OAE: Otoacoustic Emissions Test (OAEs)
OAE is a hearing test used for newborn screening test which should be done after the child’s birth and before leaving the hospital.
If your child fails in OAE screening hearing test, it is recommended to have a hearing screening within 3 weeks of life, because failing in first screening does not mean that your child has a hearing loss, he/ she could fail in first screening because of fluid and debris in the ear. In OAEs a miniature ear earphone and microphone are placed in the ear, sounds are played and a response is measured. If the baby hears normally, an echo is reflected back into the ear canal and is measured by the microphone. Whenever a baby has a hearing loss, no echo or a reduced echo can be measured on the OAE test.
Automated auditory brainstem response (ABR) audiometry is the best test available for newborns and infants up to 6 months of the age that can provide information about the softest level of sound that ear can hear. Sounds are played in the baby’s ear and bandaid like electrodes are placed on the baby’s head to detect the responses. Sounds are presented to the ears using small earphones. The electrodes pick up responses from the hearing nerve and a computer measures the responses to identity babies who have a hearing loss.
Hearing impairment is one of the most critical sensory impairments with significant social and psychological consequences. Reported incidence of congenital hearing loss is 30 per 10,000 children. Significant hearing loss is the most common disorder, occurring in 1 to 2 newborns per 1000 in the general population, and 24% to 46% of newborns admitted to neonatal intensive care unit. Vocabulary of a 3-year-old child with hearing impairment if remediated at birth is 300-700 words; if re-mediated at 6 months is 150-300 words and if remediated at 2 years is 0-50 words, respectively; as compared to vocabulary of a 3-year-old child with typical hearing which is 500-900 words. (PAUL et al. CONSENSUS STATEMENT ON NEWBORN HEARING SCREENING)
IAP (Indian Accademy of Pediatrics) guidelines recommendations:
The first screening should be conducted before the neonate’s discharge from the hospital – if it ‘fails’, then it should be repeated after four weeks, or at first immunization visit. If it ‘fails’ again, then Auditory Brainstem Response (ABR) audiometry should be conducted. All babies admitted to intensive care unit should be screened via ABR. All babies with abnormal ABR should undergo detailed evaluation, hearing aid fitting and auditory rehabilitation, before six months of age. The goal is to screen newborn babies before one month of age, diagnose hearing loss before three months of age and start intervention before six months of age.
The goal is to screen newborn babies before 1 month of age, diagnose hearing loss before 3 months of age and start intervention before 6 months of age.