Figure 8.

Case example of a wideband absorbance tympanogram (WBT) in an adult ear with negative middle ear pressure, and otosclerosis. ( A ) The WBT is shown as a three-dimensional plot with absorbance on the vertical ( z -axis), and frequency and static pressure on the horizontal axes ( x - and y -axes, respectively). The violet end of the color spectrum indicates high levels of absorbance, and the red end indicates low levels. The black solid lines indicate absorbance across frequency at −136 daPa, corresponding to the tympanometric peak pressure (TPP). ( B ) Wideband power absorbance (WBA) measurements extracted from the WBT in panel A at two static pressure points: ambient pressure at 0 daPa (WBA ₀ ) and at TPP (WBA _TPP ). Both WBA measurements are reduced in the low frequencies, but the WBA ₀ shows greater reduction below the lower bound of the shaded area of normal (defined in caption of Fig. 5 ) in comparison to WBA _TPP . In addition, WBA ₀ shows a greater high-frequency shift of absorbance maxima.