THE EFFECTS OF NOISE IN TRANSIENT EOAE NEWBORN HEARING SCREENING

The use of transient evoked otoacoustic emissions (TEOAEs) has been ad vocated 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 t reated sound suites. As a result, previously reported TEOAE evaluation s may not realistically represent test outcomes in actual hospital scr eening 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 amb ient noise specifications as those found in sound rooms. A total of 11 9 stable newborns (67 high risk, 52 normal) ranging in post-conceptual age (PCA) from 33 to 41 weeks received both the ABR and TEOAE screeni ng protocols. Testing was conducted at crib side in either the well ba by nursery or the neonatal special care unit (NSCU). Newborn ABR scree ning 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 referen ce test the specificity and sensitivity for TEOAE was 52% and 50%, res pectively. Noise levels measured by the probe microphone within the ea r canal exceeded those levels (30 dBA SPL) recommended for TEOAE newbo rn hearing screening. Results of this study suggest that under realist ic 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 decad e, clinical evidence supports the need for continued research aimed at solving problems before this technique can be used efficiently for ne wborn screening.