The "background" music and sounds are significantly louder than the speech when people talk on my phone or report news from INN. Is there any way to turn down the volume on the background? It makes it difficult to understand the speech without having the volume up so loud that the background begins to hurt after awhile.

Thank you for the confirmation. Too bad that that means this game is unplayable for me. By the time I have the volume up far enough to understand the speech, the other sounds literally cause me physical pain.

Oh well. At least now I know, and knowing is half the battle... (Sorry, reference to a cartoon from my childhood there)

Well, if you know how to edit audio, you could theoretically dive into the files and invert the abient audio over the premixed videos to quiet the ambience...

You can't separate speech from other SFX in the game, but you can turn down the ambient audio (like the buzzing in the TSA's command center, the alarms in NORAD, etc.) by hitting escape and moving "ambience" down a couple notches.