Getting clean voices to sound realistic

Audition (and audio, in general) newb here.  I'm making a short film that consists of two actors whose dialog is applied as voiceover to a shot of an electronic instrument they're using in a lab.  The instrument is all that's shown as we hear them discuss what they're measuring.  I have very clean audio of both actors and have applied it to the video, along with sound effects for instrument fans, room ventilation, button presses, etc., but the audio is so clean it still sounds ... unrealistic is all I can say; like it was recorded in a soundbooth, as, indeed, it was.  I'm sorry if this isn't clearer; as a newb I'm unfamiliar with the terms.  If you understand my problem, is there a fix?  Some sort of filter or effect I can apply in Audition?  I've completed the Lynda.com Audition Essential Basics course, so I know my way around the program, though I'm far from an expert.  Thanks for any tips.