One of the most fascinating and most understood is the EVP
(Electronic Voice Phenomena)
Even though this phenomena has been know for many years, the theories as to their origins are countless. Imagine capturing an unknown voice that has directly interacted with your present actions. Almost always these unknown voices are not heard with your ears, however they are recorded by recording equipment. Some may be faint and others loud and clear as if something was standing right next to you.
It is not our intention to steer anyone to a specific theory nor give you a solid explanation as to their origin. What we wish to present to you are EVPs that have shown direct interaction.