Gradium, a Paris-based startup that offers voice AI models, re-opened its seed round to new investors, including Nvidia, and has now raised $100 million total for the round, it said Thursday.

The company is using the cash to open an office in the Bay Area and compete for talent there, “strengthening its position at the heart of the world’s leading AI ecosystem,” as Gradium put it. Paris is a major European hub for AI, so this is an interesting acknowledgement of the benefits for AI startups in being close to Anthropic, Google, Meta, and OpenAI.

Gradium originally launched out of stealth in December with $70 million from a roster of impressive investors, including FirstMark Capital, Eurazeo, DST Global Partners, Eric Schmidt, and French telecom billionaire Xavier Niel.

The startup was spun out of French AI lab Kyutai (a lab backed by Niel). Both Kyutai and Gradium were co-founded by Neil Zeghidour, a researcher who previously worked at Google Brain, DeepMind, and Facebook.

Gradium is working on audio models that deliver voice at scale with ultra-low latency, meaning AI voices that respond almost instantly, without that awkward pause that often creeps into AI agent conversations.  

The company has plenty of competition, though, from other voice AI startups like ElevenLabs, valued at $11 billion in February, to major model makers known for voice like Google’s Gemini. But Gradium seems to be winning ground anyway. Since its December launch, Gradium says it has landed some big customers, including French auto manufacturer Renault.