Longitudinal distortion product otoacoustic emission (DPE) latency changes in preterm neonates

The purpose of this investigation was to determine what types of changes occur in the distortion product otoacoustic emission (DPE) latency with increasing postconceptual age. These DPE latency changes were then described in relation to developmental changes in conductive and cochlear mechanisms in the neonate. Longitudinal DPE latency measurements were obtained from a single ear of 18 preterm neonates. DPEs were evoked at f2s of 3, 4 and 5 kHz. The longitudinal data revealed that DPE latency decreased as a function of postconceptual age for f2 of 3 and 4 kHz, but did not change significantly at 5 kHz. These findings suggest that (1) the conductive and/or cochlear system have not reached maturity in the preterm neonate, (2) DPE latency can be used to measure developmental changes in the auditory periphery, and (3) maturational changes need to be considered if DPE latency is used to identify auditory dysfunction in neonates.