I’m not a big fan of this for DB.
I search an arcade FPS, not some immersion or emotion (seems like the marketing of cod).
This idea can be cool for Red Orchestra, Insurgency, Takedown or ARMA. But hey, I’m here to straff and spray, while the hud indicate my teammate is down. I don’t want to search where is my teammate thanks to the sound.
The only sounds that could miss in DB are the voices of Quake 3/UT 
(“Impressive”, “Killing Spree”,…)
I think Battlefield 3 does the vocal audio cues the best and really conveys important status cues to your teammates. I wrote about this in another thread of mine. I think it was the HUD and icons thread.
The only issue is like what Darkangel said when you’re being sneaky and your guy yells because that is an audio cue for the enemy too. In Battlefield 3 hearing the enemy works without confusion because of the accent/language differences between the teams (Russian/English).
I’m sure you can YouTube some example as I am on my phone and unable to provide.
Please no. As much fun as that can be in an arena game, that just sounds silly in any other context. I hope if SD includes kill streak notices in DB, they will do it in a way that doesn’t clash with the style of the game. Could be some sort of taunt from your character or a pat in the back from the commander’s voiceover, but please not something that sounds like an overly excited play-by-play announcer for some bloodsport… 