is it possible to add voicelines instead of just replacing them?

I've been thinking about if a VO expansion mod could be possible (There are tons of unused lines to make this so), but i don't even know if u can add voicelines to the game instead of replacing, can u?
Info
if you mean add more lines that the heisters already get called on by the game, then wwise is how you do it
Sorry, i misworded my question , i meant
Can you add new triggers ingame for custom voicelines?
i.e
Kill 5 cops = use unused wolf kill line.wav
Take out FBI van = Use voiceline that is an insult