This is a quick illustration of how to make sure that your WAV files are the correct format for SL using the free audio editor Audacity. I am assuming that you have downloaded Audacity from the web site and installed it. http://audacity.sourceforge.net/
1. Open the file that you wish to convert in the editor and click on the name of the track to open the track menu.
2. Check that the Sample Format is set to 16-Bit
3. Check that the bit rate is set to 44100Hz.
4. In the File Menu, choose Export as WAV