Hi Reece,
This is an area that I have tinkered around and made a few mods myself. You can find my sound mods on the link below. Ok now that I've had my sales pitch, this is what I use as my program "Jetaudio", it's a freeware product with no strings attached. It converts sound files including OOG's. This is the link;
http://www.cowonamerica.com/download/
Ok now these are some sites that I use to merge sounds into the speech files etc, these are the links;
http://www.cowonamerica.com/download/
http://freesound.iua.upf.edu/index.php
Ok the steps that I use is simple, if you want to incorperate additional sounds into a speech file (OOG) then you convert it back to a MP3 using Jetaudio. Mix and add the sounds you want (this part can very time consuming) and once you've done that then convert the MP3 file back to OOG and return it back to its orginal folder.
Reece can I ask one favour though....PLEASE DON'T TELL ANYONE MY SOUND MODDING SITES & FREEWARE SOFTWARE SECRETS !
