For those of you who are not familiar with command-line operations,
here is how to use the sox program *from Windows*. (Note: Mac users
have reported that they had to use the latest version: sox-14.4.1 to
get sox to work on a Mac.)

1. download the "sox12181" zip file from SourceForge. Unzip and extract the sox file to desktop.

2. In windows: click start-> All Programs -> Accessories -> Command Prompt.  
A commandline window should pop up.

3. In Command Prompt window, type: cd desktop

4. In Command Prompt window: (with the sound file you wish to convert on desktop as well), type

    sox secret.wav secret.dat 

5. Now you should see the converted file secret.dat on your desktop.