Vitzthum H G, Weimann S, Scheinpflug L, Vorwerk U, Begall K
Medizinische Fakultät, Universitäts-HNO-Klinik, Otto-von-Guericke-Universität Magdeburg.
HNO. 1997 Dec;45(12):976-82. doi: 10.1007/s001060050182.
The human temporal bone preparation is an acknowledged model for research of the physical processes affecting the outer ear canal and eardrum. Changes affecting the oscillation and resonance behavior of the tympanic membrane and ear canal between death and temporal bone preparation presently exist in only a few studies. Since the influence of age and physique, as well as the width of ear canal on the ear canal resonance may be important, we prepared two separate studies to analyze these questions. The goal of our first test series involved children and was devised to determine if changes in the outer auditory canal resonances differed according to age. In so doing, canal resonance was recorded with a real ear measurement system. Further, we recorded middle ear pressure, impedance of the tympanic membrane, ear canal volume, height, weight and surface of the body, head and ear size. We found a significant decrease in the resonance frequency of the outer ear which was age-dependent and was 2.75 kHz in the 7-year-old child. In a separate study we wanted to know if results found in the postmortem temporal bone reflected in vivo relationships. A tympanometer and real ear measurement system was used to test the resonance behavior of the auditory canal as well as the vibration of the eardrum in dependence on temperature and the time after death for 9 h. We then proved the absence of significant changes in the auditory canal and eardrum oscillation in this time period before possible postmortem changes occurred. Our findings show that the method of bone preservation after its preparation is decisive for the validity of measurements in the isolated human temporal bone.
人类颞骨标本是研究影响外耳道和鼓膜物理过程的公认模型。目前仅有少数研究探讨了从死亡到颞骨标本制备期间影响鼓膜和外耳道振荡及共振行为的变化。鉴于年龄、体格以及外耳道宽度对外耳道共振的影响可能至关重要，我们开展了两项独立研究来分析这些问题。我们的首个测试系列针对儿童，旨在确定外耳道共振的变化是否因年龄而异。在此过程中，使用真耳测量系统记录外耳道共振情况。此外，我们还记录了中耳压力、鼓膜阻抗、外耳道容积、身高、体重以及身体、头部和耳朵的表面积。我们发现外耳道共振频率显著下降，且与年龄相关，7岁儿童的共振频率为2.75千赫兹。在另一项研究中，我们想了解死后颞骨的研究结果是否反映了活体中的关系。使用鼓室图仪和真耳测量系统，测试了9小时内耳道的共振行为以及鼓膜振动随温度和死亡时间的变化。然后我们证明在此时间段内，在可能出现死后变化之前，耳道和鼓膜振荡没有显著变化。我们的研究结果表明，颞骨制备后的保存方法对于孤立人类颞骨测量的有效性至关重要。
