1. An external medical device, comprising: a housing; an energy storage module within the housing for storing an electrical charge; a defibrillation port for guiding via electrodes the stored electrical charge to a person; a user interface structured to deliver prompts to a user during a defibrillation session; and a language detector in the housing structured to determine a vicinity language, in which the prompts delivered by the user interface to the user during the defibrillation session are in a language that is selected based on the determined vicinity language, and further in which the language detector includes an optical character recognition (OCR) module, or both a voice recognition module and an OCR module.