For your avatar project, you can decide whether you want subtitles or not. Subtitles can help users understand everything even in noisy environments, as well as users who can't hear so well.
Here is an example on how subtitles would look like:
If you want to enable or disable subtitles, you can navigate to the project, click the gear icon in the upper left corner and toggle the button next to Show TTS subtitles:
