Pareidolia is a peculiarity of our brain wiring whereby it attempts to look for the familiar in the unfamiliar. The burnt toast really doesn’t look like President Obama, we know that. Our brains tell us that it’s an impossibility, however, this doesn’t stop us from seeing something resembling human features in the configuration of light and dark areas of toasted bread.
Likewise, listening the constant drone of rushing water while in the shower can give rise to an experience of an auditory pareidolia (or to be more precise, a paracusis). We may think we hear the phone ringing or snatches of conversation. The white noise of the falling water stimulates the brain to manufacture all sorts of auditory misperceptions.
Scientist Carl Sagan proposed that pareidolia confers on humans an evolutionary advantage, especially where visual stimuli are concerned. He proposed that the human brain has evolved so that it is “hard-wired” to recognise the human face and easily distinguish a myriad variations of the basic features. This allows fast discrimination of friend from foe, but will also allow us to create order out of a chaotic pattern of light and shade, manufacturing a resemblance to a face of patterns on inanimate objects. Pareidolia is perhaps the most innocent form of this tendency of humans to create order out of chaos. (emphasis mine)
