Top left panel: angle-averaged EBL photon energy density spectra for a homogeneous EBL (solid lines) and in the presence of an accumulation of 10 cosmic voids of radius R = 100 h⁻¹ Mpc each (dashed lines), whose distribution along the line of sight is centered at redshift z_v = 0.3. Green curves indicate locations in front of the ensemble of voids, red curves locations within, and blue curves locations behind. Top right panel: relative deficit of the EBL energy density due to the voids; dashed lines and solid lines represent the effect of voids on the EBL energy density inside and outside the ensemble of voids, respectively. Bottom left panels: EBL γγ optical depth as a function of γ-ray photon energy in the presence of voids (dashed), compared to the homogeneous case (solid), for the same example voids illustrated in the top panels. Bottom right panels: γγ optical depth deficit due to the presence of voids for the same two cases on the left panel.