Microphones are incredibly common electronic appliances. They are utilized in telephones, on headsets for computers, in hearing aids, in tape decks, in megaphones, for VoIP purposes and much more. Microphones work on very well understood electrical principles and are actually very old devices. Depending upon what you actually consider a microphone, there are varying ways to look at when they were invented and their overall history. Microphones, despite the fact that they are audio equipment, are also designed with aesthetics in mind. The many different types of microphones include designs that are intended to be easily hidden from view, which makes them particularly useful for video and live theater productions.