Special Headset Commands
The following commands should be spoken into your headset during gameplay to activate the corresponding team actions:
"Bravo defuse bomb": Point your crosshairs on the bomb and say the phrase to defuse it.
"Bravo open door": Point your crosshairs at door and say the phrase.
"Breech, bang, clear": Point your crosshairs into an open room to get your team to throw grenades inside.
"Hands up, get down": Say this phrase while you are behing your enemy to capture them
"Team low profile": Say this phrase to get your crew into stealth mode.
Unlock Terrorist Weapons (single play)
To unlock the terrorist weapons, which you can find in the armory) finish the game on Ensign difficulty.
Unlock Multiple Grenade Launcher (single play)
To unlock the Multiple Grenade Launcher, beat the game on Lieutenant difficulty.

Unlock Level Select
Complete the game on Lieutenant JG difficulty to unlock level select.

Unlock New Difficulties
You can unlock the following difficulties by completing the corresponding tasks:
Lieutenant JG: Beat game on Ensign difficulty
Lieutenant: Beat game on Lieutenant JG difficulty
Lieutenant Commander: Beat game on Lieutenant difficulty
Commander: Beat game on Lieutenant Commander difficulty
Captain: Beat game on Commander difficulty
Rear Admiral: Beat game on Captain difficulty
Admiral: Beat game on Rear Admiral difficulty