Paranormal Research Techniques: Extracting Audio from Video Files

Imagine the scene: You're sitting quietly in a silent room, hours into a rather luckless investigation of a reportedly haunted building, when suddenly you hear footsteps on the floor above you; the floor currently unoccupied by living beings. Your heart pounds as you silently beseech every God you can remember, begging them for the audio to come through onto the video camera you hold in your hand. After the investigation wraps up for the night, you're so exhausted that you know the review will have to wait. The next day, you remember the events and rush to download the video from your camera, eagerly watching it, headphones pressed tightly to your ears. Moments tick by until...there! You can hear the far away sound of footsteps in the hall above. The sound is so faint, though, you're not certain anyone other than a bat might be able to hear it. What's a paranormal investigator supposed to do at this point? Exactly how does one perform that arcane magic which transforms the softest whisper into the startling 'enhanced audio'?

In the realm of paranormal research, evidence is key and audio is a cornerstone to that evidence. Listening to the enhanced audio clips from an investigation can turn a rather ho-hum presentation into a fantastic discovery that leaves everyone involved speechless. The problem is, many investigators aren't sure how to get from raw film footage to workable audio files. While we'll be the first to admit that the process of data review is tedious and time consuming (how long can YOU stare at a quiet, empty room before you fall asleep?), the process of extracting the audio from your video files is actually quite simple. With the help of this article, you'll be splitting audio from video in no time, and even performing a few basic enhancements (enhancements, not enchantments!) to that audio in no time!

Before you begin, you'll need to have some software installed on your computer. There is good news here: these programs are all free. For this tutorial, you'll need AoA Audio Extractor Basic, Audacity and the LAME MP3 Encoder. We've included the links for the software downloads in the resources section of this article, so if you don't already have them installed, take a few moments to do so now.

Ready for your step-by-step instructions? Look how easy this is!

Open AoA Audio Extractor.

1. Click on AoA Audio Extractor Basic.
2. Click on Add Files and browse to the folder where your video is stored.
3. Select your video and click Open.
4. Verify your output options.
   
   Tip: Extract to a Stereo MP3 with 128 kbps and an Audio SampleRate of 48000
   
5. Set your output path (this means to choose where you want the new audio file saved) by using the browse button.
6. Click on Start.
7. When the conversion is done, you will be given a confirmation notice; click OK.

AoA Audio Extractor will open the folder where it saved your new file so that you can verify the file is correct, and then you'll know you're done! Your audio is now separated from your video and you're ready to move on to Audacity. Close the folder and AoA Audio Extractor.

Wondering how this process could be so easy? Think there might be some trick we're not mentioning? We thought it might help if you could watch us do it first, so check out this video and you'll see it really is as simple as we've promised!

Now, we'll admit that this part is a bit more complicated than the first steps, but we're certain that you can do it. We're going to walk you through each step, and that means you'll need to have an MP3 file ready to work with- which you should have, if you've completed the first portion of this tutorial.

Tip: Whenever you see an arrow like this → it refers to a nested or 'child' menu. That means you'll have to click the first menu to find the second, the second to find the third and so on.

The first step is to open Audacity and File→Import→Audio. Browse for the MP3 file you'd like to work with and click open. Audacity will begin importing the file, a process which can take quite a bit of time, depending on the file size. Don't panic if it looks like Audacity has crashed; even if a message tells you it has stopped responding, just be patient. Its probably just still trying to work through the file import. Once its done, the file will open up and you'll be able to see it in Audacity's standard waveform view.

If you're like our team, you've already reviewed your audio long before you reach the stage when you're ready to isolate sections of it. This means that you probably won't need to play the file from beginning to end when you import it into Audacity. It also means you are most likely armed with exact time stamps for interesting sounds that you've noted in the file. To isolate those sounds, you're going to need to learn to zoom and trim the file.

Again, the zoom process can be slow, especially with large files. Zooming is done by going to View→Zoom In, or by the keyboard shortcut Ctrl+1. Once you've enlarged the clip, you may need to use the slider along the bottom to find the exact time you're looking for. You can also use the green play button at the top of your screen to verify that you've found the correct section.

After you've zoomed in on the audio section you'd like to isolate, you're going to want to trim away the remainder of the file. This means you'll have to create a selection of audio to save. Selecting audio is done by placing your cursor on a starting point, pressing down the mouse button and holding that button down as you drag the cursor to the end point of your choice. One of the most useful tips we can share with you is to tell you that Audacity isn't picky about which way you drag your mouse as you select your audio; you can go from the start of the audio file and move towards the end or, if you're feeling frisky, try it the other way around.

Once you have your section highlighted, a quick trim will eliminate the remaining audio, leaving you with exactly the section you chose. The trim tool is easy to use and can be found by going to Edit→Trim or by the keyboard shortcut Ctrl+T.

You'll quickly discover that the 'Zoom+Trim' process, when repeated a few times as you narrow down your audio, has become a staple to your data review process.

Now that you've learned how to isolate your audio, you're ready to try your hand at your first audio enhancement. For this tutorial, we're going to use the simple 'Amplify' tool included with Audacity.

Tip: While the Amplify tool can be very useful, all audio files will not react well to it. Many audio files will take multiple passes through several difference enhancement filters to bring them up to the level seen on many paranormal websites.

Audacity's Amplify tool is an easy way to change the volume of the audio you have selected. Since the file you're working on has already been isolated, odds are you'll want to Amplify the entire thing. This can be done by going to Edit→Select→All or by using the keyboard shortcut Ctrl+A. Remember, if you only want to enhance a portion of your file, you can use the same click-and-drag method you already learned to select the exact section you want to modify.

Once your selection has been made, you'll need to open the Amplify window. This is done by navigating to Effect→Amplify. You now have the ability to increase the volume as much as you'd like, but you have to remember that a sound file can become distorted quickly if you meddle too much. Its usually a safe bet to check the box next to "Don't allow clipping"; this means that the program will not allow you to amplify the sound so much that the audio ends up beyond the range of the waveform.

To make this process easier to understand, we've included a video which shows each step of the way. Take a few moments to watch it now- you won't regret it!

Once you're comfortable working with the basics, there is a whole world of audio software out there for you to discover. You can start by learning more about the other effects included in Audacity, and after that, well, you have the entire internet at your disposal! It's full of fantastic software designed to help make the mystifying process of audio enhancement as easy as, well, clicking your mouse.