Tuesday, March 4, 2025

Sesame: Eerily Realistic AI Voice Demo

In late 2013, the Spike Jonze film Her imagined a future where people would form emotional connections with AI voice assistants. Nearly 12 years later, that fictional premise has veered closer to reality with the release of a new conversational voice model from AI startup Sesame that has left many users both fascinated and unnerved.

"I tried the demo, and it was genuinely startling how human it felt," wrote one Hacker News user who tested the system. "I'm almost a bit worried I will start feeling emotionally attached to a voice assistant with this level of human-like sound."

In late February, Sesame released a demo for the company's new Conversational Speech Model (CSM) that appears to cross over what many consider the "uncanny valley" of AI-generated speech, with some testers reporting emotional connections to the male or female voice assistant ("Miles" and "Maya").

In our own evaluation, we spoke with the male voice for about 28 minutes, talking about life in general and how it decides what is "right" or "wrong" based on its training data. The synthesized voice was expressive and dynamic, imitating breath sounds, chuckles, interruptions, and even sometimes stumbling over words and correcting itself. These imperfections are intentional.

"At Sesame, our goal is to achieve 'voice presence'—the magical quality that makes spoken interactions feel real, understood, and valued," writes the company in a blog post. "We are creating conversational partners that do not just process requests; they engage in genuine dialogue that builds confidence and trust over time. In doing so, we hope to realize the untapped potential of voice as the ultimate interface for instruction and understanding." (...)

Browsing reactions to Sesame found online, we found many users expressing astonishment at its realism. "I've been into AI since I was a child, but this is the first time I've experienced something that made me definitively feel like we had arrived," wrote one Reddit user. "I'm sure it's not beating any benchmarks, or meeting any common definition of AGI, but this is the first time I've had a real genuine conversation with something I felt was real." Many other Reddit threads express similar feelings of surprise, with commenters saying it's "jaw-dropping" or "mind-blowing."

While that sounds like a bunch of hyperbole at first glance, not everyone finds the Sesame experience pleasant. Mark Hachman, a senior editor at PCWorld, wrote about being deeply unsettled by his interaction with the Sesame voice AI. "Fifteen minutes after 'hanging up' with Sesame's new 'lifelike' AI, and I'm still freaked out," Hachman reported. He described how the AI's voice and conversational style eerily resembled an old friend he had dated in high school.

Gavin Purcell, co-host of the AI for Humans podcast, posted an example video on Reddit where the human pretends to be an embezzler and argues with a boss. It's so dynamic that it's difficult to tell who the human is and which one is the AI model. Judging by our own demo, it's entirely capable of what you see in the video.

by Benji Edwards, Ars Technica |  Read more:
Image: : Moor Studio via Getty Images
[ed. Been hearing about this, and...wow. Pretty realistic (and just getting started). Give it a try (here).]