Enterprise voice AI platform Rime has announced the successful completion of a $24 million Series A funding round led by M13. The investment also attracted participation from Twilio Ventures, Corazon Capital, and existing investors including Unusual Ventures.
Alongside the funding announcement, Rime revealed that Morgan Blumberg, Partner at M13, has joined the company’s Board of Directors. The newly raised capital will be used to expand Rime’s proprietary conversational speech dataset, strengthen its engineering and research teams, and scale the company’s infrastructure to support continued growth.
Rafael Valle Joins as Chief Science Officer
In addition to the funding, Rime announced the appointment of Rafael Valle as its new Chief Science Officer. Valle previously led audio research at Meta’s Super Intelligence Lab and will play a key role in accelerating the company’s research initiatives and product innovation in enterprise voice AI.
Rime Focuses on Building Better Voice Interaction
While many companies developing voice AI concentrate primarily on making speech sound more natural, Rime has adopted a linguistics-first approach to conversational intelligence.
The company was founded by Lily Clifford, who began the venture while pursuing a PhD in linguistics at Stanford University, alongside Brooke Larson, a PhD linguist and former Amazon Alexa researcher, and Ares Geovanis, a Stanford engineer.
By combining academic speech science with one of the world’s largest collections of expressive multilingual conversational speech, Rime aims to develop voice interaction models capable of delivering more meaningful and contextually appropriate conversations.
According to the company, the future of voice interfaces will not be determined solely by larger AI models, but by the ability to understand, measure, and design what effective human conversation truly sounds like.
CEO Highlights the Importance of Linguistics in AI
Lily Clifford, co-founder and CEO of Rime, said many of the most important aspects of human conversation—such as response relevance, empathy, and conversational appropriateness—remain difficult to measure through conventional engineering methods.
She explained that Rime views voice interaction as a design challenge as much as a technical one. The company is developing voice interaction models where linguistic expertise plays a central role in research and product development. Clifford added that the latest funding, combined with Rafael Valle’s appointment as Chief Science Officer, will significantly increase Rime’s investment in conversational data to help define the future of conversational general intelligence.
Rime Powers Nearly 100 Million Calls Every Month
Rime’s platform currently supports nearly 100 million phone calls each month for major organizations including Mayo Clinic, Dialpad, Upstart, and Asurion.
By focusing specifically on the voice modeling layer and leveraging its linguistic expertise, Rime has gained strong adoption across industries such as healthcare and financial services, where accurate pronunciation of specialized terminology and regulatory compliance—including HIPAA requirements—are essential.
Upstart Highlights Importance of Voice Accuracy
Shiv Indap of Upstart noted that accuracy is critical for maintaining customer trust in financial services, where voice AI must handle complex conversations with precision.
According to Indap, Rime’s ability to manage sophisticated financial interactions enables the company to deliver customer experiences that better address users’ needs.
Independent Study Validates Rime’s Performance
Rime’s technology recently received independent validation through a study conducted by Miravoice, which evaluated 12 voice models from three vendors across 100,000 phone calls.
The study found that Rime’s voice models achieved statistically significant reductions in “Hung Up During Intro” (HUDI) rates compared to competing providers. In addition, Rime recorded the fastest median call completion time among all vendors evaluated.
The findings suggest that conversational elements such as cadence, pacing, and speech delivery can have a measurable impact on business performance by encouraging customers to remain engaged during voice interactions.
M13 Sees Strong Potential in Rime’s Approach
Morgan Blumberg, Partner at M13, said the design principles that will shape the next generation of speech-to-speech AI systems are still being established.
He believes Rime is laying the foundation for future voice AI infrastructure by combining advanced artificial intelligence with deep linguistic expertise. Blumberg added that the company’s leadership team has successfully merged world-class AI research with speech science to develop real-time voice technology capable of serving complex and highly regulated enterprise environments.