It all depends on the skill level of the meditators. All forms of energies have an effect on us. It is only to what degree and whether harmful or not. I suppose advanced meditators will not be affected. But for those whose power of concentration is not well developed , the effects may disturb their practice just like how low noise levels can distract /disturb those who are just beginning their meditation practice. As to whether having cell phones around will disturb one's meditation, as long as they are all switched off, I don't think they will ! It is the anticipation of calls which distracts not the objects.