Audiobox is a sophisticated tool that can generate voices and sound effects based on voices and natural language text prompts. It lets you create your own audio, including sound effects, and offers interactive audio demos. It's geared for creative, experimental people, but be warned that it can spit out nonsense sometimes.
If you want royalty-free AI-generated sound effects for videos and games, AI Sound Copilot is a good option. It generates sound effects based on text prompts and guarantees that all the sound effects it generates are royalty free, so you don't have to worry about licensing. It's a good option if you don't want to spend time hunting for the right sound effects.