Not everyone believes that the voices EVP researchers hear are otherworldly spirits. Some skeptics say that EVP is nothing more than radio interference. Others say that people who claim to have heard these voices are either imagining them or else their minds are creating meaning out of insignificant sound, projecting what the person wants or expects to hear on the recording.
"Some of the 'voices' are most likely people creating meaning out of random noise, a kind of auditory pareidolia [the illusion that something obscure is real] or apophenia [mentally connecting unrelated phenomena]," writes Robert Carroll, Ph.D. on his Web site, The Skeptic's Dictionary.
"Humans are exceptionally wonderful at finding patterns in noise," says Edwin C. May, Ph.D., president of the Laboratories for Fundamental Research. "The hardware in our sensory system is designed to see changes in things." So when we hear repeated sounds, our brain picks out and pieces together what sounds to us like spoken words. If you listen to thousands of pieces of audio, Dr. May contends, you'll eventually find one that sounds like a voice. "It's the monkey on the typewriter issue."
EVP researchers counter that the highly interactive communication they have engaged in would be impossible to discount as interference or brain tricks. "I have been an amateur radio operator for 40 years, and I have never had tape or digital recorders pick up any artificial interference," says Oester. "Also, how can an interactive EVP, where the spirit is responding to my questions or commenting on my words, ever be considered interference?"