Hearing

Hearing is the process by which sounds are analyzed and processed in the auditory center of the brain via the external ear, middle ear, inner ear, and auditory nerve. As a result of this processing, sounds acquire emotion and meaning. These meanings shape our lives. Some of us love the sound of the waves in the sea, others love the sound of rain. Some find solace in listening to a soprano, while others enjoy the sounds of birds and the rustling of trees…

The sense of hearing shapes our personality and guides our decisions. Moreover, it enables us to reach our individual potential. We hear, we learn, and we decide…

Doctor Audiologist Emel Uğur

Dr. Audiologist Emel Uğur was born in 1982 in Çanakkale. During her 15-year tenure at Istanbul Training and Research Hospital, she primarily worked on Pediatric Audiology (Hearing Loss in Infants and Children), Otological Diseases (Ear Diseases and Hearing Health), and Vestibular System Disorders (Vertigo and Imbalance). In 2015, she joined the Acıbadem Healthcare Group.

About Me

How is Hearing Loss Defined and Managed?

Hearing loss is a reduction in auditory perception that occurs when one or more of the anatomical regions responsible for hearing fail to function properly due to various reasons. The symptoms and complaints arising from hearing loss vary depending on its type, degree, and configuration.

The loudness of sounds decreases logarithmically according to the degree of hearing loss. For example, in mild hearing loss, most speech sounds can be heard normally, but there is difficulty in hearing low-intensity sounds such as whispers or the rustling of leaves. In moderate hearing loss, the individual struggles to hear most speech sounds, while in severe to profound hearing loss, only very loud sounds can be heard.

Moreover, hearing loss is not such a simple concept. The human ear has a frequency range of 16 Hz to 20,000 Hz. Which frequency range is affected is a very determining factor when discussing hearing loss. For instance, an individual who hears low frequencies well but has moderate hearing loss in high frequencies might not notice the loss because their ability to hear low frequencies allows them to determine the direction of a sound, locate its source, and recognize its owner. However, due to the existing loss in high frequencies, they may not be able to distinguish spoken words. This leads to the situation of “I hear, but I do not understand.” Therefore, the impact of hearing loss on each individual and its effect on quality of life vary according to its degree, type, and configuration. It should be evaluated subjectively.

Most audiological evaluations are performed in sound-isolated rooms using special headphones in silence. The data obtained from these evaluations are collected under optimal conditions when the individual is fully focused on the hearing test. When these data are charted on an audiogram, even a mild degree of hearing loss indicates that the individual must exert significant attentional effort to understand speech in noisy environments.

The diagnosis and treatment of hearing loss is a complex process that requires the involvement of healthcare professionals from different disciplines, depending on the age group. The primary team for hearing issues includes audiology specialists and ENT doctors.

When it comes to hearing loss in children:

• Clinical Audiologists
• Educational Audiologists
• ENT (Otorhinolaryngology) Physicians
• Special Education Teachers
• Pediatric Neurologists
• Child Psychiatrists
• Pediatric Geneticists
• Pediatric Ophthalmologists, etc.

Managing hearing loss is made possible through the coordinated efforts of these specialists, and this process directly impacts an individual’s quality of life.

In elderly individuals with hearing loss, in addition to ENT and audiology specialists, neurologists are involved in the process to preserve cognitive functions.

What are the Causes of Hearing Loss?

Hearing loss can be examined in several main categories:

• Conductive hearing loss
• Sensorineural hearing loss
• Mixed hearing loss
• Central auditory processing disorders

Conductive Hearing Losses

Conductive hearing loss is a condition in which sound is not transmitted properly to the inner ear due to various problems originating in the external or middle ear. As a result, the perception of loudness is impaired, and individuals experience a sense of blockage and reduced hearing. Conductive hearing losses are most often correctable with medical or surgical treatments. In cases where they cannot be corrected, appropriate amplification methods are employed.

The conditions that cause this type of hearing loss include:

• Structural abnormalities of the auricle or external auditory canal,
• Earwax (cerumen) blockage,
• Presence of foreign bodies in the external auditory canal,
• External ear infections,
• Pathologies related to the tympanic membrane (e.g., retraction, perforation, thickening, etc.),
• Fluid accumulation in the middle ear, middle ear infections,
• Problems arising from the ossicles (calcifications or ossicular chain discontinuities),
• Eustachian tube dysfunctions,
• Cholesteatoma and other benign/malignant tumors.

Sensorineural Hearing Losses

Sensorineural hearing loss is caused by problems in the cochlea (inner ear) or the auditory nerve. These losses are permanent. There is usually no medical (pharmaceutical) treatment available. The hearing loss is monitored according to its degree and configuration, or amplification methods such as hearing aids are used.

These losses are generally associated with:

• Dysfunction of hair cells,
• Damage to the eighth cranial nerve.

Mixed Hearing Losses

Mixed hearing loss refers to a combination of conductive and sensorineural hearing losses. In this case, there are pathologies in both the mechanism of sound transmission to the inner ear and in the inner ear (cochlea) or auditory nerve. Medical (pharmaceutical) treatment or surgery can be used for the conductive component of mixed hearing loss. However, these interventions do not treat the sensorineural component. If, after treating the conductive component, a level of sensorineural hearing loss remains that affects daily life, the use of a hearing aid may be necessary. It requires close monitoring.

Central Hearing Losses

Central hearing losses are problems that occur in the processing of sound. The auditory nerve fails to correctly transmit information to the brain, and as a result, the auditory center in the brain cannot properly receive and process the signals. This can occur due to congenital lack of synchronization of the auditory nerve, illnesses, traumas, tumors, or other causes. In cases of central hearing loss, tests such as pure-tone audiometry may not aid in the diagnosis. Individuals with central hearing loss may show normal hearing findings on these tests. Therefore, a detailed audiological evaluation including advanced diagnostic procedures is required.

What are the Causes of Hearing Loss?

There is no single cause of hearing loss. It can be attributed to genetic factors, infections, lifestyle choices, exposure to pharmacological or chemical agents, occupational noise exposure, age-related changes, and more.

The worldwide incidence of congenital hearing loss is approximately 0.5% to 1%. Genetic factors are quite common in the pediatric population. Genetic hearing loss can manifest as either syndromic or non-syndromic. Given the number of syndromes characterized by hearing loss, children with hearing loss should definitely be evaluated by genetic specialists. However, not every case of hearing loss is associated with a syndrome. Isolated hearing loss is much more common than syndromic hearing losses. These cases are generally associated with autosomal variations and unknown genetic heterogeneity.

Various factors occurring before birth, during birth, and in the postnatal period can also lead to hearing loss. These factors include:

• Exposure to bacterial or viral infections,
• Exposure to various teratogens,
• Premature birth,
• Low APGAR score,
• Neonatal jaundice and sepsis.

Postnatal infections such as meningococcal infections and mumps can lead to hearing loss. Additionally, head injuries or chronic recurrent otitis media may also cause hearing problems.

In school-aged children, the frequency of hearing loss may increase because this age group is at risk of exposure to various pathogens. In this age range, the most common causes of hearing loss are middle ear infections and head traumas.

Young people are at risk of acoustic trauma due to habits of listening at high volumes, while adults are exposed to workplace noise. Over time, ototoxic exposures and age-related changes compound these effects.

Age-related hearing loss gradually emerges later in life and is generally associated with age-related degeneration in the cochlea, particularly in the hair cells.

Otosclerosis (calcification) and ossicular chain disorders, as well as conditions like cholesteatoma, cause conductive hearing loss, which can be treated surgically.

Another important issue is sudden sensorineural hearing loss. While noise exposure is a common cause, these sudden losses in hearing sensitivity are often due to viral infections or idiopathic reasons. Tinnitus (ringing) typically accompanies this type of hearing loss. Although not present in every case, dizziness and balance disorders may also occur. Intervention within the first 72 hours is critical for treatment.

In adults, hearing loss becomes more common. Aging, prolonged noise exposure, and these interactions are among the main factors triggering hearing loss. Additionally, lifestyle factors such as hypertension, high blood sugar, and smoking can increase the risk of hearing loss.

In individuals over 70, hearing loss has become an issue for nearly two-thirds of this age group. Given the aging global population and the impact of hearing loss on quality of life, age-related hearing loss is a significant public health problem.

What are the Symptoms and Diagnostic Methods for Hearing Loss?

The symptoms of hearing loss differ between children and adults. In children, hearing loss is usually detected through careful observation of symptoms. Early signs include:

• Lack of response to sounds,
• Exhibiting behavioral problems,
• Speech difficulties and delays in language development,
• Poor academic performance,
• Mispronunciation of words.

In adults, the symptoms of hearing loss manifest more directly. These symptoms include:

• Tinnitus (ringing in the ears),
• Difficulty hearing sounds,
• Difficulty understanding speech,
• A tendency to speak louder.

Family and medical history are of great importance in diagnosing hearing loss. In children, family history provides critical details about the prenatal and postnatal periods, while in adults, past medical and family histories along with exposure to occupational noise are examined.

Physical Examination

Physical examination is the first step in confirming hearing loss. ENT doctors perform an otoscopic examination to determine whether there is any pathology or abnormality in the auricle, external auditory canal, or tympanic membrane that might interfere with audiological testing. Specific conditions to look for during the initial examination include:

• Presence of foreign bodies,
• Accumulation of earwax,
• Ear infections,
• Tympanic membrane damage,
• Fluid accumulation in the middle ear.

Doctors also take care to identify dysmorphic features and physical anomalies. These typically include:

• Facial asymmetry,
• Ear anomalies,
• Neck and skin abnormalities,
• Dysfunctions of other organs.

Audiological Evaluation

The hearing evaluation process requires specialized methods for each age group from newborns to adults. The American Academy of Pediatrics and the Joint Committee on Infant Hearing recommend that newborns undergo a hearing test at birth or by one month of age at the latest. This early diagnosis is vital for detecting potential hearing issues.

• Brainstem Auditory Evoked Response (ABR/BERA) Test: This method is commonly preferred for newborns and infants. It is an objective measurement that evaluates the function of the auditory nerve up to the brainstem. Although the test itself is objective, the interpretation of the results is subjective. It must be administered and evaluated by experienced audiologists.
• Otoacoustic Emission Test: This method is also frequently used for newborns and infants. It provides information about inner ear functions and is one of the complementary tests to the ABR test.
• Immittance Measurements: This combined method evaluates middle ear and acoustic reflex responses. It is brief and non-invasive.
• Pediatric Audiometric Evaluations: The testing technique is determined by factors such as the child’s age, cognitive development, and language development. It is a modified version of pure-tone audiometry used for adults. Various techniques such as behavioral observation, visual reinforcement, and play audiometry may be employed. The choice of technique depends on the clinician’s experience, approach, and the child’s cooperation. In pediatric groups, applying all tests together is the most accurate approach.

The fundamental tests used for adults and older children are immittance measurements and audiometric evaluations. When used together, these tests provide detailed information about hearing capacity and the source of the problem.

How is Hearing Loss Treated and Managed?

Most conductive and mixed hearing losses have a conductive component that can be treated medically or surgically. The treatment methods and protocols are planned and implemented by ENT doctors. In special cases such as congenital ear anomalies, hearing implants or devices may be required.

Sensorineural hearing losses are permanent and can be progressive. Hearing aids are the first option for compensation. In advanced or profound sensorineural losses where hearing aids are insufficient, implantation surgery may be planned.

What are the Degrees of Hearing Loss?

The grading of hearing loss is a method used to determine the extent of a person’s reduction in hearing capacity. The American National Standards Institute classifies hearing loss into various levels. The grading scales used for children and adults differ.

This classification is a critical reference point when determining the degree of hearing loss. The degree of hearing loss plays an important role in developing personalized treatment and rehabilitation plans.

What are the Possible Effects of Hearing Loss?

Hearing loss can lead to serious complications, especially in children and the elderly. In children, hearing difficulties often create obstacles in education and social interactions. Children with hearing loss may experience delays in speech development. These delays directly impact their academic performance, and the challenges faced during education can lead to a lack of self-confidence and problems in forming friendships.

• Speech delays
• Decline in academic achievement
• Social isolation

In adults, hearing loss can lead to reduced social interactions and consequently, isolation. This sense of isolation may increase the risk of depression over time. This often results in adults withdrawing from their social circles.

• Isolation from social surroundings
• Increased risk of depression

Hearing loss can negatively affect various aspects of life across all age groups and reduce overall quality of life.

What Precautions Should Be Taken to Protect Hearing Health and What Are the Patient Recommendations?

Managing hearing loss requires tailored approaches for individuals of all ages, from children to the elderly. Early diagnosis and intervention in children ensure that their language and social development are built on a solid foundation. Therefore, educating parents about hearing loss is vital to support their children’s development. Parents are informed about how to monitor their children’s hearing and when to seek professional help.

In adults, especially the elderly, hearing loss can lead to social isolation and communication difficulties. For these age groups, the proper use and regular maintenance of hearing aids is essential. Hearing aids should be adjusted to meet the user’s needs and maintained under proper hygienic conditions.

The following measures contribute to the protection and improvement of hearing health:

• Hearing checks: These should be conducted at regular intervals.
• Maintenance of hearing aids: Regular cleaning and technical inspections of the devices are necessary.