Mirelo Bags $41 Million in Seed Round Co-Led by a16z and Index

Mirelo AI, developing everything from the foundational AI model to the end product for full control, focused on audio, led by Carl Johann SIMON-GABRIEL, Florian Wenzel, and others, has secured a $41 million seed round, co-led by Index Ventures and Andreessen Horowitz, with participation from Atlantic.vc and TriplePoint Capital.

The funding marks a major milestone in reimagining how audio is created and experienced in videos and games.

Mirelo was born out of a love of sound and frustration with how audio has lagged behind visuals in creative technology. As generative video makes visuals faster and more abundant, sound has become the real bottleneck. Audio shapes emotion and meaning, yet is still treated as an afterthought. Even as default sound emerges, creators will always need deeper, more expressive tools to shape how video is truly experienced. That belief led to the creation of Mirelo by two AI researchers and musicians. The goal is to transform sound design for video by making high-quality audio accessible to everyone while giving professionals deeper creative control. Instead of manual syncing or stock libraries, creators can generate a perfectly synced first draft in seconds, then refine mood, tension, and tone until the sound truly fits the story.

Mirelo already lets creators upload any video and generate high-quality, perfectly synced sound effects in seconds. But the goal goes beyond speed: the company is building a foundation model for the sound layer of video, supporting everything from rapid experimentation to professional-grade workflows and consistency at scale. The long-term vision is to become the audio layer for all visual content, across video, gaming, social media, and film, and to redefine how sound brings emotion and impact to audiovisual experiences worldwide.