> For the complete documentation index, see [llms.txt](https://docs.siminsights.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.siminsights.com/hyperskill-studio-authoring/authoring-a-simulation/simulation-settings/experience-settings/conversational-ai.md).

# Conversational AI

* **NLU Engine**: The engine used for the Conversational AI system. Try the different options to see which fits your simulation best.
* **TTS Engine**: The engine used for the text-to-speech system.
* **Virtual Person Language**: The primary language for the text-to-speech output. For example, if the response is expected to be in Spanish, select Spanish for better pronunciation.