"If you're lucky, you get audio and that is like what the plaster casts of footprints are to Bigfoot, some of the only "tangible" evidence we gather."
Getting EVPs is very rewarding and also not all that easy. In an ideal setting, you cover yourself as best as possible like our Sound Man. If he gets an EVP, I get chills. Why? Because of his methods. He is not an "everything is a ghost!" kind of guy, nor would he put out a Class C and say it's a ghost. He also is willing to put down almost 2 dozen recorders to cover a site.
Let's review the common classifications:
Class A: Obviously language, and everyone who hears it, hears the same thing without being prompted.
Class B: People might hear differing things, but it does sound like language.
Class C: Noises, not necessarily language.
Some do's and don'ts:
Do not do an EVP session holding the recorder or holding the recorder while walking around. Set the recorder down, preferably with enough distance that stomach growls will not be heard, but if your stomach does growl, please "tag" or announce it on the recording "Disregard, that was a stomach growl" or "Disregard, coughing."
Always announce when entering and exiting a room because ideally recorders are set up in the rooms. Believe it or not, often a question asked is answered in another room. Do discern if footsteps were you or something other worldly, it's best to say "Nancy entering room with John." and "Nancy exiting room with John." The person who reviews audio very much appreciates knowing who was shuffling about in a room.
Keep notes about the ambient sound of the building. "This building faced a noisy road and the front parlor and kitchen faced the noise." This way, when listening to recordings from those rooms, one can figure out the roaring in the background. "Air conditioner was in the upstairs hall, turning on and off during the evening."
A controlled EVP session is a great thing to have, gathering every investigator into one room to sit down and call out questions 15-20 seconds apart and tagging any shuffling noises amongst them. This way, should things be recorded in other rooms, everyone is present and accounted for.
The problem with many investigations is too many people wandering ad lib anywhere they desire. Try and leave the team outside and away from the building so their voices aren't caught and let a team of 2 walk the building and ask questions while tagging their entrance and exit from the rooms. Later, when listening to the recordings, all bodies are accounted for.
Do be sure to sync up the time on all the recorders. In an ideal situation, more than one recorder in a room is best. Use masking tape with a number on them attached to each recorder, draw a map of the building and put a number on the map where each recorder sat.
I like to use Audacity sound program and it's free online. It shows you the sound waves so you can see where a voice shows up. I only use speed and pitch at times to help discern something better. Slowing it down a bit and bringing down the pitch can make it very clear. Any more effects and you tend to get things that don't even resemble the original wording, so be careful. This program is also great because you can highlight the area you want to hear in a loop.
Here's the facts about ghost hunting: your chances of capturing visual are almost nil. The majority of what you find will be anecdotal testimony of what happened to investigators. If you're lucky, you get audio and that is like what the plaster casts of footprints are to Bigfoot, some of the only "tangible" evidence we gather. Take care and concern using recorders. They are your friend/they are your enemy. If you tag well, place them well, use lots of them on site, you up your chances of "proof" of haunting, but if you do a piss poor job, it'll be a nightmare to know if it's genuine or sounds unaccounted for.
Our sound guy also uses a very smart approach; if a voice/sound shows up on more than one recorder in the room, it's a sound in the room and if it's on only one recorder in the room, it's the genuine thing. Remember, EVPs are different than regular speaking. When I speak in a room, the sound waves carry and all devices catch it. A "spirit" voice; however, does not use sound waves, but records directly onto the device. How this is done is still a mystery and one of many, but knowing they are capable of this, gives us yet another avenue to backtrack a spirit and discern what it can and cannot affect.