Asking about specific tasks for specific games like that is not usually the best route in ROM hacking world, though do mention what game in such things, or at least if you do then show you have made some effort rather than have whatever replies effectively do it all for you.
The 360 does have a native hardware support option for a type of WMA audio (Microsoft's in house format, today is not as well known but was sort of popular back then as Windows Media player was not the worst thing and shipped with Windows and was used to rip CDs) but whether a dev would have used it for effectively audio samples rather than whole tracks is up in the air -- I have pulled out MIDI files, OGM/OGG and more besides, and basic patent law says there will be dozens more (you can't just stick an MP3 in your game and call it a day as you need to pay for the decoders in those parts of the world that think software patents are a good idea, same for video as well).
Anyway so you bought/found something like
and now want that in the game rather than whatever airsoft models they overlayed with a stapler working they called sound effects in the game.
For a game with it already the usual path is to figure out the formats used and replicate things in that, though some will opt to instead make it play their own which can be easier in certain regards (usually more for video and subtitles but audio can be complex enough that engineering an encoder can be harder than sacrificing some space to use wave or something instead).
https://wiki.multimedia.cx/index.php?title=Category:Game_Formats
http://wiki.xentax.com/index.php/Game_File_Format_Central
Two fairly well stocked descriptors of file formats, though probably only a fraction of percent of what is available. You would want to look at files to see if they matched extensions and/or magic stamps* and see what is available from there. Usually you start by overwriting other files to see if you got the items you care about (chances are the rest of the game has a whole bunch of legal/valid formats you can use for that) and then you dig deeper. Names, sizes, directory names, extensions and elimination (if one format is graphics it is probably not going to be sound unless it is some kind of DLC in which a single weapon gets added in as a package, though said DLC might also be a nice compare and contrast assuming it is not on disc)
*can be the better search as nobody wants 100000 files in their base game (50 weapons which is probably an underestimate if
https://callofduty.fandom.com/wiki/Category:Call_of_Duty:_Black_Ops_II_Weapons is anything to go by, reload, reload with last round hold open, jam, operation, fire, fire suppressed, idle animation sounds, select vs semi firing, if there is a bolt action then that too, possibly another if you have to unload your bolt action sniper to change round types to super spicy, fire selector manipulation, under barrel grenade if any... all multiplies up fairly quickly) and instead things might be put into archive formats that don't share the extension even if they are the format underneath it all, to say nothing of extensions not really being a thing in most consoles in the same way it is in user focused operating systems.
It is also new enough that dynamic mixing might be in play here -- firing inside a room sounds very different to wide open field, and assuming silencers are not a laser gun pew as is often the case then it might be a moderated (hah) sound mixed on the fly much like you might get doppler, directional (might also be a thing in this** adding to that pile) and more.
**choice videos for those new to the concept
