AGE EFFECTS IN MIDDLE EAR REFLECTANCE MEASUREMENT

解剖学研究表明，听骨关节和鼓膜随着年龄的增长而变硬。试图使用传统的临床阻抗工具来量化这些变化的声学影响的研究一直没有定论。然而，由于技术限制，这些研究中使用的测量被限制在200至2000赫兹的频率范围内。这项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重要频率区域：2000至6000赫兹，来表征衰老对中耳的影响。新技术将被用来在比以前更宽的带宽上测量能量反射率和阻抗：200到10,000赫兹。目前建议的具体目的是1)研究年龄对静态宽带能量反射和阻抗的影响；以及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。两个具体的假设将被检验：1)在峰值鼓室压下测量的中耳的高频能量反射率随着年龄的增加而增加；以及2)对侧声反射的宽带能量反射率和阻抗模式将随着年龄的变化而观察到变化。第一个假说与高频段中耳反射率增加的发展趋势相一致。第二个假设是在数据中提出的，该数据显示随着年龄的增长，砧骨关节僵硬，这将改变反射的共振特征。这两个假设都得到了从年轻人和老年人那里获得的试点数据的支持。提出了一项横截面研究，其中将获得宽带能量反射率和阻抗的静态测量和反射相关测量。将使用三组40名受试者，年龄在18-27岁、40-49岁和大于或等于60岁的男性和女性人数相等。将使用双向方差分析来评估1/3倍频程能量反射率和阻抗测量在不同年龄组和性别之间的差异。这些实验的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显著影响，而且由于2300万65岁以上的美国人中约有一半可能是扩音器的候选者，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.