Tognola G, Grandori F, Ravazzani P
CNR Centre of Biomedical Engineering and Department of Biomedical Engineering, Polytechnic of Milan, Italy.
J Acoust Soc Am. 2001 Jan;109(1):283-90. doi: 10.1121/1.1326949.
Scoring of click-evoked otoacoustic emissions (CEOAEs) is typically achieved by the evaluation of the reproducibility of the whole emission and/or within narrow bands. Screening outcomes are influenced not only by the specific combination of the subdivision scheme (i.e., the number, position, and bandwidth of the narrow bands) and the threshold used to determine pass and refer, but also by the accuracy with which the reproducibility is estimated. This study was designed to examine what factors affect the accuracy of the reproducibility estimate and how the accuracy of the reproducibility estimate together with the choice of the subdivision scheme/thresholds affect CEOAE scoring. Simulations with real CEOAEs corrupted with synthesized noise indicated that the reproducibility estimate is influenced by time-windowing and band-pass filtering: the longer the time-window or the broader the bandwidth of the filter, the more accurate the estimate. Quantitative figures on numerical scoring were given in terms of the referral rate and were derived from CEOAEs recorded in a clinical environment from more than 3400 newborns. The narrow bands were extracted according to 12 different subdivision schemes covering the 1.5-4-kHz range. The referral rate was found to depend on the subdivision scheme being used: (i) the worst results were obtained considering four narrow bands at 1.6-2.4-3.2-4 kHz; (ii) the best results were obtained considering two narrow bands at 2.25 and 3.75 kHz; (iii) bandwidths greater than 1 kHz resulted in the lowest referral rates. Also, scoring based on the extraction of four narrow bands produced the most unstable results, i.e., a small change in the threshold might cause even a great change in the referral rate.
瞬态诱发耳声发射（CEOAEs）的评分通常通过评估整个发射信号和/或窄带内的重复性来实现。筛查结果不仅受到细分方案的特定组合（即窄带的数量、位置和带宽）以及用于确定通过和转诊的阈值的影响，还受到重复性估计准确性的影响。本研究旨在探讨哪些因素会影响重复性估计的准确性，以及重复性估计的准确性与细分方案/阈值的选择如何共同影响CEOAEs评分。对添加了合成噪声的真实CEOAEs进行模拟表明，重复性估计受时间窗和带通滤波的影响：时间窗越长或滤波器带宽越宽，估计就越准确。根据转诊率给出了数值评分的定量数据，这些数据来自于在临床环境中记录的3400多名新生儿的CEOAEs。根据覆盖1.5 - 4kHz范围的12种不同细分方案提取窄带。发现转诊率取决于所使用的细分方案：（i）考虑1.6 - 2.4 - 3.2 - 4kHz的四个窄带时结果最差；（ii）考虑2.25和3.75kHz的两个窄带时结果最好；（iii）带宽大于1kHz时转诊率最低。此外，基于四个窄带提取的评分产生的结果最不稳定，即阈值的微小变化可能会导致转诊率甚至发生很大变化。
