Hi, all,
I’m going to be DMing a session where the players try to make their way through the Drow city of Erelhei-Cinlu, a cesspit of decadence and temptation, with mind flayers and daemons just walking around going about their business.
I’m looking for suggestions for background ambiance, not battles, but just the background sounds of a sinister creepy underdark metropolis.
thanks in advance!
You’ve just inspired me to have a go at making one! but until then how about Brindol Town for your basic town sounds but then mixing in some sounds from Hell to take away the pleasantness of Brindol, demon hisses, chilling winds and that sort of thing. You can also add some spider hisses from BC Tillers Marsh or from the Sci-Fi Insect Hive set 
I did something similar to Steve when I made a custom soundset for Skullport (under Waterdeep). I also used Brindle Town for a base, then added in some weird growls from Witchwood, along with “ghosts passing by” from Abandoned Desert House. I also put in some sounds from Spooky (which is just generally freaky and adds to unease), as well as the “hisses” and “she’s angry now” elements from In the Siren’s Lair. I put in some of the growls and curses of Bugbear battle (though softer) too. The Siren’s Lair/Bugbear Battle sounds gave me some foreign-sounding language elements that added to the player’s sense of “we’re in a place no one will understand us.” For a drow city with some really oddball things, maybe check out the Catacombs set in the Burnt Offerings, and use some of the “zombie bumps” and similar sounds, as they could be the odd sounds of mind flayers and beholders.
Hey, these are all great. Thanks for all the suggestions!
Heck, almost forgot, what Drow City could be complete without a few screams from unfortunate souls? Dungeon Depths has a “distant screams” element that’ll add a nice touch of the macabre to your players’ sojourn into the Underdark.