All sound file must be in OGG format

They can be converted to OGG using sound converter software of an online converter

The following should be used at your own risk. I accept no responsiblity for the suitability of these links or for any losses or damage incurred by their use

Some online converters:
http://www.online-convert.com/
http://www.mediaconverter.org/

Some free software:
http://download.cnet.com/Free-MP3-WMA-OGG-Converter/3000-2140_4-10793572.html
http://www.koyotesoft.com/
http://www.nch.com.au/switch/index.html
http://www.freac.org/index.php
http://www.freemp3wmaconverter.com/