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VoxBar AI

Flagship accuracy without the complexity. No Docker. No limits. Just speak.

Powered by NVIDIA Canary Qwen 2.5B (Speech-Augmented Language Model)

How It Works

VoxBar AI uses NVIDIA's Speech-Augmented Language Model (SALM) — a 2.5 billion parameter model that combines a speech encoder with a full Qwen large language model. This means it doesn't just hear sounds and guess words — it understands context, producing transcription with natural punctuation and intelligent word choices.

Here's what happens, step by step:

  1. Opens your microphone via sounddevice — captures audio at 16kHz, 1024-sample blocks
  2. Buffers 1.5 seconds of audio into a small in-memory buffer (~96KB)
  3. Checks for silence — if the RMS energy is below 0.03, the chunk is discarded (no wasted processing)
  4. Writes a tiny temp WAV file (~48KB) to your system temp folder
  5. Feeds the WAV to the SALM model with a structured chat prompt: "Transcribe this audio to English"
  6. The model generates text using its LLM backbone — producing accurate, contextual transcription
  7. Token output is decoded via the model's tokenizer into readable text
  8. Temp file is immediately deleted — nothing accumulates on disk
  9. Text is appended to your textbox
  10. Repeats forever — each chunk is completely independent

Every chunk is a self-contained operation. There's no growing context window, no accumulating state, no connection to maintain. The GPU just processes one tiny WAV file at a time, indefinitely.

Recording Limits

VoxBar AI Has No Recording Limit

VoxBar AI can record continuously for as long as you want — hours, all day if you need it.

Unlike VoxBar Pro, which runs inside a Docker container with WebSocket connections that can drop, VoxBar AI runs natively on your machine. There is no server process, no container, no network connection involved. It's just your Python process, the model in GPU memory, and your microphone.

Why It Runs Forever

  • Each 1.5-second chunk is completely independent — no state carries over
  • GPU memory is fixed — the same model processes the same size input every time
  • No WebSocket, no Docker, no server to crash or restart
  • No context window that fills up or degrades

Auto-Stop Behaviour

  • Silence timeout: 15 minutes (900 seconds) of no detected speech
  • Check interval: Every 10 seconds
  • This means you can pause for a long coffee break, step away from your desk, or sit in a quiet meeting — VoxBar AI will keep waiting patiently for up to 15 minutes before auto-stopping

Real-World Testing (2026-02-17)

During live testing, VoxBar AI ran continuously for over 50 minutes of natural dictation with zero interruptions, zero restarts, and zero degradation. The text quality at minute 50 was identical to minute 1.

Memory & Resource Footprint

Resource Usage Behaviour Over Time
GPU VRAM ~6-8GB fixed ✅ Never grows — same model, same chunk size, forever
RAM ~500MB (Python process + model overhead) ✅ Stable — only the text string grows (negligible)
Disk Zero accumulation ✅ Temp WAV files deleted immediately after each chunk
Network None ✅ Completely offline — no internet, no localhost, no sockets

If you left VoxBar AI running for a 3-hour meeting, it would just keep transcribing every 1.5 seconds without ever stopping, restarting, or degrading. That's a genuine advantage over container-based solutions.

Architecture Advantage

What makes VoxBar AI special: It combines a FastConformer speech encoder with a Qwen 2.5B large language model. This is fundamentally different from traditional ASR models that just map sounds to words. The LLM backbone means:

  • Context-aware transcription — it understands what you're saying, not just what sounds you make
  • Natural punctuation — periods, commas, and question marks appear where they should
  • Intelligent word choices — homophones and ambiguous sounds are resolved using language understanding
  • No hallucination on silence — the silence filter (0.03 RMS threshold) prevents phantom text

What users DON'T have to worry about:
- ❌ No Docker required — runs natively, no containers
- ❌ No internet connection — completely offline
- ❌ No WebSocket connections — nothing to drop or reconnect
- ❌ No session limits — record for hours without interruption
- ❌ No cloud processing — your voice never leaves your machine
- ❌ No API keys — the model runs locally
- ❌ No usage limits — unlimited transcription, forever

What users DO need to know:
- ⚠️ Text arrives in chunks (every ~1.5 seconds), not word-by-word like VoxBar Pro
- ⚠️ NVIDIA GPU required — the SALM model needs CUDA
- ⚠️ 6-8GB VRAM — needs a mid-range or better NVIDIA GPU
- ⚠️ First launch downloads ~5GB model files (cached after that)

Accuracy & Speed

Metric Value
Delivery Chunked — text appears every ~1.5 seconds
Latency ~1.5-2 seconds from speech to text (chunk processing time)
Word Error Rate ~5.6% (benchmark) — real-world accuracy matches VoxBar Pro
Inference Speed 418x real-time
Punctuation Yes — context-aware, natural placement
Capitalisation Automatic, intelligent
Hallucination Filter Built-in — discards filler words (um, uh) and noise patterns

Real-World Accuracy

During live testing, VoxBar AI captured natural dictation with zero editing required. Every word was captured accurately, including technical terms, proper nouns, and conversational speech. The accuracy is functionally identical to VoxBar Pro (Voxtral) — the only difference is delivery speed.

Hardware Requirements

Requirement Minimum Recommended
GPU NVIDIA with 6GB VRAM NVIDIA with 8GB+ VRAM
GPU (AMD) ❌ Not supported
GPU (Apple) ❌ Not supported
RAM 16GB 16GB+
Disk ~5GB for model (cached in ~/.cache) SSD recommended
OS Windows 10/11 Windows 11
Software Python 3.10+, PyTorch 2.6+, NeMo trunk Included in venv
Docker ❌ Not required

License & Attribution

Detail Value
Model nvidia/canary-qwen-2.5b
Creator NVIDIA
License CC-BY-4.0 (commercially usable with attribution)
Attribution Required — credit NVIDIA in product documentation
Distribution Can be bundled and sold commercially

Compared to VoxBar Pro

Feature VoxBar Pro VoxBar AI
Accuracy ★★★★★ ★★★★★ (identical in practice)
Text delivery Real-time (word by word) Chunked (every 1.5 seconds)
Docker required Yes No
Session stability May need reconnection after 15-45 min Runs indefinitely — tested 50+ minutes
VRAM ~8-10GB ~6-8GB
Silence timeout 5 minutes 15 minutes
Setup complexity Docker + container management Single Python environment
Best for Live presentations, watching text appear Long dictation, meetings, "set and forget"

Bottom line: VoxBar AI delivers the same accuracy as the flagship, with none of the Docker complexity, and it never stops. For users who don't need word-by-word real-time display, VoxBar AI is arguably the more practical choice.