Thu Jan 27, 2005 2:34 am by Argh
So, you've recorded RIFF chunks? Well... then ... if my research into this arcane topic serves me right... then you should be able to simply (haha... simply) name all of the chunks using the exact same schema as FL... and then replace the old speech with the new, replacing RIFF chunks as you go.
I have no idea, btw, if there are any additional hazards. I took a look at that issue and ran away screaming, at least for now... FL's sound recording is one of the most hideously complicated things I've ever seen, as it's referring to CRCs which must match database entries associated with Faction_Prop voices... bleah...