Spectrogram Software
Each DolphinEAR comes with a free software to produce your own
SPECTROGRAMS. It allows you to 'see' underwater sounds and analyze their
content. It's a great program written by Richard Horne and generously made
available to us for inclusion with DolphinEAR. It produces graphicssimilar
to the type of 'waterfall displays' used by SONAR operators on U.S. Navy
Nuclear Submarines to detect and indentify underwater sounds.
WHAT'S A SPECTROGRAM?
'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 plot of the frequency components of such an audio
signal as a function of time. In this Spectrogram program, digital audio
recordings (.WAV format) are analyzed to produce a plot of frequency versus
time, with harmonic intensity represented by a variable color scale. These
spectrograms reveal the fascinating hidden frequency structure of audio
signals and can be used for identifying or classifying particular sounds.'
Look at the samples in our 'SOUND SAMPLES' section
- all of which were processed with this software! Frequency resolution
is typically 20 hz or less! Placing the crosshair cursor over any point
on the spectrogram shows time, frequency, and level data in a special 'data'
window. If desired, you can also save your spectrogram sample as a set
of data points for analysis by other programs.
REAL TIME DISPLAYS
The software allows you to display underwater sounds in real time,
or from previously recorded tapes. You can also record 'digital recordings'
of underwater sounds and save them on your computer hard disk. These features
provide many possibilities. It is not necessary to carry your computer
into the hostile marine environment to see carry on spectrographic analysis.
You can record sounds on a simple ausio cassette recorder, DAT, Camcorder
or other sound recorder, then play the tape back into the computer for
analysis at a later time. See our 'RECORDINGS' page
for futher details.You can also watch realtime display indefinitely and
start a digital recording when something of interest is heard.
REQUIREMENTS:
- OPERATING SYSTEM: Windows 95/98, or Windows NT 4.0.
- RAM: 16MB or more
recommended. Runs in limited form with 8 MB RAM.
- DISPLAY: 256 colors
recommended.
- SOUND CARD: Windows
compatible sound card, or equivalent, to record and play back sounds. Not
necessary to analyze computer files in .WAV format.