New born hearing screenings
- Part 2 -

Meenakshi Chanu *

Methods to identify Hearing loss:

Medical indications are Ear discharge, Ear pain, Irritation or itching in the ear.

Behavioural indications include
o Inconsistent responses to sound
o Does not speak or imitate sound
o Language and speech development is delayed
o Speech is unclear
o Does not follow directions
o Child does not respond when called
o Use of more actions and signs
o Inattentiveness
o Pulling or scratching at the ears
o Play the TV or radio too loudly
o Poor academic performance
o May relies more on speech reading (lip reading)

HRR (high risk register)

This group included infants whose mothers suffered from illness during pregnancy, those who had a family history of hearing loss, or those who were exposed to drugs known to affect hearing. In addition, infants with the following conditions were included for hearing screening:

o Low birth weight, prematurity, oxygen deprivation or breathing difficulties at birth
o Hiperbilirubinemia
o Syndromes associated with hearing loss (Down's syndrome, Turner syndrome)
o Abnormal head or face structures
o Infections such as TORCH (Toxoplasmosis, other Rubella, cytomegalovirus, syphilis herpes)
o Low Apgar scores (which assess several health factors at one and again at five minutes after birth).

HEARING SCREENING PROTOCOL

o BOA (Behavioral Observation Audiometry) checks the infants response to sound stimuli.

o OAE (Otoacoustic emission) This is a relatively quick and non-invasive test. A miniature microphone is placed in the ear. It picks up signals that normally are emitted from the hair cells in the inner ear. This is an excellent screening test for all newborns. If a hearing problem is found, it should be confirmed with the Auditory Brainstem Response test. (ABR/BERA). OAE is of two type : Screening and diagnostic tests
Screening tests – Pass/Refer
Diagnostic tests – Detailed evaluation

o Impedance Audiometry : Test to rule out middle ear problems. It measures the air pressure in the middle ear and the ability of the eardrum to move.

o ABR (Auditory Brainstem Response or BERA (Brainstem Evoked Response Audiometry). In this test, response are obtained from electrical signals passing through nerves involved in hearing. This test is used to screen newborns or to test children unable to cooperate with other methods. Young children often need to be sedated during this test so that their movements don't interfere with the recording.

Babies who are at risk for hearing loss will undergo follow up OAE and ABR with interval of 3 months. At the age of 6 months, hearing impaired baby can receive intervention for better prognosis and to develop the child like normal peers in relevant to development of speech and language.

REFLEX TESTING

Primitive reflexes are reflex actions exhibited from the central nervous system that are shown by normal infants in response to certain stimuli but not by neurologically affected infants. Some of the reflex namely Moro, Rooting, Sucking, Tonic neck, Palmar, Plantar and Babinski reflex. These reflex are checked in association with hearing screening to rule out involvement of neurological disorder in infants.

TREATMENT OPTION

Conductive hearing loss often can be corrected. For example, middle-ear infections and the associated fluid build up can be treated and the child's hearing can be monitored. Surgery may be considered for some problems. Another treatment option for severe or profound sensorineural hearing loss is a cochlear implant. This device is surgically implanted in the skull. It helps to translate sound waves into signals that can reach the brain. Cochlear implants are approved in the United States for use in children older than 12 months of age. Children with significant hearing loss also can learn sign language and lip reading to communicate with others.

Thus, the failure to identify and treat hearing loss by 6 months of age can have serious implications for a child's speech. Even slight hearing loss in one ear can impact a child's speech and language development. Treating a child before 6 months of age can make a huge difference in language and speech development by taking the advantage of critical period.

Early identification and intervention can prevent severe psychosocial, educational and linguistic repercussions. Infants who not identified before 6 months of age have delays in speech and language development. Intervention at or before 6 months of age allows a child with impaired hearing to develop normal speech and language, alongside his or her hearing peers.

(Concluded......)