If you mean the Speech you can use 'Accent' speech packs in place of the stock ones.
'English BBQ Voiceovers' 6th or therabouts down in the list. No idea what they are like - I haven't tried them.
http://mission4today.com/index.php?name=Downloads&c=587
If you mean 'Takeoff' only, you could copy one of the 'carrier' soundtracks found in 'Samples' - 'Sounds' and paste it into the 'Takeoff' folder located in the 'Music' Folder. My current 'Takeoff' track plays in all missions till I'm in the air that is.