Spatial difference maps e^t of the VN according to equation (38) for the baffled circular piston in Figure 3b vibrating at f=1 kHz. The top row (a–f) shows the spatial difference between the even VN layer outputs q^t of Figure 9(g–l) and the ground truth reference q_ref=q_true in Figure 3b. The bottom row (g–l) shows the spatial difference between curated VN layer outputs q^t and their respective layer inputs q_ref=q^t−1.