A 1000 Hz tympanogram on a month-old infant yields a type B result, while a 226 Hz tympanogram yields a type A. The discrepancy is most likely due to

A 1000 Hz tympanogram on a month-old infant yields a type B result, while a 226 Hz tympanogram yields a type A. The discrepancy is most likely due to

• A. Differences in training between the two audiologists
• B. Misinterpretation of the tympanogram by one of the audiologists
• C. Decreased reliability of low-frequency tympanograms on infants
• D. Increased cooperation by the infant during one of the measurements

Answer: (D)

Infant tympanometry is highly sensitive to how still the baby is during the test. When a little one is calm and cooperative, the probe stays well-seated and the pump can accurately measure middle-ear mobility, yielding a reliable result. If the infant is fussy or moving, the seal can break and movement can create artifacts, often producing a flat tympanogram even when the middle ear is normal. In this scenario, one measurement could have been obtained while the infant was more cooperative, giving a normal type A result, while the other was done when the infant was less cooperative, leading to a type B trace. State and cooperation of the infant are common sources of discordant tympanometry results, especially in the neonatal period.

Infant tympanometry is highly sensitive to how still the baby is during the test. When a little one is calm and cooperative, the probe stays well-seated and the pump can accurately measure middle-ear mobility, yielding a reliable result. If the infant is fussy or moving, the seal can break and movement can create artifacts, often producing a flat tympanogram even when the middle ear is normal. In this scenario, one measurement could have been obtained while the infant was more cooperative, giving a normal type A result, while the other was done when the infant was less cooperative, leading to a type B trace. State and cooperation of the infant are common sources of discordant tympanometry results, especially in the neonatal period.