Spectral Composition of Infant Auditory Brainstem Responses: Implications for Filtering

Abstract

Auditory brainstem responses (ABRs) were recorded from 20 normal neonates and 10 normal-hearing adults. The spectral compositions of ABRs from both groups were compared. Results indicated that significant amounts of low-frequency information are concentrated below 150 Hz in both the neonate and the adult ABRs although the neonate ABR has a slightly greater percentage of low-frequency information than that of the adults. This has implications for filtering during ABR recording. A low high-pass setting which preserves more of the low-frequency information will allow enhanced detectability of wave V in neonate ABRs recorded at low stimulus intensities. Furthermore, our experience indicates that the use of a 30- to 3000-Hz bandpass is feasible in the neonatal intensive care unit as well as in the regular newborn nursery. Therefore the use of a 30- to 3 000-Hz bandpass is recommended for neonate ABR recordings.

Key Words:

• Auditory brainstem response
• Spectral composition
• Infant
• Adults
• normal
• Filtering
• Wave V amplitude