---
language:
  - en
license: apache-2.0
library_name: dotcheck
pipeline_tag: audio-classification
tags:
  - audio-classification
  - ai-detection
  - synthetic-media
  - dasheng
  - apache-2.0
  - dotcheck
  - helmholtz
base_model: mispeech/dasheng-base
base_model_relation: adapter
model-index:
  - name: Helmholtz (inhouse-audio@2)
    results:
      - task:
          type: audio-classification
          name: binary AI-likeness (audio)
        dataset:
          name: DotCheck audio holdout (CodecFake / DFADD / AudioGen)
          type: other
          split: holdout
        metrics:
          - name: mean_P_AI_real
            type: mean_score_real
            value: 0.004
          - name: mean_P_AI_ai
            type: mean_score_ai
            value: 0.984
          - name: balanced_accuracy
            type: balanced_accuracy
            value: 0.986
        source:
          name: audio_gates_audio_v2 / Data.json
          url: https://dotcheck.ai/docs
---

# DotCheck/helmholtz-audio-v2

Apache-2.0 audio AI-likeness head for DotCheck. This repo includes the live .npz head, model card, license, and notices.

| Field | Value |
|-------|--------|
| Hub id | `DotCheck/helmholtz-audio-v2` |
| Wire id | `inhouse-audio@2` |
| Label | Helmholtz |
| Artifact | `dasheng_base_linear_head_audio_v2.npz` |
| Backbone | [`mispeech/dasheng-base`](https://huggingface.co/mispeech/dasheng-base) (Apache-2.0) |
| Protocol | 4 s / center crop / up to 2 windows / max aggregate (serve may single-pass prewindowed clips) |
| Output | `p ∈ [0,1]` |
| Serve | CPU FastAPI `/v1/analyze-audio`; Express Dashboard + video soundtrack fuse |

## Model description

Frozen Dasheng-Base masked audio encoder + logistic head. Scores how AI-like speech, music, and general audio sound. Product **Covenant** seats soundtrack windows with Muybridge frame bags (AU6 fuse; default `max`) when a video has usable audio. Covenant seating is DotCheck-private; this repo is the open audio person only.

**Files in this repo:** `README.md`, `LICENSE`, `NOTICE`, `CITATION.cff`, and the `.npz` head file(s) listed above.

## Architecture

```text
audio bytes
  → mono 16 kHz
  → protocol window(s) (4 s)
  → frozen Dasheng-Base emb → logistic head → p
  → multi-window: max
```

Missing audio head at serve → `/v1/analyze-audio` returns **503** (fail closed).

## Inference

Open weights: the live `.npz` head(s) in this repo (Apache-2.0), for use with the frozen upstream backbone named above. This is not a transformers `AutoModel.from_pretrained("DotCheck/…")` package.

Product scoring: Check/Dashboard or Pro API (below). Leviathan (shared memory and related product path) is not in these files.

```bash
curl -sS -X POST "https://dotcheck-server-c221c1f32c68.herokuapp.com/analyze-audio" \
  -H "Authorization: Bearer dc_YOUR_KEY" \
  -F "audio=@clip.wav"
```

UI: https://dotcheck.ai/check · Dashboard audio: https://dotcheck.ai/dashboard · API: https://dotcheck.ai/api · docs: https://dotcheck.ai/docs

## Training data

| Split | Content |
|-------|---------|
| Fit reals | LibriTTS + FSD50K (+ music-from-FSD) |
| Fit AI | parler-mini + dasheng-audiogen (+ contingency codecfake-fit / dfadd-fit) |
| Holdout speech | CodecFake / DFADD (sha-disjoint) |
| Holdout music/SFX | AudioGen odd-seed partition |

Evidence: `audio_gates_audio_v2.json` · `AUDIO_GATES_OK`.

## Evaluation

### Holdout (public claim SSOT)

| Metric | Target | Measured |
|--------|--------|---------:|
| mean P(AI) \| real | ≤ 0.12 | **0.004** |
| mean P(AI) \| AI | ≥ 0.85 | **0.984** |
| bal_acc @ thr | ≥ 0.90 | **0.986** |

## Intended use

- Standalone audio AI-likeness in DotCheck inference.
- Soundtrack windows fused with video frames in product serve.
- Citation of the holdout table above.

### Out of scope

- Product scoring SLA / Leviathan / FUP via Hub download
- Courtroom deepfake forensics / speaker identification
- Legal determinations

## Limitations

- Protocol windows are short; long-form structure is not modeled.
- Codec / compression / unseen generators can shift scores.
- Public floats are standalone audio gates; fused video bags are not a separate claim table yet.

## License

[`LICENSE`](LICENSE) — Apache License 2.0 for DotCheck heads in this repo. Upstream backbones: see [`NOTICE`](NOTICE).

## Citation

[`CITATION.cff`](CITATION.cff) · wire `inhouse-audio@2` / Helmholtz@2 · https://dotcheck.ai/docs