Hearing loss (or hearing loss) Hearing loss, in which the sound signals do not reach the brain correctly: it occurs when part of the ear or hearing system does not function normally.
Contents
Types of hearing loss
1) Conductive hearing loss – Any disorder in the outer or middle ear that prevents proper sound conduction is known as “conductive or conductive hearing loss.”
They are light or moderate, between 25 and 65 decibels, and can also persist temporarily.
2) Sensorineural hearing loss – Caused by:
- a loss or lesion of sensory hair cells in the cochlea, but can also be caused by
- damage to the auditory nerve
It is usually profound and lasting.
The sound usually reaches the inner ear, but here the above-mentioned disturbances do not allow the acoustic information to reach the higher-level nerve centers. This is also known as “sensorineural hearing loss” and can:
- mildly,
- moderate
- intense
- be profound.
Often these patients use a hearing aid or are equipped with an implantable hearing aid for the middle ear.
3) Perceptual hearing loss – It occurs when there is a malfunction in the hearing apparatus, which receives and processes the nervous signals in the brain.
4) Combined hearing loss – Hearing loss is both conductive hearing loss and sensorineural hearing loss.
Combined hearing loss – Hearing loss is both conductive hearing loss and sensorineural hearing loss.
Classification of hearing loss
Hearing loss can also be divided into degrees:
- Mild hearing loss (hearing loss between 20 and 40 decibels) – The patient with mild hearing loss hears most of the speech, but soft and bright sounds are difficult to perceive.
- Moderate hearing loss (40-70 dB) – The patient with moderate hearing loss has great difficulty understanding a person who speaks normally.
- Profound hearing loss (70-90 dB) – These patients do not understand what a person is saying with their normal voice and only hear some loud noises.
- Residual hearing loss (> 90 dB) – The patient with residual hearing does not perceive speech, but only isolated very loud noises.
Hearing loss can occur as follows:
Monolateral or bilateral
hearing loss is monolateral if it occurs only in the left or only in the right ear.
Bilateral hearing loss occurs when both sides are affected.
Prelingual and postlingual
hearing loss is called prelingual when it is diagnosed in a person before they have learned to speak. It is called postlingual if it was diagnosed afterwards.
Symmetrical and asymmetrical
Hearing loss is identical in both ears or different in each ear: depending on this, it is referred to as symmetrical or asymmetrical hearing loss.
Progressive or sudden
Hearing loss worsens as it progresses or occurs quickly and suddenly.
Fluctuating or stable
The hearing loss improves or worsens over time, or it is stable and always consistent.
Congenital or acquired/delayed in origin
Hearing loss has existed since birth or occurs later in the patient’s life.
Causes of hearing loss
Advanced age and loud noises are the most common causes of hearing loss.
Age is the most common cause of hearing loss: hearing loss increases with age, by the age of 80 most people have significant hearing problems.
Hearing loss in the elderly occurs when the hair cells in the cochlea gradually die or become more and more damaged: this type of hearing loss is called sensorineural or sensorineural hearing loss.
The first sounds that these people no longer perceive are the high-frequency (treble), such as voices of women and children, but hearing consonants also becomes more difficult. Sounds of lower frequency are heard more easily.
Another common cause of hearing loss is ear damage, which is caused by repeated loud noises over time: the hair cells inside the cochlea are injured, sensorineural hearing loss develops.
This can be observed in humans:
- who work with noisy machinery (occupational disease),
- who spend many evenings in a discotheque.
Sensorineural hearing loss can also be caused as follows:
- Genetic deafness – some people are born deaf or become deaf over time due to a genetic abnormality, even if it is not always familial.
- Viral infection of the inner ear – for example, mumps or measles
- Infection of the auditory nerve – caused by mumps or rubella viruses.
- Rhinogenic deafness – caused by inflammation of the upper respiratory tract (nose and throat). In children, it occurs together with tonsillitis or enlargement of the pharyngeal tonsils.
- Meniere’s syndrome – a person suffers from dizziness, tinnitus (ringing in the ears) and has the feeling of a swollen stuffy ear, while the hearing loss fluctuates over time.
- Usher syndrome – is a genetic disorder that leads to deafness, loss of vision and, in certain cases, severe balance disorders.
- Acoustic neuroma – is a benign tumor of the myelin sheath of the auditory nerve.
- Meningitis – is an infection of the protective membrane around the brain and spinal cord
- Labyrinthitis – is an inflammation of the labyrinth and semicircular ducts of the ear. It causes dizziness, hearing loss, vomiting, nausea and tinnitus.
- Encephalitis – is an inflammation of the brain.
- Multiple sclerosis – is a neurological disease that affects the central nervous system.
- Stroke – the blood supply to the brain is interrupted, the primarily sensitive hearing areas can be affected. Occlusion of the internal auditory artery can provoke mild hearing loss or ischemia of the labyrinth, leading to deafness.
Causes of conductive hearing loss are most often mechanical occlusions of the ear canal (for example, due to excess earwax), fluid accumulation or infection of the middle ear.
There are other rare causes of conductive hearing loss:
- Perforated eardrum – the eardrum is damaged or has a hole.
- Otosclerosis – this is an abnormal bone growth in the middle ear that leads to immobility of the stirrup and consequently to less effective sound conduction.
- Very rare are damage to the ossicles caused by a head injury (for example, a slap), a ruptured eardrum or a cholesteatoma (pearl tumor); this is an abnormal accumulation of epithelial cells in the middle ear.
- The constant use of headphones is a youth problem that exists nowadays.
In recent years, there has been an alarming increase in hearing loss among adolescents. The problem seems to have increased due to the increased and constant use of headphones worn to listen to music.
Usually, conductive hearing loss is only temporary and is treated with medication or minor surgical procedures.
Transient hearing loss
There are several causes that cause momentary hearing loss: most of them are reversible after appropriate therapy. Some of the most common are:
Earwax accumulation
The production of cerumen is a natural process, but sometimes the earwax accumulates in the ear canal and prevents the sound waves from reaching the eardrum.
Infections
of the middle ear They arise mainly when patients have a cold or fever: in such a state it is easily possible for catarrh to develop and affect the Eustachian tube that connects the ear and throat.
The result is a middle ear infection, in which there may be a rupture or sudden breakthrough of the eardrum, the patient has pain and can lose blood or pus from the ear.
Changes in pressure When traveling by plane, some people suffer from temporary hearing loss due to the differences in pressure between the middle ear and the atmosphere, as these cannot be compensated by the Eustachian tube.
Exposure to loud noises
Lesions. For example, an injury to the head or ear.
Other causes:
- Ear canal narrowing
- Surgical complications
- Foreign bodies or neoplasms in the ear
- Birth defects
Unilateral deafness
Hearing loss in one ear or “unilateral deafness” is a hearing disorder in which a person is able to hear normally with one ear but nothing in the other.
Deafness in only one ear can occur suddenly, for example, the person goes to bed with normal hearing and wakes up the following morning with complete hearing loss in one ear.
There is no single cause of this pathology: some children are born with unilateral deafness, while in others it arises from complications that occur during pregnancy.
In adolescents, this disease is provoked by:
- Meningitis
- High fever
- Measles
- Mumps
In some cases, it occurs as a hereditary disease, while in adulthood the following causes are mainly:
- Serious infections
- Earwax plug in the ear canal
- Trauma
Hearing loss in children
Childhood hearing loss can be of the following types:
- Neurosensory: develops due to congenital factors such as toxoplasmosis, rubella, CMV, herpes or syphilis, genetic factors, certain clinical pictures, low birth weight, noise or ototoxic drugs.
- Conductive hearing impairment: caused by malformation of the outer ear, eardrum, ossicles or middle ear.
- Acquired hearing loss: most commonly caused by an overproduction of earwax in the ear canal, a foreign body in the ear, a tumor, problems with the Eustachian tube, acute and/or chronic ear infections and eardrum perforation.
Symptoms of hearing loss
The first signals in case of loss of hearing are:
- Difficulty understanding what other people are saying.
- The patient often asks to repeat what has been said.
- Listening to music or watching TV at high volume.
- Difficulty hearing the telephone or house bell.
- The patient often feels tired and stressed as he has to concentrate excessively to listen to other people.
Therapy of hearing loss
First, an appointment must be made to the otolaryngologist, who will perform some examinations (for example, an audiometric examination) to determine the cause and determine appropriate therapy.
Treatment depends on the type of hearing loss the patient has:
- Surgery improves hearing loss caused by otosclerosis or excessive scarring.
- Infections are often treated with antibiotics and, in more serious cases, surgically treated.
- Meniere’s disease is treated with a special diet and medication.
Hearing loss can also be caused by the use of certain medications. In this case, the patient is recommended to consult the family doctor to undergo a different type of drug therapy.
In any case, timely treatment for sudden hearing loss significantly increases the patient’s chances of regaining hearing.
With sudden hearing loss due to damage to the auditory nerves, good results can be achieved in a hyperbaric chamber if there are no contraindications for the patient. As a result, the concentration of oxygen in the blood is increased.
Patients with permanent hearing loss need to learn how to manage residual hearing efficiently: most of these patients benefit from one hearing aid, even if only one person in five uses it.
Hearing aids are small instruments that are usually worn in or behind the ear and amplify the sounds loud and clear for the patient. Often the sound through the hearing aids is different, so it is important to talk to the doctor about it in order to achieve realistic results when restoring hearing loss.
There are some novel technologies that make it possible to improve sound perception in patients with hearing loss: new hearing aids are tailored to what the patient wants to hear and attenuate other, superfluous sounds. There are also devices through which the patient listens to television or radio without increasing the volume. Also, some devices with a sound amplification have been specially developed for the fixed phone and the mobile phone.
Finally, there are cochlear implants, which are mainly used in young children, but are also becoming increasingly popular among adults with profound hearing loss.
