OnomatoPedal, often abbreviated as OP, is an innovative audiovisual playground that creatively merges onomatopoetic words with interactive music-visual experiences. The project began as a friendly collaboration among musicians and multimedia artists, fostering an environment that encourages creativity and exploration in sound. Each OP version features unique sound sources inspired by Japanese onomatopoeia, with twenty-two initial iterations launched from 2020 to 2021. Going forward, the release of Version 2 OPs in October 2023 adds more complex interactions between sound and visuals, enhancing the playability and creativity for users. As a non-profit and open-source initiative, OnomatoPedal allows for commercial use of its samples and music, promoting wider artistic engagement across various platforms and communities.