Comparison of Neonatal Transient Evoked Otoacoustic Emission Responses Recorded with Linear and QuickScreen Protocols

Linear and QuickScreen (non-linear) transient evoked otoacoustic emission (TEOAE) protocols were compared in terms of standardized clinical parameters in order to define the protocol producing recordings with the highest signal quality. Neonatal responses (520) were obtained from three different screening sites. The linear recordings were evoked by 69 and 75-dB p.e. SPL clicks. All responses were post-windowed by a 3.5- to 12.5-ms window, chosen by time-frequency analysis as the segment representing 97.35 per cent (linear) and 95.6 per cent (quick) of the total cumulative spectral energy. Evidence from hearing loss cases and the high similarity between the profile contours of the QuickScreen and the linear normal recordings have strongly suggested that a linear response evoked by a 75-dB p.e. SPL stimulus and post-processed by a 3.5 to 12.5 window is free of stimulus artefacts. The data indicate that the 75-dB linear protocol produces higher signal to noise ratios at 2.0, 3.0, and 4.0 kHz, higher wave reproducibility, and lower TEOAE noise values than the QuickScreen protocol.