VoxRT/wake-word-hey-assistant-vxrt
"Hey Assistant" wake-word on the VoxRT runtime
An always-on wake-phrase detector for the phrase "Hey Assistant". ~100 KB .vxrt model, ~48K parameters, streaming 16 kHz mono input, sigmoid-score output. Trained in-house on synthetic data; the weights are not derived from third-party model checkpoints subject to attribution or copyleft requirements.
Ships on Android, iOS, Linux aarch64, and the browser (WASM SIMD128). On the smallest supported hardware — a $15 Raspberry Pi Zero 2 W — it holds the always-on hot loop at 5.3 % of one A53 core, sustained.
Try it live in your browser: the @voxrt/wake-word-browser npm package + the HF Space at hf.co/spaces/VoxRT/wake-word-browser-demo (see the "About the Space" note at the bottom of this card if the Space link is still pending).Model quality
Test split: 5,240 positive utterances + 6,416 hard-negative utterances (isolated "Hey", isolated "Assistant", competitor wake-words like "Hey Siri", phonetic neighbours, arbitrary speech, non-speech audio). All speakers disjoint from train + val.
- ROC AUC: 0.9966
- Average precision (PR AUC): 0.9899
- Default threshold 0.90 hits precision 0.993 / recall 0.982 on the test split.
Full precision / recall / FPR table lives in the Linux SDK README — identical model.
Runtime performance
Cumulative RTF (wall_time / audio_time, lower is better) on a single CPU core, real deployments:
On the SD662 the raw NEON code path is 8.5× faster than the scalar reference (0.182 RTF scalar → 0.021 RTF NEON) — see the runtime methodology at voxrt-wake-word-linux#neon-vs-scalar.
Download & use
The .vxrt file on this HF repo is byte-identical to the one at github.com/VoxRT/voxrt-wake-word-models/releases. Either source is fine — pick whichever your build tooling reaches faster. The file is AES-256-GCM encrypted at rest; the VoxRT runtime decrypts it on load using a master key baked into the compiled SDK binary. The same file ships inside every VoxRT SDK .aar / xcframework / tarball, so most users never touch the .vxrt directly.
The browser SDK (@voxrt/wake-word-browser) bundles a plaintext variant of the model — WASM decompiles, so an encrypted-at-rest scheme with a master key inside the WASM binary would fail to protect anything (see the plaintext-model architecture note at github.com/VoxRT/voxrt-wake-word-linux#security-tiers). That plaintext .vxrt is shipped only inside the npm package, not on this HF repo.
Use with a VoxRT SDK
.vxrt files aren't loadable with transformers, onnxruntime, or any standard HF library — they're a proprietary container the VoxRT runtime reads. Pick one of the SDKs:
- Android — `voxrt-wake-word-android` (JitPack)
- iOS — `voxrt-wake-word-ios` (Swift Package Manager)
- Linux aarch64 — `voxrt-wake-word-linux` (tarball + Python wheel + npm + Go module)
- Browser (WASM) — `@voxrt/wake-word-browser` (npm, ~275 KB total)
Custom phrase — the paid tier
The default model detects "Hey Assistant" only. If your product needs its own wake-phrase (your brand name, a language other than English, multi-phrase detection), that's the paid VoxRT SDK tier — we train, package into .vxrt, and hand back to you with the same runtime performance guarantees.
Contact `help@voxrt.com` for scoping, timeline, and pricing.
Licensing
- Model weights are proprietary to Wiseport Ltd. (trading as VoxRT), trained in-house on synthetic data; they are not derived from third-party model checkpoints subject to attribution or copyleft requirements.
- The VoxRT runtime + `.vxrt` container format are proprietary Wiseport Ltd. IP.
- Redistribution of the
.vxrtis permitted only as an unmodified part of one of the SDK libraries linked above at the version it was resolved with. See LICENSE-BINARY for the full terms.
About VoxRT
VoxRT is a from-scratch on-device inference runtime tuned for streaming audio on commodity ARM CPUs — no GPU, no NPU, no vendor accelerator required. Sister products on the same runtime:
- Voice activity detection: [Silero VAD in `.vxrt`](https://huggingface.co/VoxRT/silero-vad-vxrt)
- Streaming ASR: [NeMo FastConformer streaming-medium-pc](https://huggingface.co/VoxRT/streaming-medium-pc-vxrt)
Commercial integration / custom-model packaging / custom wake-phrase: help@voxrt.com · voxrt.com
About the Space
The interactive browser demo at hf.co/spaces/VoxRT/wake-word-browser-demo is built and maintained by the VoxRT web team. If the Space link above 404s, it's still being staged — check back or grab the same demo experience directly at voxrt.com.