This method of EVP research is often called the Phone Experiment. This is a real-time method of listening to EVPs while using a telephone. The idea isn't a new one. One of the early pioneers in EVP, Sarah Estep, once recorded a telephone call from a fellow EVP researcher, Konstantin Raudive, who had died 20 years previously.

The idea of hearing the voices of the dead over a telephone has been adapted by modern-day paranormal investigators using modern technology.

During a paranormal investigation, a mobile phone is used to call the phone of another investigator. It is then put into speakerphone mode and placed in an isolated part of the location being investigated.

The investigators then go to another room with the second phone and call out to the spirits, asking questions and encouraging them to answer while listening for responses through the receiving phone.

Sometimes one investigator remains in the room with the...