| EVP's. What you (possibily) didn't know... |
[28 Mar 2008|05:02pm] |
by Matt Ferrell
2008
--------------------------------
Preface
EVP's (electronic voice phenomena) have become one of the more popular ways to capture what some deem evidence of ghosts/hauntings. Almost all the paranormal investigative groups have audio recorders in their equipment bag. Basically, it's taking an audio recorder, recording at a location, then on playback they listen for any odd voices they didn't hear at the time. If they are heard, and you don't remember hearing them at the time, some say it could be a ghost. This idea of trying to communicate to the dead is nothing new though. Thomas Edison was even in on it. In the 1920's he was trying to invent a machine that would communicate with ghosts, like a "telephone to the dead". Unfortunately, he died before acquiring that goal.
Now, this article isn't going to be about how to capture EVP's. There's loads of those articles out there. And they're all basically the same. They tell you to record something, then play it back, and tada, You might have a ghost! And most places also give the same tips, like what questions you can ask (some EVP's reply to your questions), always use new tapes when recording (so you don't get past recordings bleeding through), and even how to edit/enhance your recording in audio editing software. So no, I'm not writing about that. I'm also not writing this to say EVP's aren't ghosts. I know I'm skeptical, but I'm still open minded. Just with any way to capture evidence, I'm open to the possibility that it may work in capturing some form of evidence of the unknown. But I'm also looking at logical explanations. If we're just looking for ghosts, and not applying any logical thinking to critique our findings, then we will find ghosts all over the place! If we gain knowledge and critique our findings through that knowledge and are still left with unanswered questions, that's alot more interesting then just not critique much at all and jumping at everything as paranormal evidence, right?
And that's one of the problems with the paranormal field today. People run around with equipment because they've heard it may capture a ghost. Some even go as far as saying they're "scientifically investigating" ghosts just because they're waving electronic equipment around, but they themselves don't really know the ins and outs of the equipment they're using. Some take photos, but have little to no knowledge of photography, so if they see something odd in the photo, they may deem it as paranormal when it's not. They wave an EMF (electro magnetic field) meter around, but they have little to no knowledge of electricity or electro magnetic fields, so if they get a fluctuation that they can't explain, they think it may be paranormal. And the same goes with EVP also. They take an audio recorder into places, record, then playback and hear something odd.. but they have little to no knowledge of how audio works, of frequencies, etc. Ask most researchers what the frequency response of their recorder is, and they'll give you a blank stare.
Now I'm not saying you need to know every bit of knowledge of every bit of equipment your team uses or anything. That'd be alot of knowledge to take in (but it is possible). A smart thing to do would be to set people on certain equipment. One person specializes on EMF's, one on audio, one on photography, etc. Some teams bring in people just for this purpose. Even if the person doesn't believe in ghosts, they may still have great knowledge of EMF's, etc. So they'll be a great help! But with most teams, you'll see every investigator juggling around equipment left and right, despite having little to no knowledge of what they're actually holding in their hands or how it works.
So no, I'm not writing this to say it isn't possible to capture ghosts on audio recorders, because it very well might be. And I'm not writing this to tell you how to capture a ghost on an audio recorder. There's lots of sites/information out to give you ideas into that. I'm writing this to give some more info into audio, recordings and the human mind itself. The more knowledge you have on a subject, the better you can critique your data.
Perception / Cocktail Party Effect
I won't get into the technical side of things yet. I'll start off simple. A big thing in EVP research is people saying how they "didn't hear it at the time, but it's on the recorder" and saying this is the reason why it could be paranormal. Now, there's been alot of research into how humans experience things/how human perception works. Our bodies filter out things. Things we feel, things we see, things we hear, etc.
There's a video where a group of people are playing basketball (or really, just throwing a ball around). People were asked to watch the video and count how many times the people in white passed the ball. Almost all report just seeing a group of people playing basketball, and are able to tell how many times the people in white passed it to each other. Then the people are asked to watch it again, and on the 2nd viewing, you can see a person in a bear suit moonwalking through the people. Your brain filters out the bear the first time because it's busy doing something else. Even when you've seen it the 2nd time, and you now KNOW the bear is there, if you focus on the passes, you may not see it. This video can be seen here.
The same thing can happen with audio. Some call it the Cocktail Party Effect. Imagine being in a room full of people with loud music and everyone talking. For the most part, it's all just sounds that you're not able to easily make out. But then you hear someone call your name. Your brain filtered out your name from the noise because it was relevant to you. Now what if you were to record the party sounds and listen to them later on? You may hear words on the recording that you didn't hear at the time. It's not because the words weren't there. They were. They were all over! Your brain just didn't hear it at the time. It filtered it out.
Now, okay. Most ghost investigators don't record in loud settings. It's quiet. Then on the recording you hear a voice. But it was quiet, so you should of heard it at the time, right? Not necessarily. Your brain can still filter out things. Just as when your brain is focused on the tosses in the video, you miss something.. the same may happen in audio. You could of been focusing on EMF readings. Or taking notes. Or even just thinking of the next question to ask, or lost in some other thoughts. Your brain is always working, even as we sleep. So to say a sound is paranormal just because you didn't hear it at the time (but it's on the recording), is a weak argument. When reviewing audio, you're focusing on reviewing the audio. So you're more likely to hear something you didn't before. Because before, you had people around you doing things, you yourself were doing things, etc. Even if you think you're totally focused on hearing and asking questions, there's still the chance your brain will filter out something/you'll miss it.
It can also go the other way though. Just as your brain can see images in the clouds, it may also hear sounds that aren't really what they are. Our brain is made to process things and shape it into something we can recognize. We see faces in wood paneling. We see rabbits in clouds. And we can hear voices in static. Some people might hear something at the time, but find out later on it wasn't recorded on their recorder.. so they'd label it as paranormal because they heard it but the recorder didn't. But this is flawed thinking. Your brain may have heard it because it processed the sound of the area around you and turned it into something you could recognize, while the recorder just recorded what was there. Also, some recorders will record things that we may not hear, but this is because they can be more sensitive then our ears are. I don't mean that they are recording in frequencies that we can't hear, but just that it's amplifying the frequencies it is recording. You may not hear the soft wind blowing outside, but your recorder may be sensitive enough to pick it up. Some recorders also have switches to adjust the sensitivity of it. So just because the recorder picked up something that you didn't hear at the time, doesn't necessary make it paranormal.
Then sometimes one person will hear something, but the other won't. Some use this to claim that it's paranormal, because only some people heard it. If it wasn't paranormal, everyone would of heard it, right? Using the information above, you can see this may not be true. Everyone filters out noises at different rates. Just because you heard it and someone else didn't, doesn't make it paranormal.
Electromagnetic / Radio Interference
Then there's things like electro magnetic fields, radio waves, etc. that your recorders could pick up. If you have a cell phone, you may have noticed that right before it rings (or anytime it's on, really), nearby speakers may emit a sound. It won't pick up the conversation, but it may still hear noises (the phone connecting to the tower/network) that could be confused with something paranormal ("it wasn't heard at the time, so it may be paranormal", etc). Lots of other electrical devices can cause electromagnetic interference as well. And although most modern equipment is designed to try to eliminate this from happening, it's still possible it can happen.
Another popular idea is that recorders are picking up radio stations, and the voice we get is that. Although it's possible and can happen, I find it unlikely for most cases. Most radio stations play music, and the ones that don't, it would be unlikely that what would be captured would be relevant to what was going on in the location. Meaning, some cases involve the EVP answering people's questions, or making comments relating to what's going on at the time. It's possible, but the chances are more in favor of it not being relevant. Picking up radio signals can happen though, and should still be kept in mind. Wireless audio recorders can be prone to picking these signals up, and probably should be avoided in most cases.
So basically, I'm saying that it's possible for:
- Some people in an area, and not others, to hear a sound.
- Sounds to be heard by investigators but not recorded.
- Sounds to be recorded but not heard by investigators.
Any of the above can happen through non-paranormal means.
Frequencies
Speaking of recording something but not hearing it at the time though, one idea on this to explain it paranormally is that ghosts talk in a frequency that we can't hear (human hearing is between 20Hz-20kHz), but our recorders can pick it up. Then on playback, we're able to hear it. It's a nice idea, and may make sense to some people. But it's flawed.
For the above to be true, an audio recorder must record something at one range of frequencies, then play back the recording at another range (one we can hear). Basically, altering the audio. If this happened, this in itself would be enough to throw the evidence out the window for most people. It'd be like taking a photo and having the result run through photoshop before it was produced and presented to you. Most people wouldn't deem this as evidence, since it's was edited from what was really there.
There are ways to change the frequency of sounds, called frequency shifting. But this again edits the audio. And the end results aren't the best and would probably be thrown out by most people. Think of listening to audio on a recorder when the batteries are dying. That's what most may sound like.
But besides all that, what kills this idea (hearing the frequency of ghost talk only on recorders) is that the basic recorder most people use, it doesn't change the frequency it records. What it records is what is played back. And what it does record is a limited range of frequencies. Audio recorders are meant to record audio, usually voice (hence why most are called voice recorders). So they (the mic) are built to only record a certain range of frequencies. This is called the frequency response. They record what they hear (in the range they're built to hear at), and plays back that recording at the same frequency. So saying it records a frequency we can't hear, then plays it back at one we can hear, is flawed.
This isn't the best example, since I'm not using a high end voice recorder, I'm just using a cell phone, but the point I'm getting across will still be the same. My cell phone has a voice recorder on it. I can record something, then play it back. So I decided to test this out. I have a device that plays a tone at 12kHz (12,000Hz). Human hearing is between 20Hz and 20,000Hz, so I can easily hear it (it's an annoying tone! hehe). But when I tried to record it onto my phone, the playback recorded nothing. I also played the sound for someone else who I called and was on the other end of the phone, and they didn't hear it at all. I decided to test it out more, and generate tones on my computer and record them on the phone. It wasn't until I got to around 3,500Hz that I could finally hear it on my phone. So the frequency response of your audio recorder/mic will limit what can be recorded. What's the frequency response of your recorder?
Some take the idea of recording frequencies and determine that, if an EVP is below or above the frequency that we can speak (human voice is around 300Hz-2kHz), it must be paranormal. Since no human could of reached that frequency, it's not a person in the room, etc. Is this possible? Sure. We're not saying the recorder recorded something beyond our hearing range. We're saying it recorded something beyond our vocal range. So if you were to capture a voice at a range that we can't speak, but that we can still hear, that would be interesting. Of course, I'm not talking about some static type sound that you think sounds like a voice. I mean a clear, actual voice that is recorded beyond our vocal frequency range.
Some people may wonder, if we can't hear some frequencies, then of what use are they to us? There's infrasound (low frequency) and ultrasound (high frequency). We can't hear these frequencies, but they're still useful to us. For infrasound, this frequency range is utilized by seismographs for monitoring earthquakes. Bass is also low frequency, which is why we can feel it in music and such. And most people are familiar with ultrasounds. This frequency is used to penetrate a medium and measure the reflection signature or supply focused energy. Which produces the images of a baby inside the womb we see on the screen.
So although we can't hear these frequencies, we can still use them to feel and see things. If paranormal activity does/can happen in a frequency we can't hear, the next best thing would be to bring in equipment that can "hear" it, and will display it in a form we can use. Some researchers do try this by bringing in seismographs and other equipment, and some come up with some interesting results. Although it's not audio, it's still another form of trying to capture data. To do this though you must educate yourself on all the things that can cause the frequency you're recording so you can rule out things.
Frequencies and How They Effect Us
There have also been studies on how these frequencies we can't hear, can effect the human body. Long exposure to infrasound is known to cause awe or fear in humans. Some film soundtracks even use this sound we can't hear, to make people feel a certain mood at the right point in a movie. Some believe this may be the cause of some haunting feelings people have. The same idea goes for prolonged exposure to electro magnetic fields, some say they cause feelings of fear, nausea, feeling like someone else is in the room with you, etc. But I've not seen a study that without a doubt concludes this though. I'm more inclined to believe that sound frequencies cause these feelings then EMF's. That's just my thoughts though. But I'm open to all ideas. As for ultrasound, it is also being studied for how it effects us. Some studies (like one from Yale University a couple years back) say that prolonged (30 minutes or more) exposure to ultrasound may harm the development of a baby. Tested on mice, it was found that in those exposed, some nerve cells did not make their way to the correct parts of the developing brain. But studies are still being done.
Auto Gain Circuit
Some recorders (and video cameras) come with a setting called an auto gain circuit. Usually it's a setting built inside the recorder that you can't turn on or off. It's always on. But there are some models that you can manually set. Basically, this setting tries to keep all sounds recorded at a certain level of volume. If the sounds are very low, the recording volume increases, if the sounds are loud, the recording volume decreases. This can make it hard to judge the true volume of sounds in the recording since there's no steady volume it's recording at. But at the same time, when asking questions, it would amplify the area in between questions when you pause, which may help pick up something. But what if there is an EVP while you're talking, or directly after (when it hasn't changed from low to high amplification)? Your EVP would end up being lower in volume then if it had been if auto gain circuit was turned off. So it has some good and bad points. Most people try to get recorders without auto gain circuit though.
Also, some people use audio amplifiers. These are usually headphones with an amplification system that raises the sound level of whatever direction it's pointing at. It lets them hear what they normally couldn't. And this is true. But some people get confused when using them on investigations though, thinking it's letting them hear frequencies they normally couldn't (for example: hearing what a dog can hear but we can't). This isn't the case. All it's doing is raising the sound level of the frequency we can already hear.
Basically, in all the information above, I'm trying to give some more insight into frequencies and what you record. Some of the ideas people come up with on the subject are just full of holes. And there's more to it then just recording something and listening for a sound. Lots of behind the scenes work is being done. Both in your brain, and with the audio frequencies and recorder itself.
Audio Editing
Another popular practice in the paranormal field is to edit your audio to enhance it/better hear the EVP. You cut out the background noise, etc. But most of the time, this can do more harm then good. The background noise can be just as much a part of the EVP as the voice itself. By eliminating it to enhance the voice, you could damage the voice, or even create new sounds. Plus, hearing background noise may help you identify natural causes for the sound. If you edit it out and present that as evidence, you're basically helping eliminate listeners from preforming their own conclusions. You're editing your evidence to suit certain wants (wanting people to hear the EVP, not the background noise). Even if you don't mean to, and had the best intentions, that's still what it comes down to. And no credible investigator wants to be thought of as a person who edits their evidence to suit certain needs, do you? You want to present it as is.
When you filter out the background noise, you're deleting frequencies. And human voice, when talking, spans across a range of frequencies. So by eliminating some frequencies (like that of background noise), you could be deleting important parts of the voice/words. Think of if you get a recording of a person saying "Bus". The "B"and "U" sound may stand out when filtering out the background noise, but the "S" sound may blend in with the frequency of the background noise. So editing that frequency will kill the sound of the S. And you're left with something that isn't what was recorded. You may only hear "Bu" and be like "What does that mean?". If the voice is a clear voice, then enhancing may help some. But I wouldn't over-do it, because like I showed with the "Bus" example, you don't wanna delete key parts of an EVP. And if you do decide to mess around with enhancing, always keep the original recording. My take is, if you can't hear the voice very well to begin with, and if you have to enhance it to hear it well, then it's not a very good EVP to begin with. It's best just not to enhance it at all though.
But even if you don't edit your EVP's, you still may be subject to filtering the audio without even knowing it. Learn your recorders frequency response. This is the frequency it's able to record at. There may also be quality settings on your recorder. Lower quality means a lower frequency responses (low quality = less frequencies recorded = less file size if using digital recorders). It's like a digital image. Most digital cameras have quality settings. Lower quality produces a smaller file size, but that's because less data is written to the file.
Compressed File Formats
To create small file sizes, some people convert their audio to a compressed format, like MP3, WMA, etc. There's different ways to compress audio, but some go by taking out sounds that we wouldn't normally notice. For just voice recordings (which are limited in frequencies), this is usually okay and you wouldn't notice any difference. But for music and audio with background sounds, compressing could harm it. Those sounds have more frequencies then just voice, so taking areas out can be easily noticeable. If you've ever saved highly compressed song, you'll hear this. It sounds worse and worse the more you compress it. With audio containing background noise, the same applies. Many frequencies can be a part of background noise, so compressing it can alter what you hear. Sometimes in ways that may make you think you hear voices or other weird sounds in the audio. But really, it's just a low compression quality you're hearing causing sound artifacts. Basically, when compressing audio, the sound stored is not identical to the sound recorded. Try to keep your recordings in a non-compressed format, like WAV. If you can't do this, then just keep in mind that what you're hearing may have been compressed (altered) some and isn't identical to what was recorded.
Examples of Audio Editing
I mentioned that by enhancing your audio in an editing program (editing the frequencies), you can also create what some may think sound like voices. Some people wonder how deleting something (frequencies) can create something. Here's an example.
Listen to this audio clip.
Sounds like a typical EVP, right? Not a very good one.. but maybe someone whispering softly some words? Can you make out what they're saying?
Now listen to this file. It's the same as the one above, but unedited. Can you tell what it is now? Most would be able to tell it's a piece of paper being crumpled up. By editing (enhancing) it, it removed the crucial sounds that help us identify what it really is, and all we're left with are frequencies that, when our brain tries to figure them out, may sound like a voice.
Another example, listen to this file. Sounds like maybe someone talking/whispering again. Like a typical "cleaned up" EVP you may find online. It's been edited (enhanced) to clean out the background noise. Now listen to this version. Same audio, but it's the original, unedited, so it has more frequencies intact. Can you tell what it is now? Sounds more like glasses being moved around.
Now, I know. I did it backwards on you. We don't listen to enhanced versions then listen to the originals. We first listen to the originals then enhance anything weird that's heard. So if you had recorded these sounds, you would of heard the paper and dismissed it before even trying to enhance it probably. But you see what I'm getting at, right? Even if it's something you may think is a voice, enhancing it may eliminate crucial frequencies, and leave you with something that doesn't sound like the original, and that may trick your mind into hearing something that isn't there. Or what if your recorder was set (or made) to record low quality / a limited range of frequencies? The unedited product you'd get may sound more like the edited versions above then the unedited ones, and you'd think you might have something.. but really, you just have a loss of frequency/quality, so you can't easily make out what it really is.
Multiple Enhancements
Some people who do enhance things, do it once, And say "Hey, that sounds pretty good!", so they decide to enhance it again. And maybe again. Their thought is, the more enhancing, "the better I can hear it". But this is bad thinking. The more enhancing you do, the more frequencies you're taking away from the recording (the more quality you're taking away).
Here's an example:
Listen to this file. It's very clear, and most will have no problem trying to tell what it's saying. "This is a message". Although it is "enhanced" some, you can still make it out.
Now compare it with this file. It's the same recording, but enhanced more. We've lost some quality to it. Notice in the first one, how you can hear the "s" at the end of "This". But in this one, the enhancement edited it out. That frequency range it's in was deleted. Some may hear it saying "Disc" isn't of "This" now, when in the other one, it's clear that it's "this".
This is an example of how enhancing can do more harm then good. Especially multiple enhancements. Some people may also enhance their audio and notice the change, and think it's paranormal (what my EVP was saying changed right while I was editing it! spooky!). But this is just a lack of understanding what they're doing. They themselves are creating the different sound to the audio.
Also, like I mentioned, make sure you're using a decent recorder and that it's not set to record low quality (if it has that setting). Think of if you're recorder was set to/recorded a low quality recording, and you picked up the "This is a message" recording. Because of your poor recording, the message would be somewhat hard to understand, versus the high quality one which is more clear.
Now, I'm not saying not to enhance your stuff. Sometimes, if you know what you're doing, understand frequencies and understand what you are and are not eliminating, it can be useful. But for the everyday person, who is just looking to help clarify their recording, it's probably best just to leave it un-enhanced. If you can't hear it well to begin with, it's not a very good EVP then, and enhancing it will probably just do more harm then good to it. You don't want to be left with software artifacts rather then good data.
I'm also not saying you shouldn't record in certain frequencies. There's no 'set in stone' frequency that EVP's are recorded at, so test anything and everything. If you record in low quality frequencies though (narrow frequency responses), I'm just informing you that data may be lost if the EVP exceeds those frequencies you're recording at.
End
I didn't touch on everything I could have (there's alot!) but hopefully this article gave you a bit more knowledge of audio work, frequencies and editing. There's a lot more then just recording some audio and listening for anything odd. The more you know on a subject, the better you can critique it. And the better effort you can put forth at getting something truly unexplained.
----------------------------------------
The audio files for the "audio editing" examples were provided by the Association for the Scientific Study of Anomalous Phenomena". Visit their website, it's a great resource.
|
|
![[info]](http://p-stat.livejournal.com/img/userinfo.gif){kind=small}
matt_ferrell's journal
