Stepp Cara E, Voss Susan E
Picker Engineering Program, Smith College, 51 College Lane, Northampton, Massachusetts 01063, USA.
J Acoust Soc Am. 2005 Aug;118(2):861-71. doi: 10.1121/1.1974730.
The impedance of the middle-ear air space was measured on three human cadaver ears with complete mastoid air-cell systems. Below 500 Hz, the impedance is approximately compliance-like, and at higher frequencies (500-6000 Hz) the impedance magnitude has several (five to nine) extrema. Mechanisms for these extrema are identified and described through circuit models of the middle-ear air space. The measurements demonstrate that the middle-ear air space impedance can affect the middle-ear impedance at the tympanic membrane by as much as 10 dB at frequencies greater than 1000 Hz. Thus, variations in the middle-ear air space impedance that result from variations in anatomy of the middle-ear air space can contribute to inter-ear variations in both impedance measurements and otoacoustic emissions, when measured at the tympanic membrane.
在三只具有完整乳突气房系统的人类尸体耳朵上测量了中耳气腔的阻抗。在500赫兹以下，阻抗近似于顺应性，而在较高频率（500 - 6000赫兹）时，阻抗幅值有几个（五到九个）极值。通过中耳气腔的电路模型识别并描述了这些极值的机制。测量结果表明，在高于1000赫兹的频率下，中耳气腔阻抗对鼓膜处的中耳阻抗影响可达10分贝。因此，当中耳气腔解剖结构变化导致中耳气腔阻抗发生变化时，在鼓膜处进行测量时，这可能会导致两耳在阻抗测量和耳声发射方面出现差异。
