Qwen Streaming ASR
Uses Alibaba Cloud Qwen Server VAD to detect speech boundaries while producing preview and final
transcripts. It reports facts only: speech.started/stopped are observational Events and final
transcripts go to builtin.voice_turn_controller for turn admission and cancellation decisions.
| Property | Value |
|---|---|
| Node type | qwen.asr_realtime |
| Layer / kind | algorithm / transform |
| Capability | speech.vad_asr.streaming |
Ports
| Port | Direction | Schema |
|---|---|---|
audio_in |
Input Audio | PCM S16LE, 16 kHz, mono, streaming |
speech_out |
Output Event | Server-VAD speech.started / speech.stopped |
signal_out |
Output Signal | Legacy graphs only; new graphs leave it disconnected and legacy mode disabled |
transcript_preview_out |
Output Text | Partial transcript |
text_out |
Output Text | Final transcript committed after Server VAD closes the turn |
event_out |
Output Event | Transcript failure state |
Configuration
model defaults to qwen3-asr-flash-realtime; language defaults to zh. Demo 2 uses a
vad_threshold of 0.45: lower values trigger speech more easily, while higher values reject
more low-energy sounds. silence_duration_ms tunes utterance completion. To tune sensitivity,
select qwen-vad-asr on the Studio canvas, change vad_threshold in Configuration, then
select Validate and Save graph. Configure the shared dashscope Connection.
The Node emits provider-neutral semantic Frames only. Demo 2 fans its Text and Event outputs into
both Graph processing Nodes and the project-local Voice Room protocol Node. If vendor events are
reordered, the Node waits for speech.stopped before committing text_out and drops previews that
arrive after Final, so the Graph needs no separate Turn Context Node.
The ASR provider exposes no cancellation Signal and makes no filler, cough, or short-utterance
decision. Admission and cancellation policy belongs exclusively in the Voice Turn Controller.
See Alibaba Cloud's Qwen real-time speech recognition guide for the current protocol and model scope.