French voice AI startup Gradium has raised around $30m in fresh funding, extending its seed round to over $100m seven months after launching.
The extension was backed by new investors including US chip titan Nvidia. Gradium did not share which other investors participated in the new round, and declined to share its latest valuation.
It follows a first tranche of $70m which Gradium secured at the end of last year, led by US VC Firstmark and French investor Eurazeo.
Other investors in the company include French billionaires Xavier Niel and Rodolphe Saadé, and former Google CEO Eric Schmidt.
Gradium spun out of Kyutai, a non-profit AI research lab based in Paris and launched in 2023 with €300m in backing from Niel, Saadé and Schmidt. Kyutai is dedicated to open-source AI research, and has so far largely focused on voice AI.
What does Gradium do?
Gradium is building tools to help developers create voice applications. The company offers AI models for real-time text-to-speech and speech-to-text, as well as voice-based translating tools and models specialised for smaller ‘edge’ devices like laptops and phones.
The startup has also created an open-source framework to make it easier for developers to build voice agents.
Enterprises in sectors ranging from customer relationships to healthcare are using the technology, according to the company, for applications ranging from medical secretaries to creating characters for video games.
The fresh injection of cash will enable the startup to open a new office in San Francisco, and to accelerate research efforts and product development.
Voice AI heats up
The voice AI sector is heating up, led in Europe by London-HQ’d scaleup ElevenLabs, which is reportedly targeting a $22bn valuation on the secondaries market.
US AI giants like OpenAI are also actively building voice AI technologies.
Sifted data shows AI-native startups dedicated to voice applications in Europe have raised €536m in the first half of 2026, nearly 50% more than the €360m they raised over the same period in 2025.
“The voice AI sector is strongly accelerating,” Gradium cofounder Neil Zeghidour tells Sifted. “Thousands of startups and enterprises are using voice models to build new applications, but there are less than a dozen players capable of training these models at scale.
“There is therefore intense competition when it comes to the models themselves, but concentrated between a limited number of players.
“We are publishing new models almost every month, whereas development cycles are usually much longer — between six and twelve months — for some of our competitors.”
