Optimal stimulus level conditions for measurements of distortion product otoacoustic emissions

Objective: Distortion product otoacoustic emission (DPOAE) is a tool for an objective examination of the cochlea function. While the clinical applicat ion of DPOEA test is in progress, the measurements vary depending on the st imulus conditions. We aimed to determine the most appropriate stimulus leve l in the clinical application of DPOAE test. Methods: Ninety-seven normal h earing ears and 80 hearing-impaired ears (total 177) were subjected to this study. Two levels of stimulations (L1 and L2) were applied as follows: L1 = L2 = 70 dB; L1 = L2 = 60 dB and L1 = 60/L2 = 50 dB,and DP level was measu red at each stimulation, and compared with hearing level. Results: DP level was highest at L1 = L2 = 70 dB. Normal hearing ears and hearing-impaired e ars were well differentiated at L1 = L2 = 60 dB. Conclusion: In clinical ap plication of DPOAE test, DP levels should be measured at the stimulus level most appropriate for the purposes. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.