Newborn Hearing Screening

Definition/Introduction

Hearing impairment can cause a massive impact on child development, either on its language or speech development, poor academic performance, personal-social maladjustments, and emotional disturbances.[1] Prompt detection and appropriate intervention within the first six months of age has been demonstrated to decrease its adverse complications and improve language acquisition. Hence, universal newborn hearing screening has been extensively and strongly promoted and advocated as an early detection strategy for hearing loss in children.

Hearing tests, as a part of the non-biochemical newborn screening, can identify congenital hearing loss, although infants or children can acquire progressive hearing loss or deafness after birth for various reasons. Based on the etiology, hearing loss divides into sensorineural, conductive, or mixed type. Sensorineural hearing loss is the most common form of hearing loss in the neonates, with 50% of children have the genetic cause. Meanwhile, acquired hearing loss is commonly the result of infectious diseases, especially meningitis, the trauma of the nervous system, the damaging noise levels, and ototoxic drugs. The remaining causes and risk factors of hearing loss in neonates are congenital infections and hyperbilirubinemia.[2]

Some risk factors for newborn hearing loss are the history of using mechanical ventilation for five days, ototoxic medications, premature birth, low birth weight, admission to neonatal intensive care unit for more than seven days, and low APGAR score.[3] Unfortunately, more than 50% of babies with hearing loss do not have the risk factors mentioned above. Therefore, neonatal hearing screening is recommended for all newborns to dampen the misdiagnoses. 

Two recommended hearing screening techniques are the otoacoustic emissions (OAE) test, and the auditory brainstem evoked responses (ABRs) test. The OAE test is the most commonly performed test in newborn screening because of its easy, safe, and quick procedure. It is also inexpensive, easy to interpret, and provides a sensitive indication of the presence of hearing loss. It also does not require highly specialized manpower. It is particularly easy to carry out in this age group as their level of restlessness is lower than the older infants, and thereby precludes the need for sedation. If the result leads to a positive hearing loss or the test's result does not pass; thus, the newborn has to do the ABR test before three months of age. The ABR test is an auditory evoked electrophysiologic response that highly correlates with hearing and has been used successfully and cost-effectively to screen newborns and to identify further the degree and type of hearing loss. 

Issues of Concern