Identification, Diagnosis and Treatment of Hearing Loss

Hearing loss in babies with a significant hearing loss begins during pregnancy. During the last 12 weeks of pregnancy, the auditory system of the fetus responds to sounds and speech. The auditory system in babies born with an inability to hear sounds and speech in their environment after birth is incapable of being efficient, resulting in the formation of developmental delays.

The Significance of Early Diagnosis

Babies’ and children’s ability to hear normally strongly affects the development of their language and speech, as well as emotional, social and intellectual development. Early diagnosis of hearing loss in babies and children is expected to increase the chances of developing skills and abilities similar to children who do not have a hearing loss. If you suspect that your child’s hearing is impaired, it is important that you have the hearing checked out.

Diagnosis of Hearing Loss in Babies and Children

A diagnosis of hearing loss requires an in-depth examination that involves several tests: hearing screening test, a behavioral hearing test and an objective hearing test.

Objective Hearing Test

Hearing Screening Test

• The first hearing test that your baby will undergo on the first or second day of life, when still hospitalized, is the hearing screening test known as OAE (Oto Acoustic Emission) test. The test will be performed while the baby is calm or sleeping, during which a small earpiece will be inserted into the outer opening of the ear canal. A sound will be made in each separate ear at fixed decibel and the middle ear response will be measured. The test is designed to detect hearing loss in the early stage, and to refer these babies to a comprehensive auditory diagnosis at a hearing institute. If the test raises a suspicion of a hearing loss, the screening test will be repeated.
• If a hearing loss is suspected during the OAE test, you will be referred to a hearing screening test known as AABR – Automated Auditory Brainstem Response at a medical center. In newborns, the test will be performed while the newborn is sleeping, during which electrodes will be placed on the infant’s head, and the electrical activity in the auditory nerve tracts in the brainstem, in response to sounds made at a fixed decibel.

Diagnostic Hearing Test

If the repeat screen also reveals a hearing loss or if the babies are slightly older and are finding it difficult to cooperate in the behavioral test, you will be referred to a diagnostic hearing test – BERA or Brainstem Evoked Response Audiometry or the ABR – Auditory Brain Stem Response. The test is performed at special medical centers dedicated to hearing tests for babies and toddlers, and due to the need to diagnose the responses of the auditory nerve in the brain stem, the patient must be ‘extremely still’, in other words, small babies must undergo the test while sleeping or under sedation. While asleep, electrodes will be placed on the baby’s head and the electrical activity in the auditory nerve tracts in the brain stem in response to a series of sounds made in the ears at varying decibels will be recorded. The test begins with sounds at a high decibel, with the decibels gradually being lowered – up to the point where there is no nerve response known as the “threshold of hearing”.

Behavioral Hearing Test

If a hearing loss is diagnosed, you will be referred to a behavioral hearing test. The test is performed in a special acoustic booth for hearing tests, where you will sit with your baby, and various sounds will be heard through the speakers. Infants of only several months of age, the clinicians will form an impression from the baby’s physical responses to the sounds being made such as blinking, limb movement, opening of eyes, stopping sucking on the pacifier, turning the head in the direction of the sound, etc. They will form impressions from the age-appropriate physical responses for the baby and his or her stage of development.

Older children who display an understanding of language and are beginning to speak will be asked to point to an object whose name they heard on the earphones or speakers. In addition, based on their age and level of development, they will hear sounds and will be asked to search for the source in the space using ‘ visual feedback’, or play a game, such as stacking rings on a stand, where each time weak sounds will be planed. The aim is to diagnose the threshold of hearing for a range of sounds.

Once both tests (objective and behavioral) have been conducted, and based on the results, a threshold of hearing will be determined by the clinician or speech pathologist. You will bring the test results to the attending physician, who will refer you based on the findings to a physician or an ENT specialist, to determine whether medical or rehabilitative intervention is needed.

Signs that may indicate hearing loss

• Babies who do not wake up when loud sounds are made around them.
• Babies who are not startled by loud or sudden sounds.
• Babies who do not respond to sounds in their environment, according to their age.
• Babies who do not react to familiar sounds such as their mother’s voice and the opening of a door.
• Babies who do not turn their head or look for the source of the sound, around six months of age.
• Babies who rarely use their voice, and the range of sounds when mumbling is limited, around 9-10 months of age.
• Babies who do not try to repeat sounds that were made, around 10 months to one year old.
• Babies who do not begin to show understanding of simple questions or initial instructions such as “Say bye-bye” or Where’s the light?, around the age of one year to 15 months.
• Babies who do not utter first words around one year to 15 months of age.

If you noticed one or more of these signs, you should request a referral for a medical diagnosis to rule out, in the first stage, local blockage of the ears due to infection and disease, and later a referral to a more in-depth hearing test at a licensed hearing institute.

For more information about genetic testing and the course of pregnancy

Congenital Causes of Hearing Loss in Babies

Genetic hearing loss is the result of the inheritance of one or more defective genes from among the genes responsible for the formation and development of ears. In most children with hearing loss, the hearing problem is the only genetic problem. For the rest, the hearing problem is only one of several symptoms that belong to the genetic syndrome.

Congenital hearing loss may be attributed to the following factors:

• Mutation of genes involved in the auditory process: At least half of diagnosed cases of congenital hearing loss and congenital deafness is estimated to be genetic in origin. In other words –a defective gene passed down by one or both of the parents. There are over 130 genes involved in the auditory process and essentially a mutation in any of them potentially harms hearing. Approximately one-third of cases of deafness manifests as one of a collection of impairments typical of certain genetic syndromes, such as Usher’s Syndrome, Waardenburg Syndrome and Alport Syndrome.
• Infectious disease of the mother during pregnancy: the fetus being infected by diseases such as measles, CMV, toxoplasmosis and syphilis, particularly in the first trimester of pregnancy, may harm hearing to the level of partial or full deafness. Regular pregnancy monitoring, including blood tests to diagnose antibodies for diseases that are responsible for most intrauterine infections (this can be tested during the prenatal planning), may detect and even prevent these types of cases. For example, if a woman who is not pregnant is found to have no antibodies for measles, she can receive the vaccine before becoming pregnant.
• Combination of genetic and environmental factors: for example, hearing loss that developed in a baby due to the mother taking ototoxic medications during pregnancy (medication that can damage the inner ear); abnormal development of the auditory system during the early stages of fetal development; emergency during or immediately after birth that may cause hearing loss to the level of deafness, such as premature birth, prolonged neonatal jaundice with high bilirubin levels, prolonged artificial ventilation.

Hearing Screening for School Pupils

Hearing screening test for pupils will be performed round the time they begin school, in the first grade, and for second graders who did not take the test in the first grade. Pupils who were already diagnosed with hearing loss and use a hearing aid or implant do not need to be tested.

For more information about the hearing test in school

Audiologic Rehabilitation

Once a child is diagnosed with hearing loss, an audiologic rehabilitation process will be personalized for every individual. Rehabilitation with technological aids, such as hearing aids and implants, opens doors for children to a lengthy rehabilitation that will also include auditory learning, auditory training and speech therapy to acquire normal speech and language skills.

For more information about audiologic rehabilitation in babies and children

To apply for financial assistance for hearing aids for children under the age of 18

Coping and Receiving Assistance

A diagnosis of a disability in babies is a process that poses challenges, particularly for parents. It is only natural and legitimate that you experience such emotions as anxiety, sadness and anger. It is important that you know that these are part of the coping that generally results in acceptance. It is important that you are aware of these emotions and, if necessary, seek advice and emotional support.