Well, after having been tinkering with all the possibilities...
Indiana Jones Fate of Atlantis works with speech in the 030 version if you use the original CD that has the monster.sou. If you have the iso just rename it as .rar and then extract it to a drawer to use it
Later in the game you can press F5, Options and change the Speech volume.
I'm trying this with Munt and the Roland emulated on WinUAE.
So the only thing that should be changed in ScummVM AGA is the lack of the ScummVM screen when loading. I think that has to be a very simple thing.