These two founders left Goldman and Meta to build voice AI for markets everyone else overlooked

The voice AI market is booming, with customer support and service being among the hottest sectors right now. However, building a product that sounds human and responds without noticeable delay turns out to be much harder in some markets than others. Most major players in the voice AI space weren't built with Africa and the Middle East in mind, leaving a gap in the market that AethexAI aims to fill.

AethexAI, a startup founded last year, has raised $3 million in pre-seed funding led by 4DX Ventures, with participation from Enza Capital, Dorm Room Fund, Mojo Ventures, and Stanford GSB 26 Fund. Individual investors include Stanford faculty, telecom executives, and AI researchers from Anthropic. The company was founded by Mariama Diallo and Ayooluwa Odemuyiwa, who left Goldman Sachs and Meta, respectively, to build voice AI for emerging markets.

Rather than using existing orchestration tools like Vapi and LiveKit, AethexAI built its own small model and orchestration layer from scratch to handle the localized dialects of English, French, and Arabic spoken across its target markets. This decision was driven by the particular demands of operating in the region, where latency and jitter on automated calls can be outrageous. "If we had become orchestrators, we might have had to use large models that were hosted outside the region, resulting in higher latency," CTO Odemuyiwa explained.

"We realized that in order for this to work, we have to use very small models and cut latency at every step." The company's approach involves using small models, which are enough to tackle the latency problem while maintaining accuracy. AethexAI developed its own Kora series, with parameters ranging from 300 million to 1.7 billion, a fraction of the size of the largest language models. To train these models, the startup used anonymized recordings from a call center partner and collected audio data from radio stations across Africa.

The company has now handled more than 17,000 calls per day. On the business side, AethexAI is taking care to walk clients who are new to voice AI through the process, offering onsite demos and workshops to help them identify the best use cases for automation. The startup is open to working across all industries, but at the moment, a big part of its use cases involves calls for debt collection, customer activation, or KYC — Know Your Customer verification.

"We always tell customers that we cannot be everything for everybody right now," CEO Diallo said. "We're small. When we start talking to a company, we ask them to pick one use case that is the most important to them to start [with]." Walter Baddoo, co-founder and managing partner of 4DX Ventures, argues that the Africa and Middle East market is fundamentally different from the markets most voice AI companies were built to serve.