12 replies to this topic

[Arius]

I'm just curious about whether or not anyone has used any sort of audio amplification device. My group has something that we call the "Super Ear." It's a box with a microphone built in, and a headphone jack, with various levels of amplification.

We were doing an equipment test investigation at a nearby cemetery, one that we tend to get activity at on a regular basis (this makes it a good training/testing location) and my friend Viktor was using the Super Ear, and we also had a digital recorder going at the same time. At one point, Viktor heard something, like a voice speaking underwater (gurgling, sort of) and he mentions it (you can hear him on the recording saying "Did you guys hear that"), though none of the rest of us heard anything.

So, the next day we're going over the audio that we recorded, and low and behold, there is a gurgling voice, followed by Viktor saying "Did you guys hear that?" Basically, none of us heard anything with our ears, but both the recorder AND the Super Ear were able to "hear" this unusual sound. I should also note that the recorder's mic sensitivity was set to medium/low, so it should have only been picking up sounds from our immediate area, and nothing so far away as what the Super Ear was picking up.

Now, we use the Super Ear often (though Viktor went for a while without using, saying that the things he heard were just too creepy, lol) and we're looking into picking up a couple more, probably some that are a little higher end.

So, like I said at the beginning, I was just wondering if anyone else had heard of something like this being used, or used something like themselves.

AMdG

[CaveRat2]

While not a Super Ear type microphone, I use high gain amplification and stereo pickup at all EVP sessions. You do need to be aware that high gain amplification does allow you to hear distant sounds that otherwise might be missed, thus they can be a source of false positives. But with some care regarding placement and microphobne types, amplification done on the recording side is much prefered over fooling around after the recording has been made.

My system uses two cardioid electret microphones (non-inductive) feeding into a pre-amp with voice band emphasis. The out put of this unit goes to a set of headphones as well as a stereo cassette recorder. At times I will use inductive pickup sensors in place of the microphones since some EVP has been theorized to be electrivcal rather than audible. But either may produce EVP, so the jury is still out on that issue.

[afterlife]

I have heard of other groups using these kind of devices & they boast on being able to pick up sounds from 100 yards away. I think any EVP caught with this kind of device would be void because you cant say 100% that it originated from the location being Investigated, especially in an out door environment.

[CaveRat2]

afterlife, on Oct 7 2009, 12:18 AM, said:

I have heard of other groups using these kind of devices & they boast on being able to pick up sounds from 100 yards away. I think any EVP caught with this kind of device would be void because you cant say 100% that it originated from the location being Investigated, especially in an out door environment.

Actually you can determine that information but that is what I meant by requiring additional care. You can do this by recording ambience in the area you are monitoring. This is a sample recording which can later be used as a baseline to determine how the particular area in question "sounds" naturally. This can be compared on an oscilloscope to determine if a possible EVP exhibits the same characteristics. From that validity can be determined. Not something the average person has the equipment to do, however it can be done. Plus you need high quality (no digital voice recorders!) audio to work with, preferably recorded in stereo.

Another method if the source is audio is the use of spatial analysis. This involves timing the audio arriving at two microphones placed a known distance apart. Since sound travels at a known speed it becomes possible to calculate the direction from the mics where the sound originated since it arrives at each mic at a different time, milliseconds apart. The time difference represents the angle from the mics where it originated. Again stereo is required and high quality audio needed as well as a dual trace oscilloscope capable of displaying time lead / lag between the traces.

[Arius]

I whole-heartedly agree that typically any EVPs picked up by something with such a range should be thrown out, but--like I said--the possible EVP we got was picked up by the recorder itself, which did not have an amplified mic. What I was getting at was that whatever made the sound (paranormal or not) did so in a way that out ears were unable to hear it, but both of our electrical devices managed to pick it up.

AMdG

[afterlife]

Arius, on Oct 7 2009, 05:13 PM, said:

I whole-heartedly agree that typically any EVPs picked up by something with such a range should be thrown out, but--like I said--the possible EVP we got was picked up by the recorder itself, which did not have an amplified mic. What I was getting at was that whatever made the sound (paranormal or not) did so in a way that out ears were unable to hear it, but both of our electrical devices managed to pick it up.

AMdG

Its possible the sound wave you picked up was on a lower or higher frequency than what humans hear. Kinda like a dog whistle, Ive done experiments with DC frequencies which we cant hear with our ears but the recorder picked up just fine.

[OMPRDave]

Didn't you say one of the investigators heard it? IF that is the case it would be more of a disembodied voice rather than a true EVP.

I'm still on the lookout for a good preamp to use for my cassette recorder. I also got hold of a decent 4 track recorder that will layer all 4 channels at the same time so I can mike different points in the room to sort of map where any potential sounds are coming from in real time analysis. Think I will experiment with it a bit before I try amplifying any recordings with it.

[afterlife]

OMPRDave, on Oct 7 2009, 06:44 PM, said:

Didn't you say one of the investigators heard it? IF that is the case it would be more of a disembodied voice rather than a true EVP.

I'm still on the lookout for a good preamp to use for my cassette recorder. I also got hold of a decent 4 track recorder that will layer all 4 channels at the same time so I can mike different points in the room to sort of map where any potential sounds are coming from in real time analysis. Think I will experiment with it a bit before I try amplifying any recordings with it.

I think the Investigator heard it with headphones connected to the recorder.

[OMPRDave]

Gotcha...

[Arius]

Here's what happened:

None of us heard the sound with our ears.

Viktor (one of my investigators) had the Super Ear on, and he heard it through the headphones that were connected to the Super Ear.

When we went back to review evidence, we heard the sound on the recorder, right after Viktor mentions what he heard on the Super Ear.

AMdG

[OMPRDave]

Interesting...I used to talk with a guy who said he had great success at getting dialog recorded while going through a "miracle ear" type device into a recorder and out through headphones while his regular equipment would get nothing. Where the miracle ear doesn't work on the same principles, it is interesting to see some basic correlation.

[CaveRat2]

It would be possible for this scenario to develop if the source were some form of EM Field inducing a signal into the electronics. Both the amplifier in the high gain mic and the recorder would be susceptable. I can't say how well shielded either device is without actually seeing and testing them, but if this was a digital voice recorder these generally have poor shielding against EM Fields.

The super Ear, I can't say. All high gain amplifiers require very good shielding to prevent interference from outside sources. If this has that then we would have to look for something else. If shielding is poor, then it would be susceptable to the same fields as the recorder. Thus both devices could pick up on it. It is clear, since both devices picked up, that SOMETHING was there. Without knowing details on how well shielded the devices were I can't say what though.

OMPRDave, on Oct 7 2009, 06:44 PM, said:

Didn't you say one of the investigators heard it? IF that is the case it would be more of a disembodied voice rather than a true EVP.

I'm still on the lookout for a good preamp to use for my cassette recorder. I also got hold of a decent 4 track recorder that will layer all 4 channels at the same time so I can mike different points in the room to sort of map where any potential sounds are coming from in real time analysis. Think I will experiment with it a bit before I try amplifying any recordings with it.

Dave, what make / model 4 track did you get? Most only allow two track recording without modifications. (I modded a Tascam Ministudio to do 4 track simultaneous record). Just curious....

[OMPRDave]

I was wrong..it's a Korg CR4 (minus most of the knobs), but it's still operational.