Fermion Research
Speech recognition · Available now

Phonon-1

An open speech recognition model for English: a 415 MB download that runs on a laptop or a datacenter GPU and transcribes an hour of audio in about two and a half minutes.

415 MB
Download, 455 MB on disk
2.640 %
LibriSpeech test-clean
23.9×
Realtime, median of nine corpora
Apache-2.0
Open weights

Phonon-1 is an open speech recognition model for English. It downloads in 415 MB, runs on a laptop or a datacenter GPU, and transcribes an hour of audio in about two and a half minutes. It was trained at 2.4 bits per weight from the start, and it is the second model in the lab’s low-bit lane after Neutrino-1.

Output arrives punctuated and capitalized from the model itself. Phonon-1 powers Detta, the Fermion Research dictation app for the Mac.

Phonon-1the default model
415 MB download · 455 MB on disk
Phonon-1 Microthe smallest model; the accuracy trade is in the table below
285 MB download · 331 MB on disk
Language
English
Audio inputmicrophone or file
16 kHz
Output
Punctuated, capitalized text

The Phonon-1 Micro spec

Benchmarks

BenchmarkPhonon-1415 MBPhonon-1 Micro285 MBParakeet-0.6B 4-bit637 MBMoonshine base248 MBWhisper large-v3-turbo1,619 MBWhisper small967 MBwav2vec2-large1,262 MBQwen3-ASR teacher1,569 MB
LibriSpeech test-clean2.6403.0022.1863.4172.103.4†2.8†2.235
LibriSpeech test-other5.6996.5113.9378.2624.077.6†6.3†4.618
TED-LIUM3.4213.8782.8295.2722.889
SPGISpeech4.1634.8584.1045.7312.79†13.31†3.074
VoxPopuli8.3949.1776.34510.47011.22†7.151
GigaSpeech11.39611.8829.61412.1148.52†9.321
Earnings-2212.57114.77111.19017.87211.07†36.28†11.188
AMI13.08414.09412.72317.79015.16†12.560
Macro, eight benchmarks7.678.526.6210.16.63
Word error rate, percent; lower is better. Measured on the published harness: full test sets, Whisper English text normalizer, greedy decoding. † published figure. – no comparable published result.

Speed

Median 23.9× realtime across nine corpora on a base M5 MacBook Air.

Phonon-1
p50 262 ms · p95 629 ms
Fastest build of the family
p50 203 ms · p95 446 ms
Per-utterance dictation latency on the same machine; p50 and p95 over the same utterance set.

Run it

$ pip install fermion-research
$ fermion transcribe recording.wav

One-shot file transcription. fermion listen transcribes the microphone live; fermion serve exposes an OpenAI-compatible transcription route.

$ fermion listen
$ fermion serve
$ docker run --rm --gpus all ghcr.io/fermionresearch/phonon-cuda:latest \
transcribe recording.wav

The container transcribes recordings of any length, streams over WebSocket, and serves the same endpoint as fermion serve.

The same weights run on a Mac (via MLX) or an NVIDIA GPU; the CUDA runtime and Docker image are in the GitHub repository.

Weights on Hugging Facefermion-research on PyPICUDA runtime on GitHub

Availability

Phonon-1 ships as public weights on Hugging Face, a command line on PyPI, and the CUDA runtime on GitHub. No waitlist, no gated preview.

Speech recognition that stays on the device.

Open weightsApache-2.0

License

Open weights under the Apache License 2.0. Commercial use, modification, fine-tuning, and redistribution are permitted, with no access request and no acceptance form. The model is a derivative of Qwen/Qwen3-ASR-0.6B, itself Apache-2.0; the command line is Apache-2.0 too.

Citation

@misc{fermionresearch2026phonon,
  title  = {Phonon-1},
  author = {{Fermion Research}},
  year   = {2026},
  url    = {https://fermionresearch.com/models/phonon-1/}
}

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