Dictation speech models tested on real speech, 2026-10-22

This is the record behind QUILL’s dictation model advice: which models QUILL, QUILL Lite and QUILL Transcribe recommend, which were removed, and why. Every number on the help pages, in the release notes and in the apps’ own recommendation comes from this run. Until this run, the advice rested on ten recordings of a synthetic voice, which flattered every engine.

In one minute

How it was tested

The recordings. Real people, never a synthetic voice:

Set What it is Recordings Licence
LibriVox held-out, English Public-domain audiobooks catalogued on LibriVox after every model’s training cutoff, scored against the Project Gutenberg text. No model can have trained on them, so this is the fairest test. 101 Public domain
LibriVox held-out, Spanish The same, in Spanish 82 Public domain
LibriSpeech test-clean Read audiobook speech, clear recordings 200 CC BY 4.0
LibriSpeech test-other Read audiobook speech, harder voices and recordings 200 CC BY 4.0
FLEURS English (US) Google’s read Wikipedia sentences, many speakers and accents 200 CC BY 4.0
FLEURS Spanish The same, in Spanish 200 CC BY 4.0

LibriSpeech and FLEURS are public, so some models may have trained on them; those results are shown, but the decisions lean on the held-out audiobooks.

The harness. scripts/dictbench.py, run by scripts/bench_machine_run.py, feeds each recording to a model the way dictation does: one phrase at a time, on one processor thread (the speed budget is per thread, because the screen reader needs the rest), on the processor only. Each model runs in its own process, so its memory figure is its own. Word errors ignore capitals and punctuation; for Spanish they also ignore accents.

The measures.

The computer. An Intel Core Ultra 7 265H laptop (16 cores, 64 GB), Windows 11, Python 3.14.8, sherpa-onnx 1.13.8, ONNX Runtime 1.31.0. It is much faster than the computers the advice is written for, which is why speed is judged as a multiple of Moonshine tiny’s rather than in raw seconds.

The limits. One computer, one day. Other work was running during some of the sets, so the absolute speeds vary from set to set; the speed factors in the catalogue come from the English FLEURS run, where eight models ran back to back under the same conditions. Screen-reader lag, battery draw and a real 4 GB computer with NVDA or JAWS running were not measured here; that check (B-8 in the dictation plan) still needs a person. Whisper medium and large-v3-turbo were too slow to re-run and keep their earlier figures.

The results

English

Percent of words wrong (lower is better), speed per thread (0.25 is dictation’s budget) and the most memory used.

Model Held-out audiobooks FLEURS LibriSpeech clean LibriSpeech other Speed per thread Peak memory Decision
NVIDIA Parakeet Unified 0.6B 3.2% 6.3% 1.8% 3.2% 0.21 1.2 GB Recommended on 8 GB with four cores
Whisper medium.en 3.6% - - - 1.55 3.0 GB Removed
NVIDIA Parakeet TDT 0.6B v3 3.8% 9.0% 2.5% 5.2% 0.11 1.1 GB Kept; recommended on 8 GB with two cores
Whisper small.en 4.3% 6.3% 3.4% 7.8% 0.43 1.4 GB Removed
Distil-Whisper large-v3 4.5% - - - 0.82 2.0 GB Removed
Whisper small 4.7% 7.0% 4.2% 8.5% 0.55 1.4 GB Kept; many languages, needs two threads
NVIDIA Nemotron 3.5 Streaming 0.6B 5.3% 13.7% 3.7% 7.3% 0.37 1.5 GB Kept; streams words while you speak
Moonshine base 5.9% 15.1% 4.8% 10.7% 0.05 378 MB Kept; fixed for long phrases
Whisper base.en 5.9% 7.4% 5.6% 11.6% 0.13 820 MB Kept; light, good on varied voices
Distil-Whisper small.en 5.9% 7.6% 4.6% 9.2% 0.22 1.0 GB Removed
Distil-Whisper medium.en 6.3% - 4.2% - 0.47 1.6 GB Removed
Moonshine tiny (built in) 6.5% 13.2% 5.0% 13.3% 0.06 584 MB Kept; the default, and the pick on 4 GB
Whisper base 7.4% 10.8% - - 0.22 821 MB Kept; many languages
Whisper tiny (built in) 8.3% 11.7% 6.7% 13.9% 0.07 521 MB Kept; built in

Spanish

Model FLEURS Spanish Held-out Spanish audiobooks Speed per thread Peak memory Decision
NVIDIA Parakeet TDT 0.6B v3 4.4% 7.3% 0.12 1.1 GB Recommended on 8 GB
Whisper small 6.0% 7.8% 0.57 1.4 GB Kept; needs two threads
NVIDIA Nemotron 3.5 Streaming 0.6B 6.4% 8.0% 0.50 1.5 GB Kept
Whisper base 12.6% 16.1% 0.18 821 MB Kept; lighter
Whisper tiny (built in) 30.5% 27.0% 0.10 521 MB Kept; built in, the pick on 4 GB

The speed column is each model’s middle value across the sets it ran; other work was running during some sets, so these run a little slow. The speed factors the apps use come from the English FLEURS run, where the models ran back to back: against Moonshine tiny, Parakeet TDT v3 costs 3.2 times as much, Parakeet Unified 3.8, Whisper base.en 4.3, Nemotron 5.8, Distil-Whisper small.en 7.9 and Whisper small.en 14.5.

What changed in the apps

QUILL, QUILL Lite and QUILL Transcribe share one dictation engine and one catalogue, so all three changed together.

What this run could not settle

The data

Every row above is in dictation-real-speech-benchmark-2026-10-22.json beside this page: model, set, dataset, words wrong, speed, peak memory, punctuation scores and the number of recordings. The harness is in scripts/ and the datasets, with their licences and checksums, are listed in scripts/bench_datasets.json. The full engineering record is section 36 of the dictation plan (docs/design/2026-10-05-dictation-plan-and-status.md).