We have made an audio book (not visual novel) from the text in an e-book with Google Books Partner Center and their AI voices. The audio book contains 13 voices. You can download the audio, but the e-book must be published on Google Books before you can use it to create the audio book. They are pretty good (but not perfect), and the title would not have been published as an audio book if not for those. There is an audio sample when you follow the link.
https://www.erikistrup.dk/eip6_dreamwalker_en.html
Utilizing AI voices (and even art) takes away the practice of actual voice actors/artists who create their craft as a job. You can find voice actors who are more than willing to work on your projects for free if you are not accumulating profit. Don't resort to unethical practices of companies that steal voices without consent.