The widget library supports a simple method in playing sounds on presses.
uiClickSound = snd_yoursound;
If you set this on your widget then it will automatically play the sound for the widget.
If you need more control over the sound played then you can use a callback script that you customize. Your callback script will get executed when the widget needs to play a sound. To set your callback script:
Your custom script needs to have only one argument. That argument can be:
1 : on left pressed //when pressed
2 : on Move Start; //only callback future
3 : on Move End; //only callback future
4 : scrolling //only callback future