---
title: "Speech models"
description: "Every released Phonon repository, its sizes, and its measured word error rates."
canonical: "https://www.fermionresearch.com/docs/speech-models/"
source: "Fermion Research"
---

Docs / Speech

# Speech models

Every released Phonon repository, its sizes, and its measured word error rates.

## Phonon-1

The default speech recognition model and the one behind `fermion transcribe`, `listen`, and speech serving. It transcribes English from 16 kHz mono audio and was trained at 2.4 bits per weight from the start. The aliases `phonon`, `stt`, and `asr` all resolve to it. Benchmark figures are word error rate; lower is better.

| Download | On disk | LibriSpeech test-clean | LibriSpeech test-other | Eight-benchmark macro |
| --- | --- | --- | --- | --- |
| 415 MB | 455 MB | 2.64 | 5.70 | 7.67 |

## Phonon-1 Micro

The smallest speech model. It trades accuracy for a smaller download and is selected with `--model micro`.

| Download | On disk | LibriSpeech test-clean | LibriSpeech test-other | Eight-benchmark macro |
| --- | --- | --- | --- | --- |
| 285 MB | 331 MB | 3.00 | 6.51 | 8.52 |

## Phonon-1-Big

| Download | On disk | LibriSpeech test-clean | LibriSpeech test-other | Eight-benchmark macro |
| --- | --- | --- | --- | --- |
| 581 MB | 822 MB | 2.67 | 5.72 | 7.60 |

Source: [https://www.fermionresearch.com/docs/speech-models/](https://www.fermionresearch.com/docs/speech-models/)