DeepgramCartesiaAudio matchupSpeech output
Aura-2vs.Sonic 3.6
Which model is better?
Aura-2 is slightly ahead in independent tests, but the lead is not certain.
Pick Aura-2 for
Pick Sonic 3.6 for
Shared tests
Independent evaluators and leaderboards only, the newest shared snapshot per evaluator. With 95 % ranges a lead counts when they do not overlap; for hit rates, when it holds in a 95 % test. Without any uncertainty figure at most “slightly ahead”.
Cekura
Aura-2 slightly aheadAura-2 is clearly ahead in 0 of 9 subtests and slightly in 4, Sonic 3.6 in 0 clearly and slightly in 1. 4 are level.
Cekura TTS stopping duration
lower is better, as of October 19, 2026
Cekura TTS streaming latency median
lower is better, as of October 19, 2026
Cekura TTS hard-part accuracy: read from context
as of October 19, 2026
Show all 9 subtests
| Subtest | Aura-2 | Sonic 3.6 | Verdict |
|---|---|---|---|
| Cekura TTS stopping duration (lower is better) | 40 ms | 764 ms | Aura-2 slightly ahead |
| Cekura TTS streaming latency median (lower is better) | 126 ms | 270 ms | Aura-2 slightly ahead |
| Cekura TTS hard-part accuracy: read from context | 75.0 % | 58.0 % | Aura-2 slightly ahead |
| Cekura TTS hard-part accuracy: medical terms | 86.0 % | 100.0 % | Sonic 3.6 slightly ahead |
| Cekura TTS hard-part accuracy: codes and addresses | 87.0 % | 75.0 % | Aura-2 slightly ahead |
| Cekura TTS ASR-based hard-part accuracy estimate | 77.2 % | 74.9 % | level |
| Cekura TTS non-streaming latency (lower is better) | 281 ms | 286 ms | level |
| Cekura UTMOS-predicted naturalness | 4 | 4 | level |
| Cekura TTS hard-part accuracy: numbers and shorthand | 71.0 % | 71.0 % | level |
Source · latest October 19, 2026
All data side by side
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