San Francisco-based voice AI startup Rime announced in July 2026 that it has raised $24 million in a Series A funding round led by M13 Ventures, with participation from Twilio Ventures, Corazon Capital, Unusual Ventures, and existing investors. The company says it is currently handling over 100 million calls per month for enterprise clients.
Founded in 2022 by former Stanford PhD student Lily Clifford, ex-Amazon Alexa engineer Brooke Larson, and Stanford engineer Ares Geovanos, Rime builds voice AI models trained on conversational data the company records itself in its own San Francisco studio, rather than scraping audio from the web. The company says this approach helps reduce the customization burden on enterprise clients. It employs a phoneme-based architecture to handle industry-specific terminology and brand names without requiring customers to retrain models.
Rime serves customers in food service, healthcare, airlines, and fintech, with enterprise contracts from clients including Mayo Clinic, Dialpad, Upstart, and Asurion. The company previously raised $5.5 million in a seed round.
Despite the growth, CEO Clifford acknowledged that voice AI still falls short of replacing legacy IVR systems for most enterprise use cases. “The voice technology is still not there to automate the vast majority of enterprise phone calls,” she said. “Talking with a voice AI agent is not the most compelling experience for the end user. It’s kinda like a new IVR, but with a better voice.”
To address those limitations, Rime is shifting from a pipeline of separate speech-to-text, text-to-speech, and language models toward a unified speech-to-speech approach aimed at reducing latency, improving turn-taking, and handling background noise. The company recently hired Rafael Valle, formerly of Meta Superintelligence Labs and NVIDIA’s audio research team, as Chief Scientist.
Rime plans to use the new funding to grow its 35-person team, with hiring focused on model development, engineering, and partnerships. M13’s Morgan Blumberg is joining the company’s board as part of the deal.
Source: TechCrunch