Hearing loss is a complex diagnostic and therapeutic problem.

Tanks to hearing screening programs, the problem can be diagnosed at an early stage and it can be treated immediately.

Some types of hearing loss in a child are reversible – when the cause is diagnosed, it can be successfully treated.

Hearing loss can be of the following types:

• conductive – caused by changes in the external ear (for example, narrowing of the ear canal, ear wax, foreign body, ear canal inflammation, congenital defects of the external ear – microtia, atresia of the external auditory canal) or in the middle ear (for example, perforation of the tympanic membrane, otitis media – acute or chronic (serous, adhesive, suppurative, with cholesteotoma), or congenital defects of the middle ear).
• sensorineural – resulting from the inner ear pathology, i.e. the cochlea and/or the auditory nerve (genetically caused hearing loss, birth defects, infections during fetal development (cytomegaly, rubella, herpes, toxoplasmosis, syphilis) or later (mumps); the effect of ototoxic drugs (aminoglycoside antibiotics, cytostatics);
• mixed – combining signs of conductive and sensorineural hearing loss.

The most common symptoms of the hearing loss in children 

Hearing loss and otitis media are common causes patients come to the doctor with.

Symptoms that should worry parents, depending on the age of the child:

• no reaction to sounds
• lack or delay of speech
• speech defects
• replacement of word parts
• incorrect repetition of what was said
• very loud sound when watching TV
• learning difficulties

Child’s hearing assessment

Hearing can be assessed at birth by performing special screening tests.

In Poland the acoustic emission method is used for this purpose. This test is performed in the neonatal wards in all newborns.

If the results of a hearing screening test deviate from the norm, the patient should be referred to a specialized center for advanced diagnostics and treatment of hearing loss. Hearing diagnostics in newborns and small children is based on objective and subjective (behavioral) methods.

It is not correct to draw conclusions about patient’s hearing only on the basis of one type of examination. The principle of cross-checking, that is, checking the reliability of the result obtained by one method using another method, is mandatory.

The main objective methods for hearing testing:

• impedance audiometry is mainly used to assess the condition of the middle ear and its diseases, but with the help of this test we can also see the function of the inner ear and other parts of the auditory pathway;
• otoacoustic emission (OAE) is used to determine the function of the inner ear (cochlea).

Both tests can be performed even in small children. They are short, non-invasive and painless.

If the result of the screening test (OAE) deviates from the norm, and especially when the control examination (OAE and impedance audiometry) is also incorrect, it is necessary to perform the auditory brainstem response test (ABR).

The ABR test gives information about the function of the auditory pathway to the level of the brain stem, and also allows to determine the hearing thresholds. This method is an objective examination and can be carried out in small children. In older children it is possible to perform subjective (with the participation of the child) tests. They give us information on hearing level, provided that they are correctly performed and they are repeatable.

The main subjective examination is pure tone audiometry.

In children up to 3 years – it is behavioral audiometry, around 3-4 years – play audiometry, which allows to make a logical conclusion regarding the hearing threshold of a child. In children aged about 6-7, as a rule, pure tone audiometry tests can be performed with greater result reliability.

Based on the results of tests carried out according to the principle of cross-checking, it is usually possible to accurately assess the level and type of hearing loss and determine appropriate treatment (conservative, surgical, or hearing aids fitting if it is not possible to eliminate the cause of hearing loss).

Causes of hearing loss in children:

One of the most common causes of hearing loss in children is chronic serous otitis media, usually due to hypertrophy of adenoids and palatine tonsils. This condition is reversible and after treatment hearing returns to normal. initially, conservative treatment is carried out (appropriate pharmacotherapy, including allergy treatment, climatic treatment, etc.). If there is no effect, surgical treatment (adenotomy/adenotonsillotomy, ear tubes) is applied.

The cause of hearing loss may also be chronic otitis media of various etiologies, combined most often with the presence of cholesteatoma. It is a serious disease, often requiring repeated surgical intervention.

Congenital malformations of the external ear with atresia of the auditory canal can lead to hearing loss, but these defects are usually diagnosed in the early stages of a child’s development.

Congenital malformations of the middle ear are deformation or absence of auditory ossicles. These defects cause significant hearing loss in the ear in which they occur. If hearing loss is bilateral, then the lack of urgent treatment or the use of hearing aids can delay the development of child’s speech.

One in 1000 children is born with a significant degree of hearing loss or deafness, and in the entire pediatric population, almost 4 % of children suffer from hearing loss.

In about half of this group, the cause of hearing loss is determined genetically. Among other factors, there are congenital viral infections (rubella, cytomegaly, herpes), protozoan (toxoplasmosis), or bacterial (syphilis), but also medications taken by a woman during pregnancy, alcohol or maternal illness (diabetes and others).

Perinatal problems (prematurity, low birth weight, perinatal hypoxia, hyperbilirubinemia) are also risk factors of hearing loss. The need for a long stay in intensive care units due to serious condition of the child, prolonged artificial ventilation of the lungs, the use of ototoxic drugs (aminoglycoside antibiotics) and serious conditions such as meningitis and sepsis are also risk factors of deafness.

Treatment:

A significant part of conductive hearing loss (i.e., at the level of the outer and middle ear) can be treated surgically.

Adenotomy (removal of the pharyngeal tonsil) and ear tube surgery are some of the most frequently performed operations in children with the diagnosis of serous otitis media and hypertrophy of the pharyngeal tonsil (adenoids). Removing thick exudate from the tympanic cavity during the surgery and improving the function of the Eustachian tube after adenotomy eliminate hearing loss.

A more complex pathology (including one that may be a complication of untreated or improperly treated serous otitis media), in which the destruction of the eardrum and/or auditory ossicles occur, can also cause conductive hearing loss. In these cases surgery is more complicated and may require, for example, the eardrum repair and ossicular chain reconstruction.

Hearing aids are used to amplify sounds that reach the ear structures. Indications for the use of a hearing aid in a child are determined by a doctor based on the results of the aforementioned hearing diagnostic tests, performed on the basis of a cross-check, confirming the hearing loss. During the selection of hearing aids the child collaborates with a hearing care professional. Most often hearing aids are used for sensorineural hearing loss, seldom for conductive of unclear etiology.

Cochlear implantation is applied when a child is diagnosed with profound hearing loss, complete or partial (i.e., high frequency) deafness.

It is generally believed that hearing loss in elderly people should be treated with hearing aids. There are other methods for hearing improvement, including surgical ones. A contradiction to surgical treatment is not age, but the general state of health of the patient.

Causes of hearing loss:

The number of patients with hearing loss is increasing due to an aging population and an increase in human life expectancy in the societies of developed countries. Age-related hearing loss occurs in most people over 75 years old, at a slightly younger age this percentage is also high.

Age-related hearing loss is a loss of hearing function connected with the aging process of the body.

The degree of age-related hearing loss depends on genetic factors, because each patient has an individual tendency to hearing loss.

Harmful factors, such as noise or ototoxic drugs, can damage hearing at any age.

Factors that can accelerate hearing loss: systemic diseases, such as vascular diseases, hypertension, atherosclerosis and others.

Age-related deafness is most often a combined result of genetic factors and adverse environmental factors, influencing the patient throughout their life.

Signs of hearing loss:

Age-related hearing loss does not occur as a sudden decrease in hearing; it develops slowly over many years. Symptoms of typical age-related hearing loss are: progressive bilateral hearing loss, tinnitus, especially in silence/at night, impaired speech discrimination, especially in noise.

Examinations:

When contacting an audiologist, a patient should undergo ear examination, including microscopic examination (it allows to accurately assess ear condition, including changes in the external auditory canal, and the eardrum condition), and audiological examinations should also be performed.

Diagnostics is based on subjective hearing tests:

• pure tone audiometry is the main hearing test that should be performed;
• speech audiometry is an additional test that is necessary to perform in patients with hearing aids to assess the benefits of hearing aids.

Objective hearing tests (not requiring patient collaboration):

• impedance audiometry is mainly used to assess the condition of the middle ear and its diseases, but with the help of this test we can also see the function of the inner ear and other parts of the auditory pathway;
• otoacoustic emission (OAE) is used to determine the function of the inner ear (cochlea).
• the auditory brainstem response test (ABR), it gives information about the function of the auditory pathway to the level of the brain stem. The assessment of the hearing thresholds by this method in adults is usually performed in patients who are not collaborating, for example, patients with mental retardation, unconsciousness, autism or for the purpose of a forensic or professional examination. However, the ABR test is extremely valuable and useful in the diagnostics of so-called extracochlear hearing impairment, which can cause an acoustic neuroma/cerebellopontine angle tumor.

Treatment:

If an elderly person has hearing loss that can be treated surgically, this type of treatment should be considered. Damage to the tympanic membrane or ossicles can be successfully treated surgically, if there are no other  medical contradictions. If patient’s health condition does not allow to be operated under general anesthesia, appropriate hearing aids should be offered to the patient.

Another method of surgical treatment is the use of auditory implants depending on the type and depth of hearing loss. Age is also not a contradiction to such kind of treatment. Auditory implantation is performed in the same way as other hearing improvement surgeries under general anesthesia.

Hearing aids for the elderly:

If hearing loss is not treated surgically and despite the technical capabilities, the patient’s condition does not allow treatment under general anesthesia, a hearing aid is offered to the patient. Such a device should be selected according to the type of hearing loss of the patient. Therefore, it is very important to perform pure tone audiometry correctly. Incorrectly performed audiometric tests will cause improper selection and programming of the hearing aid, which will lead to unsatisfactory effects (there is no improvement of speech understanding), or even to adverse effects (for example, headaches, in extreme cases, acoustic trauma).

The policy of treatment depends on the type of hearing loss. Hearing aids and auditory implants are used for sensorineural hearing loss, while surgery is recommended for mixed or conductive hearing loss.

The type of hearing loss is determined by diagnosis in an audiology clinic. Various factors are taken into account in qualifying for surgery, including the age and general condition of the patient.Hearing improvement surgery is not a lifesaving procedure. That is why we do refuse this type of treatment when the patient’s risk of general anesthesia outweighs the potential benefit.  Conductive hearing loss Conductive hearing loss often occurs with exudative otitis media, with damage of the tympanic membrane and / or auditory ossicles, at the initial or intermediate stage of otosclerosis.This type of hearing loss, especially if it bothers the patient, should be treated with surgery. It should be underlined that the prognosis of improvement of hearing after surgery is usually good. It mostly refers to otosclerosis, where more than 95% of the patients undergoing surgery can achieve a permanent hearing improvement and there is no further need to wear hearing aids. Conductive hearing loss tends to develop, and surgery is needed not only to improve hearing but also to prevent the development of disease. In otosclerosis, hearing improvement is usually achieved after the first operation. Conductive hearing loss is also noticed in congenital ear abnormalities in the form of the absence of external auditory canal often combined with defects of the auricle. In this case, a very good solution is to use auditory implants, the aim of which is to stimulate the middle or inner ear passing the auditory canal.

Mixed hearing loss Mixed hearing loss occurs due to simultaneous damage of the both middle and inner ear. It can occur as a result of rapidly and aggressively developing otosclerosis, which destroys not only the middle ear, but also the cochlea. This type of hearing loss is also common in long-term chronic otitis media, often with cholesteatoma, and should be treated surgically unless otherwise recommended. Auditory implants can be used in the situations where it is not possible to improve hearing through classical otosurgery, and they are often the only good choice. Sensorineural hearing loss Changes that cause hearing impairment can be localized in the cochlea (inner ear) or, less often, have a retrocochlear localization (changes affect the peripheral part of the auditory tract – the cochlear nerve). This type of hearing loss can be congenital due to inner ear defects, viral infection, or cochlear hypoxia. Sometimes when the patient loses hearing within one day,so-called sudden deafness occurs.
Hearing improvement surgeries similar to those performed for conductive or mixed hearing loss are not applicable here and do not pay off as they do not improve hearing.   Hearing loss treatment with implantation is used in cases such as:– profound hearing loss and lack of benefit from hearing aids;- recurrent, persistent inflammation of the outer ear, which does not allow the use of hearing aids (due to the pain while wearing the device) and chronic inflammation of the middle ear, with the inability to improve hearing with surgical methods;
– anatomical abnormalities that prevent wearing of hearing aids (for example, a narrow external ear canal, post-inflammatory or post-traumatic changes). 

 Sensorineural hearing loss – partial deafnessPartial deafness is a hearing loss that is usually caused by an internal ear damage and can also be congenital. Most often, we do not know the exact cause of this type of hearing loss. If the child has this kind of disorder from birth, they are often not detected at all, or they are detected late, by accident, for example during a hearing screening. In the beginning, hearing is usually prosthetized with hearing aids, which amplify sounds reaching the cochlea. In this type of hearing loss, cochlear implant treatment can be used if the hearing loss is so great that hearing aids are ineffective and the benefit is not sufficient for the patient.

Sudden sensorineural deafness is a condition of sudden hearing loss within a short period of time (a few hours). This condition requires urgent diagnosis and immediate treatment, which increases the chances of improving hearing.

Causes for sudden hearing loss and deafness:

Sudden bilateral deafness is rare and usually associated with factors that can be identified, such as head trauma with temporal bone fractures, exposure to rapid pressure changes (barotrauma), severe viral and bacterial infections including meningitis, toxic, medical and other injuries.

Single-sided, sudden hearing loss is a situation that is common in relatively healthy people; at an early stage, there can be tinnitus, sometimes also dizziness. The reason for this is not fully known. However, there are links to some factors that can affect hearing. The most common are vascular, inflammatory or traumatic causes (including acoustic trauma).

It is believed that sudden single- sided deafness can be also caused by stress, that narrows down cochlear vessels, causing complete ischemia of the hearing organ receptor, the inner ear, in a manner similar to that of a heart attack. Thromboembolic complications are also often the cause of vascular etiology in sudden deafness.

Patients with blood pressure disorders, both low-pressure and hypertensive, have a greater risk of this type of sudden disorder. In addition, some systemic diseases are predisposing to sudden hearing impairments, including lipid metabolism disorders (hypercholesterolemia) and diabetes.

Another factor – inflammatory – can be a severe viral infection, even subclinical (asymptomatic). Viruses and the presence of inflammatory processes in the body cause toxic damage to delicate and sensitive cells in the cochlea.

We must not to forget that a one-sided hearing loss, including deafness, can be caused by a tumour of the auditory nerve. Additional examinations (MRI) should be performed to eliminate it.

Characteristic symptoms:

Typical onset of a sudden one-sided hearing loss: tinnitus and hearing loss for no apparent reason in the morning, after waking up. There may also be a feeling of overflow in the ear and dizziness (but less often).

Hearing test:

In the case of a noticeable hearing loss, especially with accompanying symptoms such as noise or dizziness, you should see a doctor who will diagnose the cause and determine the most appropriate treatment procedure.

The following hearing tests should be performed:

– Weber and Rinne tests

– pure one audiometry

– impedance audiometry (tympanometry and stapedial reflexes)

– otoacoustic emission

– ABR test

Not frequently, but due to the nature of the condition, which requires early diagnosis, sudden deafness is caused by a tumour in the auditory nerve, which causes symptoms such as hearing loss and tinnitus as it grows.

Depending on the degree and type of hearing loss in a one-sided or asymmetrical hearing loss, additional tests should always be carried out in order to exclude the occurrence of a tumour of the auditory nerve/cosmeletal angle (electrophysiological hearing tests – ABR and MRI of the temporal bones with contrast (in the case of patients with contraindications for MRI test – CT of the temporal bone pyramids).

Methods of treatment of a sudden hearing impairment:

There are different ways to treat the sudden hearing loss depending on the severity. It is important to determine, as far as possible, the causes of a sudden hearing loss. Your doctor may prescribe medication at home or refer the patient to a hospital for pharmacological treatment in case of a sudden hearing loss. The increasingly available hyperbaric oxygenation treatment should not be underestimated.