When playing my Necrons, I imagine the weapons producing a cacophony of noise, since subtlety doesn't seem to be their idiom:
Gauss Weapons: A thunderclap of voided atmosphere
Tesla Weapons: The hiss and crackle of a high voltage switch being opened
Particle Weapons: The scream of a very wet or very hungry baby
For the tyranids the only weapon I regularly think about (and vocalize during games!) is the Doom of Malan'tai's' cataclysm. I envision occasional blurts of static, increasing slowly until they overlap at an ear splitting level, followed by the thunderous burst like the orbital bombardment seen in Akira
Dark Eldar: The sound is modulated so each shot is a sound evoking absolute terror. In most cases this is multiple females of the species giggling.
Ask not the EldarGal a question, for she will give you three answers, all of which are puns and terrifying to know. Back off man, I'm a feminist. Ia! Ia! Gloppal Snode!
Well, my sonic weaponry doesn't have firing noises, all they are is speakers with Dubstep playing at the enemy, causing their heads to explode from the awfulness!
It is common debate at my game store between the Noise Marines who use Dubstep, and the Noise Marines that use Death Metal!
Sonic Weaponry is definitely Dubstep, according to Slannesh Simulator 2013 (aka Saints Row IV).
Helpfully, in another thread Meph posted a clip of the exact sound that an Imperial Guard list maxed out on the missile artillery makes: [URL="http://www.lounge.belloflostsouls.net/showthread.php?35387-B-amp-SI-Super-Heavy-Multiple-Launch-Rocket-System-(MLSR)&p=356665&viewfull=1#post356665"]Link[/URL]
Thank you for voxing the Church of Khorne, would you like to donate a skull to the Skull Throne today?
My skaven Mordheim gang squeeks and I make "ratty" with my mouth when they move.
My tomb kings moan like Scooby-Do villains.
My orks talk like British chavs.
Anything las- goes, "pew-pew-pew."
Visit my war gaming blog at: lookoutsir.blogspot.com
just one more reason Slaanesh sucks.
Bolters go Brakkabrakkabkak
Battle Cannons go ka-KOOOOM!!!
Autocannons go duh-Choom!
Meltaguns go phiiiiissssssh!
Plasma Weapons go ZZZZZORRRCH!!!
Chainweapons go bbbrrrRRRRRAAAAWRRRRRR!
Enemies go (bloodcurdling screams)
Berzerkers go 'BLOOD FOR THE BLOOD GOD'
.... i think i just wrote the best children's book ever.
Like God slamming a door.
A fully-automatic, belt-fed door.
I may have mixed my metaphors somewhat.
AUT TACE AUT LOQUERE MELIORA SILENTIO