II. Epidemiology
-
Incidence sensorineural Hearing deficiency
- Newborns: 1-5 per 1000 births
- Age 24 Months: 1 per 25 children (20-50 decibel loss)
- Identify Hearing Loss prior to age 6 months old
- Significant benefit in language development
III. Causes: Infants (Sensorineural Hearing Deficit)
- No risk factors in 50% of infants
- Family History
- In utero infection (CMV, Rubella)
- Low birth weight (<1500 g)
- Hyperbilirubinemia (exchange levels)
- Low APGAR Scores (<5 at 1 min, <6 at 5 min)
- Persistent Pulmonary Hypertension
- Head Injury causing loss of consciousness
- Bacterial Meningitis
-
Ototoxic Medications
- Aminoglycosides (potentiated by Loop Diuretics)
- Chemotherapeutic agents
IV. Causes: Older children (Conductive Hearing Deficit)
- Otitis Media with Effusion (Most common)
- Occlusive foreign body
- Cholesteatoma
- Ossicle disruption
V. Evaluation: Screening
- Timing
- Perform at birth and ages 4, 5, 6, 8, 10, 11 to 14, 15 to 17, and 18 to 21 years
- Formal Hearing Testing if suspicion for Language Delay
- Infants
- Evoked Otoacoustic Emissions (EOAE)
- Sensitivity 50-100%, Specificity 82%
- Easily performed
- Cost: inexpensive ($1 per exam)
- Auditory Brainstem Evoked Responses (ABR)
- Sensitivity 94%, Specificity 89%
- Cost: $30 per exam
- Requires EEG type electrode
- Response to auditory stimulation
- Evoked Otoacoustic Emissions (EOAE)
- Pre-school (Ages 3-5 years)
- Pure tone Audiometry
- Fails if >20 decibel loss at any frequency
- Acoustic immittance testing (Tympanometry)
- Pure tone Audiometry