There are some issues with a few of these, and I wasn't certain whether to put them here or in the area for bug discussion. I tried to send a bug report, but it would not go through.
In the mission "Turning Point," in the Khitomer Conference area a female alien named Ghissel speaks to you, only she is using Tovan's voitce. As I go through this mission it is very clear that the VO's are very messed up. When speaking with D'Tan, he gives you the option to speak with Tovan, to hear his thoughts. Ghissel's face pops up with Tovan's voice (again) only it says that it is D'Tan who is speaking.
In the mission where you first discover NR, Tovan speaks with Satra's voice.
There are also one or two places where the VO cuts out; you'll have a line with voice and then a line without, a line or two with, and then a line without again.
That said, I really have enjoyed the VO work, especially the depth of the emotion that many of the characters display. Very nicely done.