What Is Neonatal Hearing Screening?
Newborn hearing screening is now the standard of treatment in hospitals nationwide. The main goal of newborn hearing screening is to identify infants who need additional testing and are likely to have hearing loss. Secondary goals include identifying neonates with medical disorders that may result in late-onset hearing loss and developing a strategy for ongoing hearing status monitoring.
The EHDI guidelines state:
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A hearing test must be completed by one month of age.
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Any hearing loss must be diagnosed by three months of age, hearing aids must be chosen and fitted no later than one month after a hearing test confirms a hearing loss.
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No later than six months of age is the cutoff for beginning early intervention (EI) services.
What Tests Are Done to Check for Hearing Loss in Newborns?
Otoacoustic emissions (OAEs) and the auditory brainstem response (ABR) are suitable physiological tests for neonatal population screening. Both are non-invasive and offered in automated forms that are simple for skilled hospital staff.
Otoacoustic Emissions: OAEs are energy detected as sound and produced by the hair cells outside the human cochlea in reaction to auditory input. The screening test was created in 1978 by David Kemp after a geophysicist in the middle of the 1940s first mentioned it. Based on the sound echoes phenomenon, ear-specific probes are inserted into the external ear canal to deliver a sound stimulus to the baby's auditory system. The probe simultaneously captures emissions from the cochlea's outer hair cells through the middle ear. About 99% of ears with normal hearing can record OAEs. When the hearing loss is 30 dB or more, the response is typically missing in the ears.
Auditory Brainstem Response: ABR activity is a direct evaluation of the neurological reaction to the sound created along the auditory system from the cochlea to the brainstem, and it corresponds with behavioral hearing tests in the mid-to high-frequency zone. Surface electrodes are placed on the infant's head to record the ABR. Click stimuli are delivered via insert- or muff-style earphones in both ears. ABR readings are sensitive to auditory neuropathy and other neural auditory abnormalities. Hearing loss caused by auditory neuropathy preserves cochlear (outer hair cell) function.
What Are the Protocols for Neonatal Hearing Screening?
Four main categories can be used to classify screening protocols:
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ABR alone.
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OAEs alone.
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OAEs with quick ABR rescreening if OAE is unsuccessful; two-tier.
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ABR and OAEs are two technologies.
Factors to Consider:
When employing an ABR-only screening strategy, take into account the following elements:
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ABR screening allows greater access to the auditory system than OAEs, making it possible to identify neurologic involvement.
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Compared to OAE screenings, the results of ABR screenings are less likely to be false positives because of ear canal debris.
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Due to the higher cost of disposables and extra staff time, ABR screening can be less economical than OAE screening.
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Because of the inclusion of electrodes, the ABR test time could be lengthier than the OAE test period.
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When utilized on infants whose undeveloped neurological systems alter the ABR waveform, ABR will produce false positive results.
When utilizing an OAE-only screening strategy, take into account the following factors:
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Disposable OAE supplies are frequently less expensive than ABR supplies.
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OAE test duration is smaller than ABR test time.
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OAEs are unable to identify neural hearing loss.
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Compared to ABR, OAEs have a greater rate of inpatient referrals.
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OAEs possess a higher rate of false positives than ABR.
When employing a two-tier screening strategy, the following elements should be taken into account:
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A two-tier procedure will result in fewer diagnostic testing referrals than an OAE-only protocol.
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Using two different disposables and two pieces of equipment is necessary, while some manufacturers only use one for both testing.
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Two procedures need to be taught to staff members.
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An infant may fail the OAE screening but clear the ABR screening because various tests identify different levels of hearing loss differently. As an outcome, some kids with slight hearing loss could go unnoticed.
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Because infants who pass an OAE screening are not recommended for an ABR, a two-tier strategy may miss auditory neuropathy.
When adopting a two-technology screening strategy, the following aspects should be considered:
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Due to the employment of OAE and ABR technologies, a two-technology protocol is more likely to detect mild and neural hearing loss.
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It is necessary to buy and maintain two pieces of equipment: a device that performs both tests and two different kinds of disposables.
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Both technologies require training for staff members.
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Due to the completion of two procedures, additional screening time is necessary.
What Approaches Are Used to Treat Hearing Impairment?
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A coordinated team of family doctors, pediatricians, audiologists, otolaryngologists, and speech pathologists/educational experts services should be used to manage children with hearing loss. Depending on the cause, hearing loss needs to be managed. The following general categories might be used to group early intervention strategies:
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Child and family support, medical or surgical management, and educational and rehabilitation techniques.
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Technology advancements over the past two decades have greatly improved medical and surgical operations to create functional access to sound. This might include hearing aids, cochlear implants, or bone-anchored hearing aids, depending on the cause and degree of hearing loss. With the help of innovative digital technology, hearing aids that provide sound amplification are now readily accessible and may be utilized by very young newborns.
Cochlear implants are electronic devices inserted through surgery in the cochlea to stimulate the auditory nerve and have been used in children for 20 years. The development of linguistic proficiency and literacy growth in deaf or hard-of-hearing children is the main emphasis of habilitation programs. This can be expressed in various ways, such as through speech, gestures, or a combination of the two. Families need a clear, unbiased explanation of the intervention options and anticipated results.
Conclusion:
No matter the form, screening programs aim to detect permanent childhood hearing loss (PCHL). However, specific techniques are more effective in detecting different types and levels of hearing loss within various groups.
A child's ability to pass a screening does not guarantee normal hearing throughout the frequency range. Newborns with mild and frequency-specific hearing deficits may pass a hearing screening since newborn hearing screening programs do not address these losses. Surveillance of hearing, speech, and language milestones throughout childhood is crucial since these losses can impede children's speech, language, and psychoeducation development.
