Various tools are used to obtain hard evidence of paranormal activity. These include:
- Still photography, which may capture odd lines, circles, or marks.
- Video cameras, which may capture odd movement, often in a human form.
- Audio recordings, which capture odd sounds or voices (see Electronic Voice Phenomenon, below). The audio track of video recordings may also record abnormal activity.
- Electromagnetic sensors: areas believed to contain paranormal activity often have electromagnetic fluctuations.
- Temperature measurements, especially infrared video cameras, may show pockets of extreme temperature differences. In the case of a video camera, spots of different temperatures may appear to be human-shaped.
Sometimes, psychics are employed to communicate with spirits; however, this is not considered to be evidence, as their statements cannot be confirmed. The evidence must be all-inclusive to show that there wasn't alteration of it, for example, an audio recording alone might be done via whispering into a microphone. If, however, the audio taping was also on video, it could be confirmed that it was an open microphone.
Electronic Voice Phenomenon
One method that is widely used, and an easy and cheap means of communication, is by searching for voices via an audio recording. This is known as Electronic Voice Phenomenon, or EVP. Ghost hunters often allow a recorder to record while they ask a perceived ghost questions, hoping to find an answer on the tape. Voices may be quiet, muffled, or otherwise difficult to understand, though numerous recordings of high quality have been made, semi-validating this practice.
EVP is observed through recording some type of background noise- it is believed that voices modulate from this noise. Often, low quality equipment is used, as this equipment introduces background noise. Other methods include using a running electrical appliance (e.g. fans) or a radio or television not tuned to a station. Using a non-tuned television or radio is not a reliable means, as a weak signal on this device could be picked up. There has been an instance, however, of a tuned radio picking up an EVP- a radio was tuned to a French station, and the words modulated to English.
Opponents take several issues with EVP. First, many produced recordings can't be proven to be authentic. Often, to show that there was no tampering, a video recording will be made showing the audio recording/playback taking place, though more intricate forgeries could circumvent this. Also, there is the potential for the sound to be background noise, white noise, or others' voices caught on the recording (supporters often argue that the EVP answers a question asked, therefore, it is too great of a coincidence for an unrelated voice to match). Additionally, many skeptics argue that there is no voice response at all- that the brain is misinterpreting mere noise to be something greater, a phenomenon known as Auditory pareidolia.
Examples of captured paranormal activity
- Video: Video which, assuming it is authentic, captured a human-shape figure moving in a parking garage, appearing and disappearing.
- Audio: Page with multiple EVP recordings. Again, their authenticity can not be verified, except by those who were present.
- Photos: Page showing photos purported to show abnormalities.