Tabletop Audio - Tabletop Audio is an ambient game audio site.
ambient-mixer - Listen online to relaxing sound atmospheres, ambient music or chilling sound effects. You can even create and mix your own moods, all for free.
Syrinscape - Immersive, dynamic sound effects and music for tabletop games
BattleBards - Premium audio library for tabletop gaming
MyNoise - Custom shaped online noise machines. Many Many generic sounds
Sound Show - Sound Show is a soundboard application that you can utilize for your project and customize according to requirements.