# How Goodcall uses Cartesia

**90 ms**: “Goodcall achieves a 90 ms on average for time-to-first-audio”

As published on [cartesia.ai](https://www.cartesia.ai/customers/goodcall), October 2024. Captured by usedby on 2026-10-08.

- Company: [Goodcall](https://www.usedby.ai/companies/goodcall.md)
- Tool: [Cartesia](https://www.usedby.ai/tools/cartesia.md)

## What the story says

Goodcall runs an AI phone agent for reception, sales and service, and uses Cartesia's Sonic text-to-speech to generate the voices for its agents. It moved all of its text-to-speech generation from ElevenLabs to Cartesia.

Summary written by usedby from the source page, in English. The figures are those of Cartesia and Goodcall, not ours.

> Industry-Leading Latency: With Sonic, Goodcall achieves a 90 ms on average for time-to-first-audio, including both model and network latency, which is more than four times as fast as the performance experienced with Eleven Labs.

- **97%**: “consistently hit 97% interaction rate”
- **2,217**: “Goodcall has switched 100% of their text-to-speech generation for 2,217 unique voice agents from Eleven Labs to Cartesia.”

> I became an early adopter of Cartesia the day they launched as soon as I saw how low their latency was.
>
> Bob Summers, CEO & Founder of Goodcall

## What usedby checked

We compared the story with its live page on 2026-10-08.

- Checked: the figure 90 ms is printed word for word on the page, near the name of Goodcall.
- Checked: the passage quoted above is copied word for word from the page, near the name of Goodcall.
- Checked: the publication date is read from the page’s own metadata, never guessed.
- Checked: Goodcall uses Cartesia. Confirmed line. Latest check across sources: 2026-10-08.
- Not checked: the result itself. We quote it; we did not measure it.

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Source: https://www.usedby.ai/case-studies/goodcall-cartesia · How we check: https://www.usedby.ai/methodology