Analyzing Digital Audio

daOne of the most common methods we use to gather evidence in an investigation is audio. For the purposes of this article, I will focus on digital recorders. Since some readers may not be familiar with the use of digital recording, let’s go over the basics first.

There is such a wide array of recording devices available on the market today, that choosing one can be intimidating. There are inexpensive models you can purchase at any electronics store, some even have intelligent noise cut to remove much of the background noises for you as it records. I saw a wrist recorder online recently at quite the reasonable price. I have not tried it, and so will not speak to its quality. There are models that gather sound from a full 360 degree radius and allow in the field play back, which are more than double the cost. I have recently seen a 360 degree model coming out that has flashy visual features, with all the bells and whistles – I shudder to think what the cost will be when it hits the market. I have several recorders of differing types; some cost around $70 and my 360 cost $300.

To be honest, all of the models I have tried get great sound and have very sensitive microphones. That said, the fancier models have a learning curve. You will need to read up on them and practice prior to bringing to investigation, in order to use properly and get your money’s worth out of the features. If you are not a “read all of the instructions person”, these are probably not for you. My favorite is a $70 digital with intelligent noise cut that I purchased at a local electronics chain. Just be sure you get a model with a USB port (rookie mistake many, many years ago). The more advanced, expensive models can be purchased online from any of the paranormal equipment sites, or from Amazon, etc. to save money. After paying $300 for my 360 recorder online, I saw it a music store that caters to bands, etc. for $70 less than I paid. In short, shop around if you are looking for these models.

As stated above, I have several recorders, as do other team members. During an investigation, we ensure that they are spread throughout the room, and often will leave recorders in areas of reported activity even when we are elsewhere on site, to optimize opportunity to capture something interesting (just don’t forget to retrieve before you leave! Recorders should not be held on your hand, as you often see on television, as these sensitive microphones will pick up every time you inadvertently move your finger, or shift your stance. This will contaminate your evidence. They should be placed on sold flat surfaces during a session. Similarly movement should be kept to an absolute minimum, and any noises of which you are aware of the source should be ‘tagged” as such, so as not to be mistaken for potential evidence. Some use white noise in EVP sessions (white noise would sound like static from old model televisions, or a radio not tuned in to a station), [] believing that spirit will come through the noise to communicate. Others, myself included, take measures to eliminate any extraneous noise, believing this enhanced the ability to hear any potential finding more clearly.

My team places a few recorders around the room/area during each session, for a number of reasons. First, one recorder may be closer to a sound source, for example an air vent, which may then serve to debunk a less clear artifact that is farther away – as in furnace/duct work noises. The same can be said for a recorder near a window debunking voices as people outside. Second, more than one recorder picking up the same potential EVP (Electronic Voice Phenomenon, a response which, while not heard at the time of recording, is heard on recorder upon evidence analysis), this can serve to corroborate the finding. Third, at times a potential finding may be caught on one recorder, but not another, due to many recorders’ microphones being extremely directional – only picking up sounds to one area in relation to its placement. [1] With only one recorder, we would have missed that piece of potential evidence. Keep sessions relatively brief, and stop the recorder between rooms/areas so that they are easier to manage in analysis.

So now you have the very basics. Time for the subject at hand, analysis. You have conducted a controlled EVP session; what now? Some people choose to listen for EVPs with the naked ear. Others by simply plugging earphones into the recorder itself. Depending on your purposes, these personal choices may work fine. However, it is more difficult to discern what you are hearing and even more difficult to isolate the area or find it again later. In order to manage hours of recordings from an investigation, with the intent of presenting findings to a client, these methods would prove ineffective.

Many investigators choose to use analysis software installed to their computers. There are many to choose from in this category as well. Some can be downloaded for free, others offer a free trial period before you would need to purchase. Some are more user friendly than others, as in most software. As I do not wish to tout one software program over anther, my advice is to shop around, ask seasoned investigators for their opinions – and the reasons for those opinions.

If you choose to use analysis software, you will need to familiarize yourself with its capabilities. Keep in mind that these programs are also used by musicians, etc. to edit the sound of their music. You will not need many of the features. Using the USB connection that comes with your recorder, plug the small end into your recorder, and the USB into your computer. Open your analysis software program. Select one file to work with first. With your analysis program open, select a recorded file to work with first and open it in your program. I use noise-canceling headphones personally. Listen closely to the file. You may hear an anomalous sound or what seems to be speech. With the software, you have the ability to select that area to isolate it. I personally will then play it on a loop, so that I can begin to seek out a debunk for the sound…never neglect your due diligence! If the area continues to be of interest, I save it into a folder with site, room, and what I feel it may be, then come back to the clips I’ve saved at a later time for closer analysis. Once I have gone through each fie, I then go back and examine each saved clip more closely, listening for natural explanations and determining what I hear. I then delete debunked clips, and change the name of those I choose to keep (adding “.lisa” to the end of the clip name helps me keep track of where I am in the process and stay organized). Other investigators choose to resolve each anomaly before moving on. It is merely a matter of personal preference.

While some investigators alter their clips by amplifying, slowing or speeding up the clip, filtering, adding effects to them; others, myself included, feel that if it is necessary to manipulate it to that extent, it is not likely a viable piece of evidence. This level of manipulation also makes the clip sound mechanized and will likely be seen as suspect. While at times, some amplification may help to hear a clip better, potential evidence should be altered as little as possible, if at all. Personally, I use the software simply because it makes managing the copious amount of recordings more manageable with the ability to save areas of interest. Keep the whole files as well, in case you need to refer to them at a later date. Realizing this can eat up space on your hard drive, thumb drives or CDs for each investigation are life savers. I also make a copy of any findings that “make the cut” for my clients to keep for themselves.

“Background noise is important! It provides an audio context and reassures the listener that the recording has not been manipulated. It can also provide clues to any possible natural explanations for apparently paranormal sounds. For instance, is the paranormal sound louder than the ambient background noise, about the same level or fainter? If the sound is louder than the background noise then there is the possibility that it is a real sound that was not noted at the time or was forgotten. It is also possible that the microphone was directional and happened to be aimed at a sound source that no one noticed at the time. It could also be radio or electrical interference. If the apparently paranormal sound (APS) sound is at the same level as, or fainter than, the background ambient noise, then it could be a chance effect. Background noise is, typically, random and unpredictable. If two elements of it (such as a squeaky chair and a creaking floorboard or an electric fan and a noise from outside) happen to occur at the same time, they may combine to sound like something quite different and weird. By listening to the background over a long period, you may be able to deduce that this is precisely what has happened.” [ibid]

Now, you have thoroughly analyzed your digital audio recordings – quite a lengthy and daunting task with the hours of audio. You have done your due diligence to eliminate any and all natural explanations for the voices or other anomalies you found. You have carefully documented from where they were taken and on whose recorder (prior to starting a session in each new room, my team is sure to turn on our recorders at the same time, introduce the site, date, time, room, and who is sitting or standing where). Now you are meeting with your client to review what you feel has “cut the mustard”, so to speak. It is very easy to manipulate what others hear if you tell them u front what you feel the clip “says”. Personally, I give the client headphones and play the clip at least once to orient them to the actual length and sound of clip, being careful to avoid them seeing the “name” of the clip. If they wish, I will put it on a loop. I encourage their input as to what they hear. Only when they have had ample time to assess on their own, do I tell them what I feel I have heard. At times, what the client hears makes more sense to the context of the site and their experiences. Remember to stay objective and open-minded. Find a process with which you are comfortable and off you go!

Lisa Shaner-Hilty

Lisa Shaner-Hilty

I am a supervisor for several programs assisting individuals with intellectual and mental challenges. I have 2 Masters Degrees from Penn State in Communication Disorders and Psychology. My first experiences with the paranormal were around age 5. I’ve been fascinated ever since. I have been an investigator for over 10 years (first 5 years with a team, then leaving to form my own more than 5 years ago, and have taught classes on investigation, evidence analysis (especially EVP) and debunking at local community college. I also have abilities, some of which began at age 5 and others around puberty. Therefore my fields of major interest are investigation and psychic and empath. While I am open to considering all aspect and viewpoints, I am dedicated to seeking natural explanations first before anything is considered evidence.
Lisa Shaner-Hilty

Latest posts by Lisa Shaner-Hilty (see all)