You will find sample command at the command line on this page.
$mkdir vox
$cp vox.tar.gz vox
$cd vox
$tar -zxvf vox.tar.gz
$make
$./vox
$./vox -r yourbigspeechfile.wav youremailid@somehost.somedomain
$./vox -e yourmessage.wav codedfile.bin youremailid@somehost.somedomain
$./vox -d codedfile.bin outputmessage.wav
Graphical interface's screenshots are shown below: