Stimulus-frequency otoacoustic emissions in human newborns

Area of Science:

• Audiology
• Otoacoustic Emissions
• Neonatal Hearing

Background:

• Stimulus-frequency otoacoustic emissions (SFOAEs) are objective measures of cochlear function.
• Understanding auditory development in newborns is crucial for early intervention.

Purpose of the Study:

• To report the first measurements of SFOAEs in human newborns.
• To compare SFOAE magnitudes and phase-gradient delays between newborns and adults.

Main Methods:

• SFOAEs were measured in 15 human newborns at low stimulus levels (≥15 dB SPL).
• Newborn and adult responses were compared during linear growth ranges of SFOAEs.

Main Results:

• Newborn SFOAEs were measurable at low stimulus levels.
• Newborns exhibited phase-gradient delays comparable to adults when normalized for stimulus level.

Conclusions:

• Neonatal cochlear function, as reflected by SFOAE phase-gradient delays, appears mature.
• Adult-like SFOAE delays may compensate for immature middle ear function in newborns.