The effects of noise in transient EOAE newborn hearing screening

Abstract

The use of transient evoked otoacoustic emissions (TEOAEs) has been advocated as the first stage entry level technique for universal newborn hearing screening. To date, the majority of TEOAE infant testing has been conducted under controlled noise conditions; i.e., acoustically treated sound suites. As a result, previously reported TEOAE evaluations may not realistically represent test outcomes in actual hospital screening settings. The purpose of this study was to compare the results of TEOAEs with auditory brainstem response (ABR) hearing screening in a hospital environment where noise conditions do not meet the same ambient noise specifications as those found in sound rooms. A total of 119 stable newborns (67 high risk, 52 normal) ranging in post-conceptual age (PCA) from 33 to 41 weeks received both the ABR and TEOAE screening protocols. Testing was conducted at crib side in either the well baby nursery or the neonatal special care unit (NSCU). Newborn ABR screening failed 8 (3.8%) of 224 ears, whereas TEOAE testing failed 85 (38.4%) and could not test another 22 (9.8%) ears. That is, only 117 (52.2%) of the 224 ears passed the TEOAE test. Using the ABR as the reference test the specificity and sensitivity for TEOAE was 52% and 50%, respectively. Noise levels measured by the probe microphone within the ear canal exceeded those levels (30 dBA SPL) recommended for TEOAE newborn hearing screening. Results of this study suggest that under realistic hearing screening test conditions, TEOAE results may be influenced by the level of noise in the testing environment. Whereas significant advances have been attained in TEOAE measurement during the past decade, clinical evidence supports the need for continued research aimed at solving problems before this technique can be used efficiently for newborn screening.