## 3 Results  
### Representative Shape Measurement Results  
The MWHI method has been verified to reach an accuracy of 0.045 mm and exhibited repeatable measurements with 17 \(\upmu\)m accuracy on a (National Institute of Standards and Technology) traceable ball and artificial samples [31]. This paper presents the results of TM shape measurements from three post-mortem human temporal bones (TB3, TB4, and TB5) under different manipulations. The 3D shapes of the TM of the three samples measured with a closed middle-ear cavity are shown in Figure 3a-c with laser continuous wavelength tuning from 779 to 779.4 nm (i.e., maximum synthetic wavelength  
Figure 2: (**a**) Shows the setup, measuring instrumentations, and the sample; and (**b**) is a photograph of the human postmortem tympanic membrane (TM) with half level saline injected. The yellow contour shows the level of fluid. (**c**) Shows the incudo-stapedial (IS) joint. The red dash shows where the IS joint is interrupted. 1.7 mm), while N (N = 17) of phase samplings are performed to capture the optical phase at different wavelengths during wavelength tuning. The depth of the TM is rendered by color as shown in the color bar, where the TM annulus is set as zero (yellow), and the value increases negatively towards the middle-ear cavity side. In Figure 3d-h, the difference of the TM shape along the solid black line across the TM surface, as shown in Figure 3a, between the closed cavity (as reference) and different manipulations are shown. The comparison between the open cavity and the closed cavity shows no significant TM shape change in all three TBs (Figure 3d). The fluid injection induces more significant TM shape change where the fluid in contact with the TM pushes the TM surface outwards towards the ear canal side, yielding positive TM shape change values as shown in Figure 3e,f. Note in Figure 3e only half of the TM (to the right side of the plot) is in contact with the fluid. Stages immobilization did not introduce significant TM shape change, as shown in Figure 3g. The IS joint interruption induced more significant changes to the TM shape which generally occurred at the posterior part of the TM, and the direction of the shape change was towards the middle-ear cavity (as shown in negative values in Figure 3h). We used the shape information to derive TM transient surface-normal displacements. We investigated using the root mean square (RMS) of the motion of the entire TM surface to define an indicator to evaluate and distinguish different middle-ear manipulations. We also compared the umbo displacement in the time domain among different middle-ear manipulations. Figures 4-6 show the RMS of TM surface motions over the first 3 ms after the TM receives the acoustic excitation for three TBs--under different middle-ear conditions. Figures 7-9 show the umbo motion during the same time period under different manipulations for three bones. From the RMS results, we observed that an open cavity case always has a more complex distribution of the RMS than a closed cavity case. For half fluid injection cases, only the area not in contact with fluid shows significant RMS values of motion (right side of the TM in Figures 4c and 5c and left side of the TM in Figure 6c, the difference is caused by the different sides of the ear these specimens come from (TB3: 75 year old female, left ear; TB4: 61 year old male, left ear; TB5: 76 year old female, right ear)). When the middle-ear cavity is fully filled with fluid, the RMS value of TM motions is almost zero. Stages immobilization and IS joint injection exhibit RMS motion patterns that are similar to those observed in the normal case. The umbo displacement profiles with time show distinguishable differences among different middle-ear conditions for all three bones, as shown in Figures 7-9. In an open cavity case, the umbo undergoes more periods of motion compared to a closed cavity case, or umbo motion damps out faster in the closed cavity case.