect is directed to the inner ear, as it helps to evaluate the cochlea, especially the hair cells in the organ of Corti.
- This test depends on the insertion of a probe that emits a set of sounds and then measures the sounds returned from the cochlea, from which the doctor creates a clear picture of its function.
- Magnetic resonance imaging (MRI): The doctor uses an MRI to examine the structure of the inner ear and the surrounding structures.
- Especially if the hearing loss is unilateral, and the tests are aimed at sensory neurological factors, in order to rule out the presence of an acoustic neuroma.
- Computed tomography (CT): A CT scan is preferred if the type is conductive, as it helps detect any damage to the bony components of the ear or abnormal bone growth in the middle ear (sclerosis stapes).
Treatment of hearing loss
The sense of hearing plays an important role in supporting a person in daily tasks from simple to complex, therefore the treatment of hearing impairment has an especially important role in the childhood stage, due to its important role in this stage to develop language and social skills.
1- Treatment of sensorineural hearing loss
The occurrence of damage to the inner ear is usually permanent, so no treatment method will work, and the treatment depends on improving the auditory method through hearing aids or applying for a cochlear implant.
A- Hearing aids
Hearing aids do not treat or restore hearing loss, but rather amplify the incoming sound, and the doctor adjusts the device according to the degree of the condition to help the patient distinguish between sounds as much as possible.
There are different shapes and styles of these devices, which are usually placed behind the ear, and can be installed inside the ear, depending on the degree of hearing loss. The doctor may install devices in both ears if necessary.
These devices give the greatest benefit in mild to moderate degrees of hearing loss, but they will not be able to provide sound at its natural pitch.
B – Cochlear implantation
For people who have not received an acceptable response from hearing aids, cochlear implants are a good option for sound amplification.
This is a surgical procedure that is not dangerous and can be performed on children, adults and even the elderly.
2- Treatment of conductive hearing loss
This type of hearing loss responds well to treatment, and the problems leading to hearing loss are often temporary, and the patient’s hearing ability improves as the condition improves, such as middle or even outer ear infections.
The doctor may resort to therapeutic procedures such as extracting the wax stuck in the auditory path or transplanting the eardrum in case of a hole in it.
If fluid collects behind the eardrum, the doctor may also puncture the eardrum to place a tube to drain the fluid.
The doctor may turn to the surgical option even if there is an anatomical problem that inhibits the transmission of sound to the inner ear, such as the presence of a congenital anatomical defect that can be corrected.
Tips for preventing hearing loss
The damage that leads to hearing loss is permanent, so it is crucial to follow preventive measures. This includes:
- Stay as far as possible from places of noise, and is the most important step to keep your ears safe.
- Wearing earplugs, especially for loud parties, can help prevent.
- It is better to take a break in a quiet place after any noisy event.
- The duration of wearing the headphones should not exceed more than an hour a day.
- When wearing headphones, keep the volume below 60%.
- Check with an otolaryngologist regularly, especially when one of the previously mentioned risk factors is present.
Tips for maintaining a healthy ear
There are several tips related to the general health of the ear, and they are:
- Avoid inserting foreign material into the ear, as the lining of the auditory canal is sensitive and may be damaged.
- Avoid cleaning the ear with cotton wool, as this will push the wax in, making it difficult to remove.
- Wash the ear flap (and the space behind the ear) with a little soap and water, and dry well afterwards.
- A drop of olive oil can be used once or twice a week to help soften the wax, making it easier to remove.