Gradium, a Paris-based startup building voice AI models, has reopened its seed round to new backers including Nvidia, bringing the round's total to $100 million. The company said on Thursday that it will use the money to open an office in the San Francisco Bay Area and compete for talent, positioning itself closer to leading US AI firms such as Anthropic, Google, Meta and OpenAI. The move is notable because Paris is itself a significant European AI hub, making the expansion a telling acknowledgement of Silicon Valley's pull.

Gradium emerged from stealth in December with $70 million from investors including FirstMark Capital, Eurazeo, DST Global Partners, Eric Schmidt and French telecoms billionaire Xavier Niel. It was spun out of the French AI lab Kyutai and co-founded by Neil Zeghidour, a researcher formerly at Google Brain, DeepMind and Facebook. Its focus is audio models that deliver voice at scale with ultra-low latency, avoiding the awkward pauses common in AI conversations. Despite competition from the likes of ElevenLabs, valued at $11 billion, and Google's Gemini, Gradium says it has already won major customers, including carmaker Renault.