Spectrogram ITC setup Tutorial
by Keith Clark
(Requirements: Windows 2000/XP/Vista operating system & sound card)
Step 1: Download the Spectrogram 15 full version or trial software from the html link in the article.
Step 2: Install the software.
Step 3: Where do you want to monitor the input sound from? If you want to monitor from your microphone input on the sound card of the same computer that you are using to view the real-time display, then make sure your microphone is on, connected, and enabled to record from microphone input in Windows. See the following picture:
Step 4: Open Spectrogram 15, go to “Preferences…….analysis controls……manual controls.” This setting will allow you to fine tune your settings rather than using the defaults.
Step 5: Go to “Function……..Scan Input”
Step 6: In this first example, I’ll show you how to choose the settings to monitor your recording input at full screen for the frequency range of 0Hz to 8Khz with 18ms averaging. Please use the following settings that you see on this picture:
What Do These Settings Mean To Me?
Sample Characteristics:
Rate: 22Khz – the frequency range you want to view & the capability of your sound card. 22khz will be sufficient.
Type: Mono or Stereo – Do you want to view one graph of one channel or two–one of each channel simultaneously?
Resolution: 16 or 24 bits? As far as resolution goes, the higher the better. Please choose 24 bits.
Display Characteristics:
Channels: Choose left channel, right channel, or both. If you choose mono, you don’t have these options.
Display: Choose either Scroll 1 or Scroll 2. Scroll 2 shows the audio graph at the top, Scroll 1 doesn’t.
Plot Type: Automatically selected for you as “Signal.”
Averaging: Averaging has the effect of “softening” the pictures – similar to the way a photo editing program does. It averages some of the audio data that is fed into it, resulting in a picture that is not too sharp. Typical averaging settings should range from 0 – 25ms (milliseconds). Any more than that and all you end up with is a blurry picture….and blurry ITC pictures will never be taken seriously.
Spectrum Level: This basically adjusts the volume level of the recording input that the software will respond to.
Palette: Here is where you choose a color range of blue to white, black & white, or a range that you create and define. I prefer “CB” – the blue spectrum range.
Frequency Analysis:
Frequency Scale: Please choose “linear.”
FFT Size points: Please choose “1024.”
Frequency Resolution: Changing this setting will have an extreme effect on your graph. I have found that the range of 75-90 seems to provide the cleanest definition available in this software program.
High Band Limit: This is where you choose the top of the frequency spectrum that you want to monitor. In our case we chose 8000Hz, which is the same as 8Khz (8 kilohertz)
Low Band Limit: This is where you choose the bottom of the frequency spectrum that you want to monitor.
Scroll Display Width: This is where you choose how fast you want the graph to go by from right to left. We know that spirit communication using sound takes place in extremely short periods of time. For ITC it would be best to stay within 4(the minimum screen display width) to 10 seconds. Think of it in this way – if you change your scroll display width to a full minute, then what you are assuming is that spirit is able to send you a picture and stretch it out over a full minute – something we know is not likely to happen! Think of the typical length of an evp.
*******You will notice I didn’t comment on all of the settings. This is because I do not have the answer, and do not want to give a wrong explanation. I’m not a technical audio person, and have represented the above descriptions to the best of my ability. The intention is to assist those who need help setting up the basic software to begin their ITC experimentation.********
Step 7: Hit “OK” and begin monitoring your recording input.
How to Duplicate My Experiments
In my experiments I prefer a screen resolution of 1024 x 768. Knowing that it may be difficult for spirit to send a picture within a specific time frame, I choose to monitor 2 windows simultaneously – one for a 4 second display and one for a 10 second display. Spectrogram allows you to run more than one instance of the program at the same time. I have also had better results focusing on a specific frequency range – my preference is 2Khz to 4Khz. Here’s how to imitate those settings:
Hit O.K., and the program will start monitoring. Since we are only viewing 2 – 4Khz, you will need to make the program window smaller to fit either the top or bottom half of your screen – Otherwise your picture will be horrible because your frequency range is now stretched to fit the full screen, and that is disproportionate. After you make the window smaller, go ahead and minimize the window. Your window should look like this (If you have a live audio input feed)
Open another instance of Spectrogram for our second display window, and choose the following options:
Notice that I changed the display width to cover a longer period of time and the averaging to 25sec. In the display, you will see that this second window will appear almost exactly the same as the first window – except for the fact that one will be scrolling faster than the other. Your second window should look like this:
Now you can make each window half the height of your 1024 x 768 screen and view both of them at the same time.
Here’s how it looks on my screen at this particular moment:
Tips, Tricks, & Troubleshooting
1. Use the space bar to start and stop the monitoring of the graph. The first time you open the program you must manually go to “Function….scan input…..O.K.”, but afterwards you can simply start and stop the graph by hitting the space key. You can continue to hit the space key if that is the method you used to stop the program.
****Special tip**** It took me a long time to figure this one out! If you click on the top of the graph display before you hit the space bar, you will notice that the program stops the feed, and then re-represents the entire display again from left to right – and most likely it will change completely! This is for people that want to change the settings of the display that is currently in the window. Most of you will not want to do this. How to get around it? Very simple. Just click on the bottom of the graphical window where the textual information is displayed before you hit the space bar. Now you can view it live, and when you hit the space bar it will stop exactly where you want it to – without re-representing the data. Hit the space bar again, and it will start monitoring live.
2. “I don’t see anything appear on my graph!” or “Everything is a solid white color!” - You will need to manually adjust your input volume for recording and/or the volume level that Spectrogram will adjust to. I recommend you do the following:
Adjust the recording volume in Windows to about 50%. If necessary, you can also raise or lower it, but we can also tell the software which volume range to monitor at. What we don’t want is a signal that is too low or over-amplified, resulting in clipping and distortion. After your Windows volume is satisfactory, here’s what you need to change in the software:
Change the min and max volume level until your graph display is satisfactory. For example, instead of “0dbmax” and “-80db min”, you could change it to 10dbmax and -90dbmin (add 10 to both of them). There is not one magic setting for everyone, if simply adjusting your microphone input in Windows doesn’t do the trick – this is the place where you need to change it.
Comments by Keith
This tutorial is designed to assist ITC researchers with basic instructions on how to setup the software program Spectrogram 15 and use it as a tool to communicate with spirit. As far as I am aware, this is a new area of research, one that can branch out and has the potential to improve the experiences we have with ITC. As stated previously, I am not a person of extreme technical knowledge. If a person of technical knowledge does read this tutorial and has either something to add or a correction, please let me know.
What’s so special about this method? Well, first of all there will be some people who will be successful at this method – people who ordinarily would not have the opportunity to receive an image directly from spirit. Second of all, an assumption could be made that spectrogram results would most likely be the same as an individuals evp results. This is not true. I have never received what I consider to be successful and consistent evp recordings, yet I have received acceptable images with the audio from a musical instrument. This means that when it comes down to it, images through sound may overcome some of the boundaries encountered by evp. Yet at the same time, there will be limitations that are very close to recording of evp audio.
Spectrogram experiments still follow the same rules as other ITC experiment methodology. ITC experimentation is a personal relationship with spirit through which evidence is obtained using technical means. In order for an experimenter to achieve phenomenal results, they must achieve a close bond and understanding with those working with them from the other side. It is in this way that we have the opportunity to push forward, break the boundaries, and change the world for the better. As ITC experimenters, this is what we work towards.
*******(I have no affiliation with the company that produces the software mentioned in this tutorial.)*******
Comments are always welcome.
Keith Clark
ITC Bridge
keith@itcbridge.com
August 12th, 2007