AGE EFFECTS IN MIDDLE EAR REFLECTANCE MEASUREMENT

解剖研究表明，听骨关节和鼓膜随着年龄的增长而变硬。试图使用传统临床阻抗工具量化这些变化的声学后果的研究尚无定论。然而，由于技术限制，这些研究中使用的测量仅限于200至2000赫兹的频率范围。该研究的长期目标是通过将中耳功能的评估扩展到语音辅音感知的一个重要频率区域：2000至6000hz，来表征衰老对中耳的影响。新技术将用于测量比以前更宽的带宽上的能量反射和阻抗：200到10,000 Hz。本文的具体目标是：1)研究年龄对静态宽带能量反射率和阻抗的影响；2)研究年龄对对侧声反射产生的宽带能量反射和阻抗变化的影响。本文将检验两个具体假设：1)中耳高频能量反射率在测压峰值时随年龄增长而增加；2)对侧声反射的宽带能量反射和阻抗模式会随着年龄的增长而变化。第一个假设与高频中耳反射率增加的发展趋势相一致。第二种假设是在数据中提出的，显示了包括镫骨关节随着年龄的增长而变硬，这将改变反射的共振特征。这两种假设都得到了来自年轻人和老年人受试者的试点数据的支持。提出了一种横断面研究，其中静态和反射相关的宽带能量反射和阻抗测量将得到。将使用三组40名受试者，男女人数相等，年龄在18-27岁，40-49岁，60岁以上或等于60岁。方差的双向分析将用于评估不同年龄组和性别的1/3倍频带能量反射和阻抗测量的差异。这些实验数据将为进一步研究中耳功能的发展奠定基础。由于中耳的声学特性已被证明对助听器的性能有巨大的影响，并且由于2300万65岁以上的美国人中约有一半可能是扩音器的候选人，这项研究对这些人的医疗保健质量有影响。

Anatomical studies have shown that the ossicular joints and tympanic membrane stiffen with age. Research attempting to quantify the acoustical ramifications of these changes using traditional clinical impedance tools has been inconclusive. However, the measurements used in these studies have been restricted to the frequency range of 200 to 2000 Hz due to technological limitations. The long-term objective of the proposed research is to characterize the effect of aging on the middle ear by expanding the assessment of middle ear function to an important frequency region for the perception of speech consonants: 2000 to 6000 Hz. New technology will be used to measure energy reflectance and impedance over a wider bandwidth than previously possible: 200 to 10,000 Hz. The specific aims of the current proposal are 1) to examine the effect of age on static wide-band energy reflectance and impedance; and 2) to examine the effect of age on changes in wide-band energy reflectance and impedance produced by the contralateral acoustic reflex. Two specific hypotheses will be tested: 1) that high frequency energy reflectance of the middle ear measured at peak tympanometric pressure increases with age; and 2) that a change in wide-band energy reflectance and impedance patterns of the contralateral acoustic reflex will be observed with age. The first hypothesis is consistent with the developmental trend of increasing middle ear reflectance in the high frequencies. The second hypothesis is suggested in the data showing a stiffening of the incudostapedial joint with age which would alter the resonance characteristics of the reflex. Both of these hypotheses are supported by pilot data obtained from young and elderly subjects. A cross-sectional study is proposed in which both static and reflex-related measures of wide-band energy reflectance and impedance would be obtained. Three groups of 40 subjects will be used, with equal numbers of males and females aged 18-27,40-49 and greater than or equal to 60 years. A two- way analysis of variance will be used to assess differences in 1/3 octave band energy reflectance and impedance measures across age groups and gender. The data from these experiments will lay the groundwork for further studies to examine the development of middle ear function. Since the acoustic properties of the middle ear have been shown to have a dramatic effect on hearing aid performance, and since around one half of the 23,000,000 Americans over the age of 65 may be candidates for amplification this research has implications for the quality of health care for these individuals.