Then you can only try to uninstall the mod and try installing it again. It might be worthwhile to try downloading and extracting the mod again from the package. I don't think this failure is due to incomplete file extraction, but it doesn't hurt to be sure. Keep an eye for any error messages.
Before you install, you can check that the amber-folder in you main bg2 directory contains a folder called areas. In the areas folder you should see files named from m#ar01 to m#ar06 (four of each with extension .are .mos .tiz and .wed).
This is interesting, by the way. If I remember correctly all other 3 people reporting this problem have been missing the voicing too. So in you case, the .bat was partially executed.