BTInterface is equipped with a selection of sound effects which can be played by sending a command sfx (and a number) over the bluetooth serial interface, or they can also be activated via incoming SMS text messages.
The command sfx should be followed by the number of the sound effect without any spaces so
And this can be upper/lower or mixed case. SfX1 sFx1 SFX1 etc.
You can check out the sound effects from within BTInterface as these are the same ones that you can play when you press the Menu key and choose Settings on the Sound Effects panel.