Department of Communication Sciences and Disorders, Wichita State University, Wichita, KS 67260–0075, USA.
Int J Audiol. 2013 May;52(5):333-41. doi: 10.3109/14992027.2012.759664. Epub 2013 Jan 23.
To test the assumptions concerning the compensation of middle ear pressure (MEP) in using peak Y(tm) and the tympanogram asymmetry phenomenon, and to address the variability and reliability of 226 Hz tympanometry under negative MEP.
(1) Repeated measures in normal ears with experimentally-induced negative MEP; (2) Retrospective analysis of clinical data from ears with negative MEP.
Experimental data: 57 adult ears.
200 adult ears.
Mean peak Y(tm) significantly increased (˜ 0.10 mmhos) under negative MEPs (> - 190 daPa). TW increased, up to ˜50 daPa, for MEP ≤ - 130 daPa. V(ea) decreased when MEP ≤ - 190 daPa. With increasing negative MEP, peak Y(tm) and tympanogram gradient tended to decrease. The within-subject variation of all measures and difference between normal and negative MEP were small.
The tympanometry procedure increases peak Y(tm )in ears with low to moderate negative MEP, and decreases gradient and V(ea) with high negative MEP. This is referred to as hypercorrection of the admittance and should be accounted for in clinical norms. Results imply that tympanogram asymmetry is due to divergent effects of air pressure on the middle ear. The variability of tympanometry does not increase and reliability not decrease under negative MEP.
测试关于中耳压力（MEP）补偿的假设，使用峰 Y(tm) 和鼓室图不对称现象，并解决在负 MEP 下 226 Hz 鼓室图的可变性和可靠性。
（1）在实验性负 MEP 下对正常耳朵进行重复测量；（2）对负 MEP 耳朵的临床数据进行回顾性分析。
实验数据：57 只成人耳朵。
200 只成人耳朵。
在负 MEP 下（＞-190 daPa），平均峰 Y(tm) 显著增加（约 0.10 毫西门子）。当 MEP ≤-130 daPa 时，TW 增加至约 50 daPa。当 MEP ≤-190 daPa 时，V(ea) 降低。随着负 MEP 的增加，峰 Y(tm) 和鼓室图梯度趋于降低。所有测量值的个体内变异性和正常与负 MEP 之间的差异都很小。
在低至中度负 MEP 的耳朵中，鼓室图程序增加了峰 Y(tm)，而在高负 MEP 下则降低了梯度和 V(ea)。这被称为导纳的过度校正，应在临床规范中考虑。结果表明，鼓室图不对称是由于气压对中耳的发散作用所致。在负 MEP 下，鼓室图的变异性不会增加，可靠性也不会降低。
