Mean (upper panel) and maximum (lower panel) detection levels in mocks (black histogram) and in 100 realizations of 2MRS voids. In the same way as in Fig. 8, we calculated the mean and maximum detection levels taken over the different parameter variations shown in Table 1 for the void sets of each individual mock catalogue and for 100 SPARKLING void realizations based on 2MRS data. All temperatures were calculated on the actual Planck SMICA CMB map and significances calibrated on the corresponding CMB simulations.