The suppression occurs in different parts of the emission spectrum, for quantum electrodynamics (QED) small photon energies are suppressed, and for quantum chromodynamics (QCD) large gluon energies are suppressed. In QED the rescattering of the high energy electron dominates the process, in QCD the emitted gluons carry color charge and interact with the medium also. Since the gluons are soft their rescattering will provide the dominant modification to the spectrum.