The effect of aging on middle ear function has not been investigated thoroughly, as there is no simple measuring apparatus except for the conventional impedance meter (IM). However, the reliability of the IM is insufficient, because the stimulus frequency is fixed and the information provided by the IM is minimal. We have developed a sweep frequency middle ear analyzer (MEA), which provides much more information on middle ear dynamic characteristics than a conventional IM, and have obtained various measurements with this device.
In this paper, middle ear dynamic characteristics of 187 normal subjects (309 ears) ranging from a 4-year-old child to an elderly person, 79 years old, were measured with the MEA in the middle ear resonance frequency region where dynamic characteristics can be seen clearly, and the effect of aging on middle ear dynamic characteristics was examined.
The main results obtained were as follows: Middle ear mobilities tend to increase up to the twenties, then decrease up to the forties. Subsequently, a clear difference between those of males and females is observed. The middle ear mobilities of males decrease gradually with an increase in age. In contrast, although the standard deviation values are large, those for females tend to rise with increasing age.
