Bat Detectors For EVP?
Monday February 25, 2008 8:35 AM
Not getting enough EVP bang out of your digital recorder? Try a bat detector!
It's true — devices made to pick up the ultrasonic soundings of bats can record electronic voice phenomena (EVP), the imprints of disembodied voices not heard but registered on recording equipment. The bat detectors don't often pick up as much as a digital recorder, but success with them demonstrates that the dead and spirits don't need magnetic tape or digital recording technology to leave messages.
Bat detectors operate at much higher frequencies of sound waves than can be detected by the human ear. The human hearing range is from 20 hertz (hz) to about 20 kilohertz (khz), which are the number of vibrations made per second. Bats emit ultrasounds between 12 khz and 100 khz, and some even as high as 160 khz. There are two types of bat detectors. One is a super heterodyne, which tunes to specific frequencies. The other is a down-converter, which transforms bat pings to sounds that can be heard by the human ear. The second type of bat detector is the one suited to EVP.
Rick Fisher is one paranormal investigator who has added a down-converter bat detector to his tool bag. Fisher, the founder of the Paranormal Society of Pennsylvania, had one built for him by Craig Telesha, the creator of Ghost-Tech. The bat detector has a microphone output jack for connection to a recorder.
Fisher has experimented with his bat detector at home and at haunted locations. He runs it at the same time with his digital recorders. He has even experimented with putting both devices inside a non-operating microwave oven, a sort of makeshift Faraday cage that screens out electromagnetic interference.
EVP voices picked up by the bat detector are of comparable quality to the voices picked up by digital recorders. Fisher gets different messages via the bat detector.
Bat detectors may seem novel, but the inspiration for using them is decades old. Franz Seidl, the inventor of the Psychophone EVP device, once posited that many EVP voices might be beyond the range of human hearing.
Fisher's success indicates that how ever the voices are imprinted, they cover quite a range of frequencies. Investigators may be missing out on a large spectrum of EVP activity because of the limitations of digital and magnetic tape recorders.
