But there may be another explanation. No one is suggesting that the police officers made up the story of the mysterious voice. However illusory voices and signs of life can be created by well-understood psychological process called apophenia, which cause people to “hear” distinct sounds and voices in random white noise patterns such as the background static in an audio recording –like hearing a non-ringing doorbell or the telephone while in the shower.
For example in June 2012, customs officials at a New Jersey port stopped and searched a cargo ship for dozens of hidden stowaways. According to an ABC News report:
“The ordeal began around 3 a.m. Wednesday, after a Coast Guard patrol stop at the mouth of New York harbor, when officials conducting a routine check of the cargo ship believed they may have heard faint knocking coming from one of the containers onboard…. The ship had been out to sea for more than two weeks prior to docking, leading authorities to fear for the health of the alleged stowaways.” Not only had the officials heard knocking from the container, but they also believed that the stowaways were responding to their calls and requests: “officers heard noises ‘consistent with the possible presence of stowaways’ coming from one of the containers in the ship’s hull, said Charles Rowe, a Coast Guard spokesman. ‘When we knocked, we heard a knock back,’ he said.”
After over 150 cargo containers had been opened and thoroughly examined, the search was called off. No one was found, either at the time or in the following weeks. It had all been a mistake, a sincere misunderstanding. The knocking that the customs agents believed was created by humans was not.