You can get a few addons to change the volume of in game sounds, one is EarPlugs, which reduces the volume of the hunters guns, another is called STFUkazzak, which makes kazzak do just that... So here's my request >_< An addon which can change the volume or totally mute various ingame sound effects.
Off the top of my head I can think of, or have heard people comment on;
Noise of hunters pets, croccolisks, owls/birds (screech), some cats (wierd constipated sound..)
Noise of hunters guns
Strange consortium Noise from electrical devices - for example in ManaTombs
The 'pulse' drone sound around the mana forges in netherstorm
The first two are my personal pet hates, the others I've heard others comment on that they find the sound irritating as hell.
So hows about it, an addon which allows you to change the volume of various in game sound effects, or mute them totally. I've done a bit of digging on this, and as far as I know changing these sound files is allowed, I say this because they removed the ability to change the sound files in one patch, then re enabled their modification in a later patch, if you know different, have a blue post to link.. Please do so..
It'd take hooking the sound playing functions, and then altering the volume to a lower setting, and then on a timer resetting it back to what it was.
The only real issue with this of course is that the author of such a mod would have to collect the length of every sound in the game, and that'd be quite an amount of work. Unless of course a generic time was used, but that might not work so well.
True enough! The only reason I suggested what I did was because the OP asked for reduced volume, rather than removed sounds. But you have a valid point, with the really obnoxious sounds, even removed sounds might likely be better.
It's a shame though that none of the sounds go through the client's functions. I would be tempted to think that it's inconsistent with the way the rest of the UI works... but then I realised that the sounds work on a 3D plane, and Blizzard won't let us touch anything that affects anything more than a 2D plane, out of fear of exploits.
So I suppose it makes sense that that doesn't work, but it really is a damned shame. The only other way would be to put modified versions of the sound in the Data folder, but Blizz tends to freak out about Data folder-based changes, and it has lead to people being hit by the ban-hammer. So I'm out of suggestions and thoughts. :/
Hell... if someone lists the files they want quietened, I'll unpack the MPQs and tinker around with them in Audacity myself. I don't at all mind helping out, and this would help my Hunter too as those gun sounds are a bit deafening.