Rime secures ? million to improve AI-powered enterprise calls
San Francisco-based Rime announced on Wednesday that it has raised ? million in a Series A round led by M13 Ventures. Founded in 2022, the voice AI startup develops models for enterprise calls and serves customers in food service, healthcare, airlines, and fintech.
Why enterprise voice automation still falls short
Large organizations increasingly use AI for sales, marketing, and customer support calls, but many still prefer legacy interactive voice response systems. Rime co-founder Lily Clifford argues that current voice agents have not yet matched IVR systems in effectiveness or delivered a sufficiently natural user experience.
Pronunciation, latency, turn-taking, and background noise remain significant obstacles. Enterprise deployments also require models to handle brand names and specialized terminology accurately, often forcing customers to invest in industry-specific retraining and orchestration.
“The voice technology is still not there to automate the vast majority of enterprise phone calls. LLMs have made it a lot easier to build voice applications that work, but they haven’t changed how it feels to interact.”
Proprietary data and speech-to-speech models
Rime operates a recording studio in San Francisco to collect conversational data instead of scraping audio from the web. Its phoneme-based architecture is designed to adapt to different pronunciations, reducing the amount of customization required for specific sectors.
The startup initially combined separate speech-to-text, text-to-speech, and large language models. It is now prioritizing speech-to-speech systems intended to lower latency, improve conversational timing, address background noise, and reduce dependence on orchestration across multiple models.
Funding, customers, and expansion
Twilio Ventures, Corazon Capital, Unusual Ventures, and existing investors joined the round. Rime previously raised ?.5 million in seed funding and has won contracts with Mayo Clinic, Dialpad, Upstart, and Asurion. Morgan Blumberg of M13 will join its board.
The 35-person company plans to hire across model development, engineering, and partnerships. It has also appointed Rafael Valle, formerly of Meta Superintelligence Labs and NVIDIA’s applied deep learning audio research team, as Chief Scientist.
For businesses, the practical lesson is to evaluate voice AI on call quality rather than voice realism alone. Reliable pronunciation, response latency, noise handling, and integration overhead will determine whether automation can replace existing phone workflows without undermining customer experience.