I’m thinking about appointing a ‘Sound Engineer’ for my games — a person who takes time to learn one or more sound apps or playlists to provide background noises and sound effects for my games. While I’m GM’ing, the Sound Engineer can spool up whatever music or sound effects they like to enhance the game.

Syrinscape.com

Syrinscape.com

Here are some of the RPG oriented sound sites I’ve found:
Right now I’m running a Star Wars game and so this would also be a great resource:
There’s a great discussion of using sounds in tabletop RPG games on StackExchange which also includes these resources:
  • MyNoise.net has highly customizable noise generators (including some directly designed for RPGs, such as this “Dungeon RPG soundscape“)
  • Ambient-Mixer.com has even more free ambient atmosphere compositions (also customizable.) Check out the “Cool Summer Night“, a “Spring Rain“, enter a “Cyberpunk Noir” soundscape, or just go visit “Ravenloft” (not forgetting that you can always mute or even replace certain channels.)
  • Youtube also has many sounds, for exaple the official channel of Cryo Chamber, “a 24 BIT Dark Ambient Music label run by Simon Heath (Atrium Carceri) focusing on high quality dark ambient with a cinematic edge”
Lastly, here are some other resources with RPG sound effects: