Tone burst-evoked otoacoustic emissions in neonates: normative data

Vicky Wei Zhang¹ , Bradley McPherson¹ and Zhi-Guo Zhang²

¹Centre for Communication Disorders, The University of Hong Kong, Hong Kong

²Department of Orthopaedics & Traumatology, and Department of Electrical & Electronic Engineering, The University of Hong Kong, Hong Kong

author email corresponding author email

BMC Ear, Nose and Throat Disorders 2008, 8:3doi:10.1186/1472-6815-8-3


Published:	17 April 2008

Abstract

Background

Tone-burst otoacoustic emissions (TBOAEs) have not been routinely studied in pediatric populations, although tone burst stimuli have greater frequency specificity compared with click sound stimuli. The present study aimed (1) to determine an appropriate stimulus level for neonatal TBOAE measurements when the stimulus center frequency was 1 kHz, (2) to explore the characteristics of 1 kHz TBOAEs in a neonatal population.

Methods

A total of 395 normal neonates (745 ears) were recruited. The study consisted of two parts, reflecting the two study aims. Part I included 40 normal neonatal ears, and TBOAE measurement was performed at five stimulus levels in the range 60–80 dB peSPL, with 5 dB incremental steps. Part II investigated the characteristics of the 1 kHz TBOAE response in a large group of 705 neonatal ears, and provided clinical reference criteria based on these characteristics.

Results

The study provided a series of reference parameters for 1 kHz TBOAE measurement in neonates. Based on the results, a suggested stimulus level and reference criteria for 1 kHz TBOAE measures with neonates were established. In addition, time-frequency analysis of the data gave new insight into the energy distribution of the neonatal TBOAE response.

Conclusion

TBOAE measures may be a useful method for investigating cochlear function at specific frequency ranges in neonates. However, further studies of both TBOAE time-frequency analysis and measurements in newborns are needed.