Test-retest reliability of low-level evoked distortion product otoacoustic emissions

Purpose: The purpose of this study was to examine test-retest reliability of low-level evoked distortion product otoacoustic emissions (DPOAEs) as a function of L₁, L₂ level; f₂ frequency; and test condition. A predictive relationship between these variables and the presence/absence of DPOAE responses was also examined. Method: Sixteen normal-hearing young adults participated. DPOAEs were evoked to 12 tones with f₂ frequencies ranging from 1500 Hz to 7546 Hz at 4 L₂ levels between 45 dB SPL and 30 dB SPL. Four test conditions were employed: (a) initial test, (b) retest without probe removal, (c) retest with probe reinsertion, and (d) retest with probe reinsertion by a second tester. Results: L₁, L₂ level and f₂ frequency were statistically significant (p < .0001) predictors of a DPOAE response (i.e., the presence of a DPOAE response was more likely to be observed at higher L ₁, L₂ levels and lower f₂ frequencies regardless of test condition). DPOAE levels were significantly affected by L₁, L₂ level and f₂ frequency (p < .0001) but not by test condition. Intra- and intertester test-retest differences were not significantly different. Conclusions: The prevalence of missing responses coupled with large intersubject variability and intrasubject test-retest variability are a detriment to the clinical utility of DPOAEs evoked with low-level stimuli.