# Sonic 3.6 launch evaluation: Voice Benchmark Profile

> Cartesia’s August 27, 2026 launch post reports independent controlled-voice Elo ratings, blind preference win rates against Eleven v3, response latency, and locale coverage for Sonic 3.6.

- Scope: independent controlled-voice Elo versus Sonic 3.5 and Eleven v3, blind head-to-head listener preference by locale, reply latency, and locale count
- Measurement lanes: Voice experience, Latency
- Primary metric: Elo rating and preference win rate (higher is better)
- Available evidence: Exact figures published in the official launch post
- Owner: Cartesia
- Source snapshots refreshed: 2026-09-11

## Interpretation limit

Provider-reported results; the Elo figures are Cartesia’s citation of an independent speech leaderboard at launch and the preference tests are Cartesia-run.

## Primary sources

- [Owner page](https://www.cartesia.ai/blog/sonic-3.6)

Canonical page: https://benchlm.ai/voice-benchmarks/cartesia-sonic-3-6-launch-evaluation