Eleven Labs

Synthesizer V is an innovative music creation tool leveraging a deep neural network-based synthesis engine to produce remarkably realistic singing voices. It features customizable AI pitch generation, unlimited tracks, no core restrictions, VST3/AU plugin compatibility, ASIO support for Windows, Jack support for Linux, Cross-Lingual Synthesis, AI Retakes, Isolated Aspiration Output, Vocal Modes, Tone Shift parameter, Microtonal Adjustment, MIDI keyboard support, a metronome, and Lua/Javascript scripting. This appears to be a groundbreaking tool. (You will need to translate the page from Japanese to your preferred language)

Replica Studios offers an AI Voice Actor Library featuring over 40 voices for use in games, films, and various creative works. Their AI system is trained to replicate the speech patterns, pronunciation, and emotional expressions of actual voice actors. This library is expanding quickly, and Replica supports indie creators and animation studios by enabling them to achieve natural-sounding performances efficiently and as needed. They are also committed to ethical considerations and the security of AI voices, providing tools to ensure voices are utilized positively.

Eleven Labs' platform utilizes AI to produce long-form speech with natural and engaging voices for creators and publishers.