OAE & BERA Test – नवजात शिशु Hearing Screening Hardoi

Congenital Hearing Loss – समस्या को समझें

Statistics:

• Incidence: 1-3 per 1000 live births में congenital hearing loss
• Most common birth defect affecting sensory system
• 50% cases: Genetic
• 25% cases: Prenatal infections (TORCH), complications
• 25% cases: Unknown cause

Timely screening and follow-up:

• By 1 month: complete newborn hearing screening
• By 3 months: complete diagnostic audiology if the baby does not pass screening
• By 6 months: enroll a child with confirmed hearing loss in appropriate early-intervention services
• Continue developmental and hearing follow-up because some hearing loss can appear or progress later

Why delayed identification matters:

• Hearing loss can affect speech and communication development.
• Language development may be delayed without timely access to appropriate support.
• Some children may experience learning difficulties.
• Communication barriers can affect social participation.
• Educational needs vary and should be assessed individually.
• Outcomes vary; screening must be followed by individual audiology assessment and monitoring.

How early intervention can help:

• Early services can support communication, language and social development.
• Hearing aids, cochlear-implant evaluation or other options depend on the confirmed hearing profile and specialist assessment.
• Family-centred communication support and ongoing follow-up are important.
• No test or intervention guarantees a particular speech outcome.

Sources: CDC newborn hearing screening guidance and ASHA newborn hearing screening guidance.

OAE (Otoacoustic Emissions) Test

What is OAE?

Otoacoustic Emissions are sounds produced by outer hair cells in cochlea (inner ear) when they’re functioning normally. यह एक natural phenomenon है – healthy cochlea “echoes” produce करता है।

How OAE Test Works:

Procedure:

• एक small soft probe ear canal में रखा जाता है
• Probe delivers clicking sounds या pure tones
• If cochlea healthy → outer hair cells vibrate → produce echoes
• Probe में microphone है जो इन echoes को record करता है
• Computer analyzes और result देता है

Result:

• PASS: OAEs present = Cochlea function normal (hearing likely normal)
• REFER: OAEs absent/weak = Needs further testing (BERA)

Advantages:

• Very quick: 5-10 minutes both ears
• Non-invasive: Completely painless
• No cooperation needed: Baby can be asleep!
• Excellent screening tool
• Can be done within 24-48 hours of birth

Limitations:

• Only tests up to cochlea (inner ear)
• Doesn’t check auditory nerve या brain
• Can give false “refer” if:
  • Middle ear fluid present (common in newborns first few days)
  • Wax/vernix in canal
  • Baby crying/moving
• If refer → needs BERA for confirmation

When to Do OAE:

• Universal newborn hearing screening: Ideally all babies within 1 month of birth
• High-risk babies: Especially important if:
  • Family history of hearing loss
  • NICU admission >5 days
  • Birth asphyxia
  • Maternal infections (TORCH)
  • Ototoxic medications
  • Craniofacial abnormalities

BERA (Brainstem Evoked Response Audiometry) / ABR (Auditory Brainstem Response)

What is BERA?

BERA एक advanced test है जो complete auditory pathway check करता है – inner ear से brain तक। यह brain waves record करता है in response to sound।

How BERA Works:

Principle:

• जब sound ear में जाती है → inner ear → auditory nerve → brainstem → brain
• इस pathway के different points पर electrical activity generate होती है
• BERA इन electrical responses को record करता है

Procedure:

Step 1: Preparation

• Baby को feed करें, diaper change
• Baby should sleep (natural sleep या sedation – doctor decides)
• Small electrodes scalp पर लगाए जाते हैं (painless, skin पर stick)

Step 2: Sound Delivery

• Headphones/earphones से clicking sounds deliver होती हैं
• Different intensities (loud to soft)
• One ear at a time

Step 3: Wave Recording

• Electrodes brain waves record करते हैं
• Computer averages hundreds of responses
• Generates waveform

Step 4: Analysis

• Waveforms को अन्य hearing findings और clinical context के साथ interpret किया जाता है
• Waves present हैं? At what intensity?
• Latencies normal हैं?

Result Interpretation:

Normal BERA:

• Waves present at normal intensities (20-30 dB)
• Wave latencies normal
• Indicates: Hearing normal from ear to brain

Abnormal BERA:

• Waves present only at high intensities → Hearing loss
• Degree measured: Mild, moderate, severe, profound
• Can quantify loss (approximately)

No waves:

• Profound hearing loss OR
• Auditory neuropathy (nerve problem despite normal cochlea)

BERA Advantages:

• Objective: No patient response needed
• Tests entire pathway: Ear to brain
• Quantifies loss: Approximate degree
• Can do in babies (sleeping)
• Guides hearing aid fitting
• Detects auditory neuropathy (OAE misses this)

When BERA is Done:

• OAE refer: Confirmation needed
• High-risk newborns: Direct BERA sometimes
• Cannot do behavioral testing: Very young babies, uncooperative children
• Pre-hearing aid fitting: In infants
• Suspected auditory neuropathy

Newborn Hearing Screening Protocol

Recommended Timeline:

Birth to 1 Month:

• OAE screening for all newborns (ideally before hospital discharge)

If OAE “Refer”:

• Repeat OAE at 1 month (could be temporary middle ear fluid)
• If still refer → BERA by 3 months

If BERA Confirms Hearing Loss:

• For confirmed hearing loss, arrange early-intervention services by 6 months:
  • Discuss communication support with the family
  • Consider hearing devices or cochlear-implant evaluation only when individual audiology and medical assessment supports them
  • Arrange developmental, audiology and ENT follow-up as advised
  • Use a family-centred early-intervention plan

What Parents Should Do

हर बच्चे को Screen करवाना चाहिए:

• Even if no risk factors
• Early detection = Key to normal development

Watch for Signs (Even if Screening Normal):

• By 3 months: Should startle to loud sounds
• By 6 months: Turn to sound source
• By 12 months: Simple words (mama, dada), respond to name
• If any delay → Get tested!

High-Risk Babies – Extra Vigilant:

• Even if pass screening, can develop late-onset hearing loss
• Regular follow-ups needed