That problem with non working speech in dos version under DOSBox is caused by cracked DOS executable file of the game. Ripped version without speech.dat which is available on this site, has DOS executable adjusted so it doesn't check cd in the drive and also SPEECH.DAT - cos it's rip. Windows executable of this game, which is also in the archive, is not cracked, because was not needed to crack it - Windows use another way to work with files, so the method, that authors used probably works even with missing files like SPEECH.DAT.
I have adjusted executable for DOS version, that don't need cd but uses SPEECH.DAT, so it... yeaa.. TALK
If anybody wanted it, post here a message, and I will try to place it somewhere...
(or i can say how to adjust it, if placing link to adjusted exe will be violating of rules for this site - it's really simple, if you have nice hexeditor)
Also I'm interested in that US version, which should have another ending. Btw... is that true or only some rumors? Can someone prove, that US version had another ending than UK version?