II. Epidemiology

  1. Incidence sensorineural hearing deficiency
    1. Newborns: 1-5 per 1000 births
    2. Age 24 Months: 1 per 25 children (20-50 decibel loss)
  2. Identify Hearing Loss prior to age 6 months old
    1. Significant benefit in language development

III. Causes: Infants (Sensorineural hearing deficit)

  1. No risk factors in 50% of infants
  2. Family History
  3. In utero infection (CMV, Rubella)
  4. Low birth weight (<1500 g)
  5. Hyperbilirubinemia (exchange levels)
  6. Low APGAR Scores (<5 at 1 min, <6 at 5 min)
  7. Persistent Pulmonary Hypertension
  8. Head Injury causing loss of consciousness
  9. Bacterial Meningitis
  10. Ototoxic Medications
    1. Aminoglycosides (potentiated by Loop Diuretics)
    2. Chemotherapeutic agents

IV. Causes: Older children (Conductive hearing deficit)

  1. Otitis Media with Effusion (Most common)
  2. Occlusive foreign body
  3. Cholesteatoma
  4. Ossicle disruption

V. Screening Tools

  1. Infants
    1. Evoked Otoacoustic Emissions (EOAE)
      1. Sensitivity 50-100%, Specificity 82%
      2. Easily performed
      3. Cost: inexpensive ($1 per exam)
    2. Auditory Brainstem Evoked Responses (ABR)
      1. Sensitivity 94%, Specificity 89%
      2. Cost: $30 per exam
      3. Requires EEG type electrode
      4. Response to auditory stimulation
  2. Pre-school (Ages 3-5 years)
    1. Pure tone Audiometry
      1. Fails if >20 decibel loss at any frequency
    2. Acoustic immittance testing (Tympanometry)

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