Naeve S L, Margolis R H, Levine S C, Fournier E M
Department of Otolaryngology, University of Minnesota, Minneapolis 55455.
J Acoust Soc Am. 1992 Apr;91(4 Pt 1):2091-5. doi: 10.1121/1.403695.
The effect of ear-canal air pressure on click-evoked otoacoustic emissions was measured for pressures ranging from 200 to -200 daPa and stimulus levels ranging from 60-90 dB PeSPL. Positive and negative ear-canal pressures (relative to ambient pressure) reduced the emission amplitude by 3-6 dB. A spectral analysis of the emissions revealed that the effect of ear-canal air pressure is that of a high-pass filter with a cutoff frequency of 2600 Hz and a slope of 4 dB/oct. The spectral changes are the expected effect of an increase in stiffness of the middle ear and were independent of pressure polarity and click level. Ear-canal air pressure substantially reduced the reproducibility of the emission waveform, in many cases rendering the emission indistinguishable from background noise. The implication of these findings for hearing screening applications is that a high false alarm rate may occur in normal-hearing patients with intratympanic air pressures that are significantly different from ambient pressure.
在耳道气压范围为200至-200 daPa以及刺激水平范围为60 - 90 dB PeSPL的条件下，测量了耳道气压对短声诱发耳声发射的影响。相对于环境压力的正、负耳道压力使发射幅度降低了3 - 6 dB。对耳声发射的频谱分析表明，耳道气压的影响类似于一个截止频率为2600 Hz、斜率为4 dB/倍频程的高通滤波器。频谱变化是中耳刚度增加的预期效应，且与压力极性和短声水平无关。耳道气压显著降低了发射波形的可重复性，在许多情况下使耳声发射与背景噪声难以区分。这些发现对听力筛查应用的意义在于，对于鼓室内气压与环境压力显著不同的听力正常患者，可能会出现较高的误报率。
