Sun X M, Jung M D, Kim D O, Randolph K J
Department of Surgery, University of Connecticut Health Center, Farmington 06030, USA.
Ann Otol Rhinol Laryngol. 1996 Dec;105(12):982-90. doi: 10.1177/000348949610501209.
Distortion product otoacoustic emissions (DPOEs) at the frequency of 2f1 -f2 (f1 < f2) were measured in 77 human adult ears with normal hearing or sensorineural hearing loss. The purpose of this study was to compare the performances of DPOE tests conducted with two sets of stimuli: 1) L1 = 65, L2 = 50 dB sound pressure level (SPL) re 20 microPa ("65/50"), and 2) L1 = L2 = 65 dB SPL ("65/65"). Half-octave DPOE root-mean-square levels at 1,000, 2,000, 4,000, and 6,000 Hz were computed from the initial DPOEs measured at 0.25-octave intervals. Correlation coefficient and decision-theory analyses were applied to evaluate the DPOE test performance. For both stimuli, DPOE level exhibited significant correlation with pure tone hearing threshold. When the criterion DPOE level distinguishing normal from impaired hearing was adjusted, the curves of sensitivity and specificity crossed, and the values at the crossing were higher than 80% at frequencies of 2,000 to 6,000 Hz for both stimuli. The area under the receiver operating characteristic (ROC) curve, which provides an overall evaluation of the test performance independent of the criterion DPOE level, was .90 or higher at 2,000 to 6,000 Hz for both stimuli. At 2,000 and 4,000 Hz, all measures of test performance were higher for the 65/50 stimulus than the 65/65 stimulus: area under the ROC curve (.96 to .97 versus .90 to .91, statistically significant, p < .001, Wilcoxon test), sensitivity/specificity (90% to 93% versus 80% to 85%), and correlation coefficient (.78 to .87 versus .66 to .79). At 1,000 and 6,000 Hz, the performances of the DPOE tests were similar for the two stimuli. These results support the conclusion that a DPOE test with L1 = 65 and L2 = 50 dB SPL provides a better performance than that with L1 = L2 = 65 dB SPL and recommend the use of stimuli with L1 being higher than L2 by about 15 dB. These results also support a growing view that 2f1-f2 DPOEs can be utilized clinically as a reliable method of testing human sensorineural hearing loss.
在77例听力正常或感音神经性听力损失的成人耳朵中，测量了频率为2f1 - f2（f1 < f2）的畸变产物耳声发射（DPOEs）。本研究的目的是比较用两组刺激进行DPOE测试的性能：1）L1 = 65、L2 = 50 dB声压级（SPL），参考值为20微帕（“65/50”），以及2）L1 = L2 = 65 dB SPL（“65/65”）。从以0.25倍频程间隔测量的初始DPOEs中，计算出1000、2000、4000和6000 Hz处的半倍频程DPOE均方根水平。应用相关系数和决策理论分析来评估DPOE测试性能。对于两种刺激，DPOE水平与纯音听力阈值均呈现显著相关性。当区分正常听力与听力受损的标准DPOE水平进行调整时，敏感度和特异度曲线相交，并且在2000至6000 Hz频率下，两种刺激在相交处的值均高于80%。受试者操作特征（ROC）曲线下的面积提供了独立于标准DPOE水平的测试性能总体评估，在2000至6000 Hz频率下，两种刺激的该面积均为0.90或更高。在2000和4000 Hz时，65/50刺激的所有测试性能指标均高于65/65刺激：ROC曲线下的面积（分别为0.96至0.97和0.90至0.91，具有统计学显著性，p < 0.001，Wilcoxon检验）、敏感度/特异度（分别为90%至93%和80%至85%）以及相关系数（分别为0.78至0.87和0.66至0.79）。在1000和6000 Hz时，两种刺激的DPOE测试性能相似。这些结果支持以下结论：L1 =
