Funded: Rime raises $24M to make enterprise voice AI sound more human

Hi there and welcome to Funded, where we spotlight the early-stage bets on the future of tech.

This week, we’re looking at a company betting that the future of voice AI won’t be won by sounding impressive, but by sounding believable. Rime just raised fresh capital to bring more natural conversations to some of the most demanding enterprise environments.

Rime has raised a $24 million Series A led by M13, with participation from Twilio Ventures, Corazon Capital, Unusual Ventures, and other existing investors, to expand its enterprise voice AI platform.

Rime was founded by CEO Lily Clifford, who started the company while pursuing a Stanford PhD in linguistics. Rather than training models on monologues like audiobooks or online videos, the company focuses on real conversational speech, capturing the subtle rhythms, pauses, pitch contours, and even tiny breaths that make interactions feel authentic. The result is voice models designed for industries where trust and accuracy matter, including healthcare, financial services, hospitality, and telecom.

The new funding will help Rime significantly expand its proprietary conversational dataset and grow its research and engineering teams as it works toward what it describes as the first enterprise-ready, end-to-end speech-to-speech model. Alongside the raise, the company also announced the addition of Rafael Valle, formerly Meta’s lead of audio research, as Chief Science Officer.

“The opportunity is building voice models that hold up to real conversation — end-to-end systems that replace the cascaded stack entirely, deployed in verticals where conversation quality can move the business,” Clifford said. “That’s healthcare, financial services, hospitality, and the hardest, most persistent problems in voice that we’re committed to solving.”

Rime says its technology already powers nearly 100 million phone calls each month for customers including Mayo Clinic, Dialpad, Upstart, and Asurion. An independent study from Miravoice evaluating 100,000 calls found that Rime’s voices produced statistically significant lower hang-up rates during introductions than competing providers, while also delivering the fastest median time to completion.

As enterprise AI shifts from chat to voice, Rime is betting that conversation quality is becoming a measurable business metric, not just a technical benchmark.

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This article was drafted with the help of generative AI using company-submitted details, then manually edited and carefully reviewed by a human editor before publication.