Ghost rapping became a huge phenomenon during the Victorian era and still persists today.
Many skeptics say that these ‘rappings’ are just clever hoaxing and can be easily duplicated. Others are firm believers that it is a form of spirit communication.
Dr Barrie Colvin, a polyurethane technologist who carries out experimental psychical research, has analyzed the audio recordings of several notorious ghost rapping cases, and believes they share similar acoustic qualities to an earthquake.
This week he will be holding a lecture at the University of Glasgow where he will present his evidence to the public.
According to Colvin, on analysis, these sounds give a distinct sound signature when compared to recordings of rapping sounds made in ordinary ways, such as knuckles hitting a wall.
He found that while the sound of a normal rapping noise is loudest at the start and fades over a period of milliseconds, the paranormal rapping starts relatively quietly before becoming loud and then fading away.
This audio is mostly closely related to the waves from an earthquake.
Psychology experts have welcomed Colvin’s “interesting observations” but stressed that while they cannot be readily dismissed, nor do they offer conclusive proof of ghostly activity.