Distortion product otoacoustic emissions: a normative study.

Distortion product otoacoustic emissions (DPOAEs) were quite recently introduced as a new objective auditory screening technique, having a unique potential because of their ability to analyze the micromechanical functions of the cochlea in a frequency-specific way. In 1992, Kemp and Bray released the commercially available Otodynamics Analyzer ILO92, which enabled investigators and audiological centres to perform DPOAE measurements in different populations, but without any relationship to normative data. The purpose of this study was to describe the normative aspects of 2f1-f2 DPOAEs obtained with the ILO92 from 101 normal ears of 101 healthy young adults. The DPOAEs were obtained automatically by means of two data-collection protocols on the ILO92 in the form of DP-gram and DP-growth functions. These data were statistically processed to form a normative database which has the potential of serving as a basis of for further research aimed at determining the utility of DPOAE testing in evaluating ear pathology.