Cybus EarPod

EarPod were devices from a parallel universe, created by John Lumic. They could be used to read minds, control them, and add information into them (a daily joke, for example). They were used as the alternate universe's alternative to mobile phones. (DW: Rise of the Cybermen) EarPods were used to induce trance prior to "upgrading" of Humans into Cybermen (DW: The Age of Steel).

When the Cybermen entered this universe, the earpeices of the Torchwood Institute - specifically, Torchwood 1 - allowed control in a similar way, paving the way for the Battle of Canary Wharf. Adeola Oshodi died as an indirect result of this. (DW: Army of Ghosts)

EarPods also exist as a source of private entertainment. (BFA: Cuddlesome)