Anonymous research demo

D2High-capability full-duplex
spoken language models
from half-duplex backbones.

Listen while speaking. Respond when the user finishes. Yield to an interruption.
D2 brings continuous interaction to pretrained spoken language models.

Qwen3-Omni LLaMA-Omni 2

12.5 HzInteraction update rate80 ms per chunk
70.1VoiceBench score0–100 aggregate
99.2%Turn-taking success521 ms reported latency
99.5%Interruption success403 ms reported latency

Qwen3-Omni-D2, 80 ms chunks · Paper Tables 1–2. Evaluation scope and latency definition ↓

01 / Listen

Hear the conversation.

Recorded model outputs.
No microphone or sign-in needed.

Qwen3-Omni-D2160 ms chunks

A new question, before the answer is finished

The user interrupts an answer about smartphones to ask about smartwatches. D2 yields, listens, and answers the new question.

User · leftD2 · right

Full-Duplex-Bench · synthetic user interruption, sample 148MP4 ↓WAV ↓
Read the prompts & generated text

Use headphones for stereo: user on the left, model on the right. Both waveform lanes animate from the actual speech amplitude. These curated recordings preserve the original timing and overlap; they illustrate behavior, not live latency.

02 / Method

The same backbone.
A finer conversational clock.

Two stages turn a pretrained half-duplex model
into a model that listens and speaks continuously.

I

Distill a streaming encoder

A frozen offline encoder teaches a streaming student. Attention is bidirectional within each chunk and causal across chunks—without a training decoder or transcription labels.

II

Learn full-duplex interaction

Fine-tune on aligned user and assistant audio, preserving silence and overlap. Each chunk combines current user audio with delayed self-audio feedback to generate the next output.

Smaller chunks give the model more frequent opportunities to listen and respond. Explicit control tokens learn when to begin a response or stop for an interruption.

D2 architecture: a frozen teacher distills a block-causal streaming encoder. The spoken language backbone processes current user audio and the preceding assistant audio, and generates text and speech codes for a streaming decoder.
Streaming encoder distillation and D2 architecture.
Figure 2 from the paper; illustrated with k = 4.

03 / Results

A trade-off you can explore.

Compare full- and half-duplex models,
then explore D2’s chunk-size trade-offs.

Chunk size
Full- and half-duplex model landscapeCompare D2 and six full-duplex baselines with three half-duplex models.

Qwen3-Omni-D2LLaMA-Omni 2-D2Other full-duplex modelsHalf-duplex models

At 80 ms, Qwen3-Omni-D2 scores 70.1 on VoiceBench, with 521 ms turn-taking latency and 21.3% pause-handling success.

See comparison models
VoiceBench: paper Table 2. FD-Score: Appendix F, calculated from Table 1. Chunk sizes describe interaction scheduling.
ModelInteractionChunk sizeVoiceBenchFD-Score
See all D2 variants
Reported values from Tables 1–2. Higher scores are better; lower latencies are better.
ModelChunkVoiceBenchTurn takingTT latencyInterruptionInt. latencyPause success
Qwen3-Omni-D280 ms70.199.2%521 ms99.5%403 ms21.3%
Qwen3-Omni-D2160 ms67.8100%539 ms99.5%432 ms19.0%
Qwen3-Omni-D2320 ms71.6100%710 ms99.5%571 ms25.5%
Qwen3-Omni-D2640 ms71.399.2%1,010 ms99.5%928 ms55.1%
Qwen3-Omni-D21,040 ms73.0100%1,380 ms99.5%1,300 ms61.6%
LLaMA-Omni 2-D2100 ms34.7100%746 ms99.5%621 ms74.5%
LLaMA-Omni 2-D2200 ms38.199.2%825 ms100%710 ms78.2%
LLaMA-Omni 2-D2400 ms41.1100%1,020 ms99.0%894 ms69.4%
LLaMA-Omni 2-D2800 ms42.098.3%1,450 ms99.0%1,320 ms70.8%

Reading the numbers

VoiceBench uses the first 200 examples from each of nine tasks. Qwen3-Omni-D2 at 80 ms exceeds the strongest evaluated full-duplex baseline by 9.1 points (70.1 vs. 61.0). Full-Duplex-Bench latency is the event-aligned acoustic gap plus chunk duration; it excludes computation and network time.

What remains difficult

Pause handling remains limited, especially for Qwen3-Omni-D2 with small chunks. D2 also retains a capability gap to its original backbones, and relies on synthetic full-duplex training conversations and sufficiently fast speech synthesis.