New born hearing screenings
- Part 1 -

Meenakshi Chanu *

Hearing loss is one of the most common congenital anomalies, occurring in approximately 2-4 infants per 1000. Detection of hearing loss in newborns are very important to help their speech language, learning and social development. This is necessary for the children as well as their families and society. So, reliable screening tests that minimize referral rates and maximize sensitivity and specificity are essential.

Newborn Screening for communication Disorder is a program of screening hearing/testing hearing sensitivity carried out in all the newborns soon after their birth for identification of at risk babies for communication disorder. The screening program are conducted by the Department of Prevention ofCommunication Disorder (POCD) at the All India Institute of Speech and Hearing (AIISH) Mysuru. AIISH Mysuru under the Ministry of Health and Family Welfare had launched this project in six centre of India i.e Cuttack, Ajmer, Imphal, Ranchi, Jabalpur and Puducherry. Newborn screening program started in RIMS, Imphal in collaboration with AIISH from the year 2012.

The program is focussed on newborn baby other than children and adults to make early detection/identification and intervention of speech and hearing disorder leading to accomplish good communication skills and better quality of life. Early identification and intervention make the utilization of critical period for development of speech and language skills.

The hearing of newborn can affects by various causes

Prenatal causes (before birth): late pregnancy, ototoxic medication, alcohol, medication, alcohol, cigarette, viral/bacterial infection, Rh incompatibility, TORCH. Natal causes (at the time ofbirth): low birth weight, delayed birth cry, absent birth cry, lack of oxygen supply, hypoxia, Asphyxia, premature, post mature delivery, neonatal jaundice, Hyperbilirubinemia, aspiration of amniotic fluid.

Post Natal causes (after birth): craniofacial structural abnormalities (CLP), congenital condition, convulsions, fits, trauma of head and neck. Young children can lose their hearing after they get some illnesses, including meningitis, encephalitis, TORCH, measles, chickenpox and flu. Head injuries and exposure to very loud noise and some medications can also cause hearing loss.

Aims and objective of Newborn Screening program (NBS)

1. Prevention of hearing loss in newborns
2. Early identification
3. Rehabilitation/Intervention

Programs of NBS

o Awareness program
o Orientation program
o Hearing screening and school screening camps
o Outreach and Extension services

Types of hearing loss

1. Conductive hearing loss
2. Mixed hearing loss
3. Sensorineural hearing loss

Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones (ossicles) of the middle ear. It occurs in newborns o r children with abnormality or deformity in the structure of outer ear canal. Otitis media is also one of the most frequently diagnosed diseases in infants and young children.

The condition can be temporary or permanent and can occur in one or both ears. More commonly, it begins during childhood as the result of middle ear infections. This type of hearing loss present in children with Downs syndrome also.

Sensorineural hearing loss involves problems with the transmission of sound information from hair cells deep within the ear to the nerve that sends sound information to the brain. It is a permanent condition that usually affects both ears. This can be present at birth or it can occur if there is a family history of deafness or the cause is likely to be inherited (genetic).

If the mother had rubella (German measles), cytomegalovirus (CMV), or another infectious illness that affects hearing during pregnancy, the fetus could have been infected and may lose hearing as a result.

Mixed hearing loss is both presence of both conductive and sensorineural.

General identification measures: it can be identify by parent, caregivers who are familiar with baby in their daily living activities. It is often difficult to detect, especially in young children. Following are typical developmental milestones in children with normal hearing. Babies and young children with hearing loss will not achieve these milestons:

Infant's Age      Arousal from sleep for 90 dB SPL
3-4 months      Rudimentary head turn for normal conversation (50-60dB SPL)
4-7 months      Localization to side for soft sounds (40-50 dB SPL)
7-9 months      Localizes to side and in-directly below for a loud whisper (30-40 dB SPL)
9-13 months      Localizes to side and below a loud whisper (30-40 dB SPL)
16-16 months      Localizes to side, below and indirectly above to soft sounds
16-21 months      Localizes directly to the side, below and above to a whisper
21-24 months      Locates directly a sound at any angle to soft sounds.

((To be contd......)