What is sensorineural hearing loss?
Do you know what sensorineural hearing loss, or SNHL for short, is?
What causes SNHL?
Is SNHL treatable?
Doctors classify 90% of adult hearing loss as a result of damage to the structures inside the ear or damage to the auditory nerve under the set of sensorineural hearing loss.
In this article, you are going to read more about sensorineural hearing loss or SNHL sensor.
Sometimes a person suddenly develops SNHL, it can be said that this complication is one of the medical emergencies that leads to many ambiguities and inconsistencies for otolaryngologists or ENT specialists.
In these cases, a person goes to the doctor and says that when he woke up in the morning, he noticed that one of his ears could not be heard.
Or, for example, someone says that during the day when he was awake, he experienced a little dizziness or sometimes a slight tingling or a feeling of fullness in his ears, and then he lost his hearing.
What is the cause of this complication?
The underlying cause of SNHL is sudden, unknown, and obscure. Most cases of sudden SNHL are unilateral and bilateral is very rare.
Doctors say that a condition in which a person’s hearing is suddenly deaf is an emergency case and should be referred to a doctor or specialist immediately.
Anatomy of the human ear
Before addressing the causes and symptoms of SNHL, it is best to know a little about the structure inside the ear to make it easier to understand the following concepts:
The human ear is divided into three parts:
- External ear
- Middle ear
- Inner ear
The sound enters the external ear canal from the entrance of the ear, enters the eardrum and is transmitted to the middle ear by the tympanic membrane and is amplified by the middle ear bones and enters the inner ear area after passing through the oval and round valves.
In the human inner ear are semicircular or cochlear ducts that play a role in both balance and hearing. In the spiral organ of the inner cochlea, there are a number of very delicate lashes that doctors call Stereocillia.
It is said that when vibrations reach the inner ear, it causes these lashes to shake. The vibration of these very delicate hairs at the base is converted into nerve signals and transmitted to the brain by the ear nerve so that we can perceive them as sounds.
If the ear is exposed to sounds higher than eighty-five decibels, these very sensitive hairs will be damaged.
Doctors say that in order for a person to have hearing loss, 30 to 50 percent of these fine hairs in the cochlea must be damaged. It is said that the sound of heavy traffic and crowds in the city that you hear from inside your car is equivalent to eighty-five decibels.
In the following, we will talk about the sudden and one-sided normal hair loss sensor and also about SNHL in the elderly
If SNHL is unilateral and has gradually developed and progressed, it may not be detected without audiometry or audiometric testing.
And so to speak, the person himself has little sign.
But a person may suddenly experience noticeable hearing loss in one ear. Generally, these people realize one morning after waking up that they do not have one ear or hear very little.
One or more of the following symptoms may be present:
- The person is not able to hear a particular sound in the presence of background sounds
- The person says that he hears sounds but cannot understand them.
- One in particular cannot hear and understand the voices of women and children
- People’s voices and speech become vague to him
- Ringing in the ears
- Difficulty maintaining balance
- The main problem with SNHL is the inability to hear and perceive high-frequency sounds or low-pitched sounds.
What could be the cause of the sensorineural hearing loss?
This complication can be congenital, and it exists from birth. One in three babies are born with hearing loss. Congenital hearing loss is said to be one of the most common birth defects.
Fifty percent of these babies have hearing loss due to genetic problems. Doctors say there are more than 100 known genetic disorders for congenital hearing loss.
Another 50 percent have hearing problems due to acquired causes.
Infections and lack of oxygen (fetal asphyxia) are acquired causes of sudden hearing loss or hearing loss at birth.
There are two major categories of SNHL causes
- Audio traumas:
It means facing loud noises
Chronic exposure to noise over eighty-five decibels, for example, in constant traffic and urban congestion or even a single shot or explosion can lead to irreversible deafness.
Aging-related hearing loss is called Presbycusis
Fifty percent of people aged seventy-five are said to experience some form of hearing loss
One in three people between the ages of sixty-five and seventy-four is deaf.
Types of hearing loss
Depending on the degree of damage, hearing loss is divided into the following three categories:
- Mild hearing loss: Decrease in hearing between 26-40 decibels
- Moderate hearing loss: Decrease in hearing between 41-55 decibels
- Severe hearing loss: More than seventy-one decibels
Lack of management and control of SNHL will not cause life-threatening conditions but will reduce the quality of communication between the affected person and others and the community.
Other possible causes
The specific causes for sudden hearing loss have not yet been identified, and in other words, “unknown cause” is the most common cause!
There are theories that the virus or circulatory disorder in the ear may cause sudden SNHL.
The following causes can also cause sudden hearing loss:
- Causes of infection:
- Infectious meningitis
- Lyme disease
- Acoustic neuroma or vestibular schwannoma
- traumas to the head
- Immune system problems
- Immune system problems; Sarcoidosis
- Meniere’s disease
- Multiple sclerosis
- Drugs that damage the hearing system
A history will be obtained by visiting a doctor, your medication list will be recorded, and a clinical examination will be performed.
Audiometry is required
Ear tape will only identify the type of hearing loss
Damage to buildings related to the ear nerve causes SNHL, and problems with the sound path from the ear canal to the inner ear can cause conductive hearing loss, or CHL.
These two important categories create quite distinct and different characteristics in the ear canal
Sometimes it is necessary to use CT scan or MRI and etc. in addition to hearing tests.
The treatment plan will be selected based on the cause of the SNHL.
In cases of acute and sudden onset of SNHL, corticosteroids are said to be the mainstay of treatment.
Antiviral drugs are sometimes taken, but their effectiveness has not yet been proven. The most important treatment is early diagnosis and early treatment.
Doctors say that if twenty to thirty days elapse between the sudden onset of SNHL and the start of treatment, the effect of treatment will be greatly reduced.
Corticosteroids are started orally and sometimes hospitalization and intravenous corticosteroid injection are required.
Sometimes there are people for whom the doctor cannot use oral or injectable corticosteroids. For these people, treatment will be by injection into the ear.
For example, in people with hypertension or diabetics and people with a history of gastrointestinal ulcers and gastric and intestinal ulcers.
In cases where oral corticosteroids are started, after ten days, the hearing and audiometry tests must be performed again, and based on the test results, it is recommended to continue oral treatment or injecting into the ear.
The most important point in the treatment of SNHL is the time of referral and the time of starting treatment
The longer the day between the onset of sudden SNHL and the day and time of treatment initiation, the less successful the treatment will be.
So if you or your relatives suffer from the mentioned symptoms, especially suddenly, you should immediately go to the emergency room of the medical and specialized center.