AI

1. Introduction AI evolution is penetrating our lives and business at an unprecedented speed. The competition is fierce with OpenAI’s ChatGPT and Google’s Gemini. The field of “speech synthesis” that generates voice from text has also achieved remarkable development alongside generative AI innovation. This article summarizes Google’s recently released Gemini 2.5 TTS, OpenAI TTS, and the long-popular VoiceVox’s Zundamon. Name Release Date Main Features Zundamon June 2021 (VOICEVOX) ・Free & commercial use (VOICEVOX) ・Brother character of Tohoku Zunko ・Rich character art and MMD materials OpenAI TTS November 6, 2023 (OpenAI Dev Day) ・Realistic synthetic voice (6 types) ・Integrated text-to-speech conversion ・Voice personality & emotion expression possible Gemini 2.5 Pro March 25, 2025 (Experimental) May 6, 2025 (Preview) ・Google’s cutting-edge AI model ・Advanced reasoning & coding capabilities ・Multimodal support (text, voice, image, video) 2. Audio Output Test Seeing is believing, but hearing is even better. I’ve generated some outputs, so please listen. ...