Speechmatics Linden is ahead of Google Chirp 3 on time to first text and final-text delay. The Pipecat Dataset and The Ocular Dataset are too close to call.
Last updated Methodology by Dileep Chagam
Each dot is one model. Bottom-left is best: fewer errors and a faster final transcript.
Speechmatics Linden is the better pick over Google Chirp 3 on every measure that separates them: showing words while the caller is still talking (3.29s sooner) and quick turn-taking once the caller stops (328ms sooner). For accuracy on clean, scripted audio and accuracy on real phone conversations, the gap is inside the margin of error, so neither is ahead.
Too close to call: inside the margin of error
Too close to call: inside the margin of error
Speechmatics Linden, 3.29s sooner
Speechmatics Linden, 328ms sooner
Lower is better on every metric. The small figure is each model's place in the whole field. What each metric measures.
Google Chirp 3 shows first text after 7.97s and final text after 1.41s, and Speechmatics Linden shows first text after 2.52s and final text after 213ms, on a bad turn (P95) across the same streamed turns.
| Measure | Model | P50 | P90 | P95 |
|---|---|---|---|---|
| Time to first text | Google Chirp 3 | 4.48s | 6.21s | 7.97s |
| Speechmatics Linden | 1.19s | 1.56s | 2.52s | |
| Final-text delay | Google Chirp 3 | 475ms* | 941ms* | 1.41s* |
| Speechmatics Linden | 147ms | 192ms | 213ms |
* Final-text delay is the observed time after stream close, because controlled finalization is not available for this model. Compare it with care against models that finalize on request.
Place among the 17 models on each metric. Lower is better on all four.
| Metric | Chirp 3 | Linden |
|---|---|---|
| Pipecat Dataset WER | 2.00%3rd of 17 | 2.46%7th of 17 |
| Ocular Dataset WER | 4.19%9th of 17 | 3.93%7th of 17 |
| Time to first text | 4.48s14th of 15 | 1.19s8th of 15 |
| Final-text delay | 475ms13th of 17 | 147ms8th of 17 |
| Model | Pipecat clips | Ocular recordings | Turns timed | Failed |
|---|---|---|---|---|
| Google Chirp 3 | 1,000 | 8 | 206 | 0 |
| Speechmatics Linden | 998 | 8 | 194 | 12 |
Only clips with usable text count, so the two totals can differ. How WER is scored.
Google Chirp 3 and Speechmatics Linden are too close to call on accuracy. On the 1,000 public Pipecat clips, Google Chirp 3 scores 2.00% and Speechmatics Linden 2.46%, with likely ranges of 1.77 to 2.25% and 2.19 to 2.73%. The ranges overlap, so the difference is too close to call. On the eight licensed Ocular recordings, Google Chirp 3 scores 4.19% and Speechmatics Linden 3.93%, with likely ranges of 2.97 to 5.27% and 2.94 to 5.19%. The ranges overlap, so the difference is too close to call. Word error rate counts incorrect, missing, and extra words, so lower is better.
No. Speechmatics Linden finishes the transcript 328ms sooner. Google Chirp 3 has the final transcript 475ms after the speaker stops and Speechmatics Linden 147ms, at the median. Both are measured on the same 206 streamed turns.
Speechmatics Linden finishes the transcript 328ms sooner, and the two are too close to call on real conversations. A voice agent cannot reply until the final transcript arrives, and the Ocular recordings are real conversations.
Yes, both return partial text before the speaker stops. Google Chirp 3 shows first text after 4.48s and Speechmatics Linden after 1.19s, at the median, so Speechmatics Linden is 3.29s sooner.