What is a Spectrogram?
A Spectrogram lets you “see” a bird’s song! Most ordinary sounds are complex combinations of individual frequency components or harmonics with a wide range of frequency and intensity. A spectrogram is simply a power spectrum plot of the frequency components of such an audio signal as a function of time.
This program uses the Raven Lite program by the Cornell Lab of Ornithology to display bird sounds.
To see a bird’s spectrogram, click the word spectrogram in the Sound recordings section.
If the word “spectrogram” does not appear you will need to do two things:
1. Install Raven Lite from the Thayer DVD disk: Insert the DVD into the computer’s DVD drive. Then click the “My Computer” icon on your desktop, left-click on Explore and find the Drive with the Thayer DVD (probably the D drive). Double Click on this and then double-click on the file called RavenLite10_thayer.exe – this will then launch the program to install Raven Lite.
2. In the birding program, in Windows, click Tools in the Menu Bar, click Options, and then click Spectrogram. In Mac, click eViewer, click preferences and then click Spectrogram. The box should show “C:\Progran Files\Raven Lite 1.0 in Windows and /Applications/Raven Lite 1.0/RavenLite.app in Mac. If the box is empty, click the browse button with the three dots. Now search your hard drive for the Raven program. It is probably on the C drive under Program Files. Select the Raven Lite file and click OK. The word Spectrogram should now appear as shown in the image above.
This is what the spectrogram looks like:
Click the small triangle in the bottom row (center) to hear the song. Click Help to learn about all the other buttons. This is a separate feature on the DVD and is included in the Thayer birding DVD courtesy of the Cornell Lab of Ornithology. Please contact Cornell, not Thayer, with any questions or comments about the Spectrogram.
The button used to play a bird song will be grayed out until you select a song.
If a spectrogram does not appear, click File | Open Sound Files and then select a sound file.
If you installed the entire including the Media, the sound files should be located at C:\Program files\Thayer Birding Software\ eViewer 4\ Media \ sounds as shown below. Each sound file now includes the common name of the bird. For example “Abert’s Towhee_SO1.mp3
If you did a partial install and you need the DVD in the DVD drive to run the program, the sound files are located on the DVD itself at D:\Program Files\Thayer Birding Software\eViewer 4\ Media\ sounds. So just keep clicking on the folder icons until you get to the full list of songs. [If your DVD is not in the D drive, substitute the correct letter in the path shown above.]
For Help with the Spectrogram, please click Help on the Raven Lite 1.0 menu bar at the top of the screen, as shown below:
You may run Raven Lite as a separate program. Additional nature sounds are available from the Cornell Lab of Ornithology. Please check the Cornell Lab web site for updates to Raven Lite.
Using the Spectrogram
The Spectrogram user interface is a bit overwhelming. Here are some suggestions for first-time users:
1. Click View | Toolbars and uncheck all boxes but Play. Later you can check all boxes.
2. Put your mouse over each of the buttons to see what they do. With a song open, click on all the buttons, just to see what happens.
3. The Play button is the triangle in the middle of the bottom row.
4. Set the auto-contrast slider to 85-90 in order to better see the sound pattern in the bottom window. Using grayscale instead of color also helps.
5. Change the rate from 1 to .5 (slow down the song) or 2 (speed up the song)
6. Use the Zoom in buttons for a closer look.
7. Use a microphone and record your own voice – then look at it using the Spectrogram.
For More Sound Analysis Software
The Cornell Lab of Ornithology, in Ithaca, New York, is home to both the Bioacoustics Research Program and the Macaulay Library. The Bioacoustics Research Program offers programs called Raven and Canary that can be used by professionals and amateurs to visualize and analyze sounds. The Macaulay Library is the world’s largest archive of animal sounds and associated video. You can browse the archive online and listen to and visualize the sounds at Animal Behavior Archive
Raven Lite has its own help file, technical support and User’s Forums. Please contact the Cornell Lab of Ornithology with any questions about the Spectrogram.
Note: Previous versions of this software used a Spectrogram program created by Richard Horne. You may purchase his most recent version for $49.95 at www.visualizationsoftware.com