Hi,
Your Waveform has time and data information. You should unbundle it (Get Waveform Components) and use the data array as an input for the Snd Write Wave File.vi (Functions>Graphics&Sound>Sound>Sound File). The 'sound format' input refers to the sampling rate of your waveform, which will tipically be 8000,11025,22050,44100 Hz.
The file is in a PC wave file (.wav) format and can be read by the Snd Read Wave File VI or other applications.
A good example to look at is: Help>Examples>(Directory Structure)Sound>sndExample.llb>Simple Audio Player.vi. There you'll find everything: since how to store and play music, since how to code and decode wav files.
Regards,
Guillermo