The configured cwdaemon is neccesary to control rig ptt.
The voice_keyer.sh plays messages using mpg123 cli player  
You can install it using:
$ sudo apt-get install mpg123

The voice_keyer plays mp3 files which names are F1.mp3 - F10.mp3

The example file F10.mp3 is the 5s long 1khz tone for test and volume adjustment.