I noticed that sounds are in separate files in the game install directorie.
The question is, can I manually add other sound files to those directories or change the ones that are there?
And if it can be done, with what do you convert to .sfo ?
I am not sure (Janne is "codemaster"), but there are several steps in the game, that counts checksums etc etc, which are made to find out, that "used version is correct and uncorrupted". I think, that if you are going to modify any of game files, it will notice them and some problems may occur. Note also, that there will be LOTS of more these sounds and many of these are "said only when something happens". If you then wrongly modify these samples, there might be a mess without no sense. So, I recommend you not to do anything for them. But if you still want to try it, create a back-up before you start ;)
...and I dont know anything about that sound format. Songs are played by using ogg-vorbis (read game credits at the end screen).
Will there ever be english game sounds,like when guys meet at the start and comments during gameplay in future versions?
I think no. But I will not say "never", because things will change. Lets wait full finnish voice-packet first. After this it is easier to create other language-packets also.
I've noticed that some sounds can access with Audacity (.sfx). But speech sounds can't (.sfo). Are they crypted or something?
Hmm.. I dont know. These are ogg.vorbis sounds.. but I am not the right person to answer this.