According to World Health Organization data, there are 600 million hearing impaired individuals in the world. In Turkey, 2 thousand to 1 million 300 thousand babies born each year are born with hearing loss. In order to prevent hearing loss in newborn babies and not to adversely affect the physical and mental development process of the baby, the importance of 'Newborn Hearing Test' after birth is of great importance.
The Department of Health recommends that all newborn babies receive hearing screening tests and how they can respond to your child's hearing loss in a timely manner. Hisar Intercontinental Hospital Otorhinolaryngology and Head and Neck Surgery Specialist Op. Dr. From Tayfun Demirel We learned.
What is the importance of early diagnosis and intervention to prevent hearing loss in newborn infants?
Babies complete their physical and mental development with auditory, visual sensory stimuli from their environment. The absence or absence of these stimuli affects the language development of children. It may also lead to academic failure, social, emotional and psychological disorders. The sooner the child begins to fully perceive the audible stimuli, the more healthy and proper the language and social development will be. For this reason, every baby born is subjected to hearing screening tests without discharge. These tests are very important for early intervention and rehabilitation of babies with hearing impairments.
What is the hearing process in the newborn?
The reactions of the newborn to the sound is a reflex event and is proportional to the intensity of the sound. It gives roughly information about whether the sound has been received. However, it does not determine the degree of hearing loss. During the development process from birth to the age of 2, the baby who is exposed to high sound intensity, which we call startle reflex, should act as a jump. The newborn with severe or total hearing loss does not develop this reflex against sound.
• From the 3rd month onwards, human voice becomes the most important stimulus.
• Between 6-9 months, the baby turns his / her head in the direction of sound.
• After 10 months, the baby starts to react when the name is mentioned.
• Responds to some verbal commands after 12 months.
• After 18-24 months, as the vocabulary develops, the hearing system is examined orally.
When and how to test hearing for newborns?
Special test techniques are required to obtain valid and reliable results in hearing testing for newborns. If there is a failure in the Otoacoustic Emission Test (OAE) after delivery, it is repeated after 2 weeks. If the failure recurs, the Auditory Brainstem Response Test (ABR) is used to determine if there is hearing loss.
In the Otoacoustic Emission Test, called the screening test, the baby's ears are given sounds of a certain severity, and the response of the inner ear cells is measured to determine whether or not they hear. This test doesn't hurt or disturb the baby. The test is performed in a very short and quiet environment, usually while the baby is sleeping; because the baby's crying or making sounds during the test makes it difficult to control the hearing.
No anesthetics or sedatives are used during the test. After a soft-tipped device is inserted into the outer part of the baby's ear, 'click' sounds are emitted from the ear. When the ear hears this sound, the inner part of the ear echoes and the tester can, through the computer, examine how the baby's ear responds to the sound.
It also measures the severity of hearing loss; Auditory Brainstem Response Test (ABR) is one of the most commonly used objective tests. The ABR test is a study of the measurement and evaluation of electrical waves in the brain stem of a dormant newborn with electrodes placed in the head.
It is important to note that these tests can only identify infants at risk for congenital hearing loss.
What is the critical age range in terms of the ability of children in development to speak?
What are the risky conditions for hearing loss?
In newborns, 50% of cases with hearing loss have no known risk factors. Risk factors causing hearing loss are present in 10% of live births. These;
• Toxoplasma, rubella cytomegalovirus or herpes virus infection, which can cause hearing loss,
• To stay in intensive care for more than three days after birth,
• Use ototoxic (a chemical containing a harmful ear effect on the side effects),
• Using ototoxic drugs during pregnancy,
• Children with bacterial meningitis,
• Family history of deafness,
• The baby is born under a weight of 1 kilo 500 grams,
• Oxygen-free for a long time during labor,
• Need artificial respiration,
• Face-ear anomaly in the baby,
• In cases where there is a risk of hearing loss, such as jaundice, the test should be performed.