Sonogram - An acoustic signal analyzer / editor
 
Version 0.90 beta
 
Description:
 
1: What does this program do? 
 
Sonogram allows you to analyze time-varying audio signals such 
as birdsong visually. It uses either FFT ( Fast Fourier Transform ) 
or Wigner-Ville transform to calculate instantaneous power 
spectrum and displays the results as a sonogram - a two-
dimentional ( time and frequency ) density plot of sound energy. 
Also, you can do time and frequency measurements by clicking 
and dragging the mouse inside the sonogram window, and display 
the power spectrum curve at the cursor point in real time. This 
program is in part based on EdSnd1.4 by James Pritchett and 
Steven Boker and inherits some signal editing capabilities of 
EdSnd.
 
2: What do I need to run this program?
 
You need two things: a NeXT computer and an input signal. As 
an input signal, you need a 16 bit-linear monaural NeXT format sound 
file. You need an external A/D converter to create 16bit linear 
sound files. There are several products such as DigitalEars, A/D 
64x and Digital Microphone that let you do this.
 
Another way is to convert an 8kHz CODEC sound file ( output of 
NeXT built-in A/D converter ) to 16bit linear format. For that 
purpose, I have included a couple of unix programs to convert 
sound files to 16bit linear monaural format. Please note that the 
converted signals still have only 0 - 4 kHz bandwidth. If the 
frequency of your signal is higher, you have to run the tape 
recorder in half or quarter speed when you digitize the sound 
with NeXT microphone input.
 
3: What is included in the package?
 
The package includes the executable program, documentations, 
several unix-utilities with source programs, and a couple of test 
signals. It does not come with source code (at least in this version).
 
4: Is this program free?
 
You can download and use this version (0.90) of Sonogram 
without charge, although the author reserves all rights to this 
program. You can redistribute the program freely, but you must 
do so free of charge except media and handling charges, and you
must keep all the included files intact.
 
Hiroshi Momose, author
Zoology, UC-Davis
Davis, CA 95616
 
hmomose@ucdavis.edu