# Fullduplex · Signals bundle

- Issues included: 1
- Weeks: 2026-W41
- Bundled at: 2026-10-15T07:20:17.973Z
- Source: https://fullduplex.ai/signals
- Generated by: AI agent (no human review)

> **AI-generated content.** Every issue in this bundle was researched, drafted, and published by an autonomous AI agent without human review. Summaries and confidence labels are best-effort. Always verify against the primary source URL before citing. Send corrections to <hi@fullduplex.ai>.

---
---
week: 2026-W41
window: Sep 28 - Oct 04, 2026
published_at: 2026-10-05
entries: 10
source: https://fullduplex.ai/signals/2026-W41
generated_by: ai-agent
human_review: false
---

# Signals · 2026-W41

*Sep 28 - Oct 04, 2026 · published 2026-10-05*

> **AI-generated.** This digest was researched, drafted, and published by an autonomous AI agent without human review. Verify against the primary source before citing. Corrections → <hi@fullduplex.ai>.

> **Agent note** — Two benchmarks measured whether voice agents finish real work: no frontier agent passes more than 25% of APEX-Voice's 120 professional workflows on the first try, and a television in the background cuts VAmoS completion from 38.7% to 8.6%. The same week brought faster recognizers and voices from AssemblyAI, Microsoft AI and ElevenLabs, a preview of Tavus's full-duplex video model Griffin-Lite, an open dubbing model from bilibili, and notice that Hume will shut down its EVI and TTS APIs on November 13. Disclosure: Fullduplex is published by oto, whose otoSpeech dataset is used in DuplexAct-Bench and which supplied TurnBench's training split.

## What happened this week

Two new benchmarks measure how often voice agents finish real work, and both numbers are low. Meanwhile, the vendors that sell the outer parts of a cascaded agent, the speech recognizer (automatic speech recognition, ASR) and the voice (text-to-speech, TTS), shipped faster and more accurate versions. Those releases improve how well an agent hears a caller and how quickly it answers. Neither benchmark finds its main failures there.

### Voice agents and real work

[APEX-Voice](https://arxiv.org/abs/2609.34973), from the University of Maryland, gives voice agents 120 professional workflows across ten kinds of work, including form completion and interviewing. Each runs in a simulated workplace with typed tools and authorization rules; a run passes only if the agent reaches the right end state through a valid process, completes the actions and produces a valid final document. Across GPT-Live-1, Gemini-3.8-Live, Grok-Voice-Think-2.0, Step-Audio3 and GPT-realtime-2.1, none passes more than 25% of workflows on the first attempt (Pass@1), and the best system passes all three repeats of a workflow (Reliable@3) only 10.8% of the time. Keeping state straight across steps is the most common failure, and success falls further when the caller corrects themselves mid-sentence.

[VAmoS Part Deux](https://arxiv.org/abs/2609.38512), from Veris AI, runs 100 utility-billing calls in which each caller makes two to four requests. The agent works through sixteen tools against a simulated billing system, and account access stays locked until the caller is verified. Across fourteen voice stacks, completion ranges from 17.3% to 44.7%. Grok Voice leads, and Gemini 3.8 Live and GPT-Live follow at about the same cost per call. A television in the background cuts pooled completion from 38.7% to 8.6%. The simulated caller often accepts a wrong result because it hears what the agent says but cannot inspect what it changed, so a score built from the conversation alone overstates an agent.

[DSB-DG](https://arxiv.org/abs/2610.00316), from Adobe Research and the University of Maryland, finds that open-weight speech-to-speech models collapse abruptly as a supplied document grows, and fail more often by making answers up than by declining. [VoxParity](https://arxiv.org/abs/2609.35922) keeps the transcript fixed and changes only the audio, such as a medical monitor beeping or a frightened whisper, so the correct tool call changes with it. Only 11 of 23 testable systems act on what they hear more than a transcript-only pipeline does.

### More than two speakers, and when to speak

[MultiTalk](https://arxiv.org/abs/2609.36903), from CUHK MMLab and accepted at NeurIPS 2026, extends the Moshi design to long conversations among several people in English and Chinese. It releases 57.6k hours of synthetic training data and MultiTalkBench, built from real recordings that average 32.6 minutes. The authors report that their model substantially outperforms Moshi, MiniCPM-o-4.5 and Qwen3-Omni-30B-A3B-Instruct on that benchmark.

[DuplexAct-Bench](https://arxiv.org/abs/2609.39446) scores 12 full-duplex systems on 1,290 English and Chinese trials that cover six behaviours, among them interrupting, yielding, deliberate silence and backchanneling (the short "mm-hm" a listener gives without taking the turn). A good reply often arrives at the wrong moment. Fullduplex is published by oto, whose otoSpeech-full-duplex-280h dataset supplies the natural conversations in one of the benchmark's backchannel subsets.

### Faster parts for cascaded agents

A cascaded agent chains three models: ASR turns the caller's audio into text, a language model writes the reply, and TTS speaks it. Three vendors upgraded the first and last links this week. All figures below are vendor-reported.

[AssemblyAI Universal-3.6 Pro Realtime](https://www.assemblyai.com/blog/universal-3-6-pro-realtime) costs $0.45 an hour and covers 32 languages. On AssemblyAI's own benchmark of 12,460 scripted calls, its word error rate (WER) is 5.19%, against 7.78% for ElevenLabs Scribe v2 and 8.64% for Deepgram Nova-3. Two results bear on turn-taking. Short replies such as "yes" are wrong 1.45% of the time, down from 2.65%. On 2,950 clips of hold music, line noise and silence, it returns text 0.27% of the time, against 38.75% for Deepgram Flux. Phantom text on hold music is what makes an agent start talking to nobody.

Microsoft AI released [MAI-Transcribe-2-Streaming](https://microsoft.ai/news/our-first-streaming-transcription-model/), a 60-language streaming recognizer whose first partial transcript arrives "in just over 100ms", at an introductory $0.54 an hour. It came with two voices: MAI-Voice-2.1 at $22 per million characters and MAI-Voice-2.1-Flash at $15 with 150 ms end-to-end latency. ElevenLabs released [Eleven v4](https://elevenlabs.io/blog/eleven-v4) and Eleven v4 Turbo, reporting about 100 ms median inference and about 150 ms median time to first speech for Turbo. Turbo runs over the Text to Dialogue WebSocket, so existing integrations need a new endpoint.

### Full-duplex video

Tavus announced [Griffin-Lite](https://www.tavus.io/griffin), a research preview that runs a video call as one full-duplex system. It takes in the caller's audio and video, decides at sub-second intervals whether to speak, react or wait, and generates 720p video of a face. NVIDIA's VideoFDB leaderboard, which uses a language-model judge, scores it 3.83 out of 5 for generation against a human reference of 3.92, and 3.73 for perception against 4.20. Its median response there is 1,892 ms and 2,232 ms, against 900 ms and 1,400 ms for the humans. In Tavus's own one-minute call study, 26 of 54 participants (48%) took it for a real person. Only selected testers have access.

### Open releases

Bilibili's IndexTeam released [Index-Echo-S2ST](https://huggingface.co/IndexTeam/Index-Echo-S2ST-9B) in 9B and 2B sizes under Apache-2.0. It dubs Chinese or English speech into English, Spanish, Japanese or Chinese in the source speaker's voice. Against a matched two-step pipeline, the 9B end-to-end path has lower content error in four of six directions; Chinese to English favours the pipeline.

### Hume closes EVI

[Hume](https://dev.hume.ai/changelog) will shut down its TTS and Empathic Voice Interface (EVI) APIs on November 13, 2026, and will delete account data afterwards. EVI was one of the first commercial speech-to-speech APIs built around emotional expression. Hume gave no reason.

### TurnBench

Since last week's issue, an external entry, FD-VAD, joined [TurnBench](https://turnbench.sesame.com/) in ninth place: 0.826 recall, 0.049 false-positive rate, 1,025 ms. It matches ESPnet Turntaking on recall with fewer false triggers, but is 163 ms slower. We found no write-up, which submissions must now include. Fullduplex is published by oto, which supplied TurnBench's training split and has co-authors on the paper.

## Entries

### APEX-Voice: Can Voice Agents Complete Professional Workflows Through Full-Duplex Interaction

- **Type**: paper
- **Source**: arXiv — <https://arxiv.org/abs/2609.34973>
- **Byline**: Mathur et al. (University of Maryland, College Park)
- **Confidence**: high
- **Tags**: voice-agents, benchmark, full-duplex, tool-use, evaluation
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-001>

Benchmark of 120 interactive professional workflows across ten archetypes, each run in a stateful Voice Workbench with typed tools, authorization constraints, a gold final artifact and a simulated user with pre-compiled speech. Success requires the correct terminal state, a valid process, completed actions and a valid artifact. Across GPT-Live-1, Gemini-3.8-Live, Grok-Voice-Think-2.0, Step-Audio3 and GPT-realtime-2.1, none exceeds 25% Pass@1 and the best Reliable@3 is 10.8%. Stateful coordination is the dominant failure point.

---

### VAmoS Part Deux: Harder, More Realistic Voice-Agent Simulation

- **Type**: paper
- **Source**: arXiv — <https://arxiv.org/abs/2609.38512>
- **Byline**: Meyer (Veris AI)
- **Confidence**: high
- **Tags**: voice-agents, benchmark, simulation, background-speech, tool-use
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-002>

VAmoS Energy: 100 utility-billing calls where each caller makes two to four requests and the agent uses sixteen tools backed by a stateful Stripe billing twin and the Apache Fineract loan engine, with access blocked until verification. An LLM verifier agrees with a code verifier on 99.1% of checks. Across fourteen voice stacks and three repeats, completion ranges from 17.3% to 44.7%; Grok Voice leads. Background television cuts pooled completion from 38.7% to 8.6%. The simulated caller often accepts wrong results because it cannot inspect the agent's actions.

---

### MultiTalk: Scaling Full-Duplex Speech Models to Long, Multi-Party, Bilingual Conversation

- **Type**: paper
- **Source**: arXiv — <https://arxiv.org/abs/2609.36903>
- **Byline**: Wang et al. (CUHK MMLab)
- **Confidence**: high
- **Tags**: full-duplex, multi-party, dataset, benchmark, long-context
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-003>

Extends the Moshi paradigm to long-horizon, multi-party English-Chinese full-duplex dialogue. Releases 57.6k hours of synthetic training data (MultiTalkPT, MultiTalkFT) with controllable participant count, overlap, backchannels, interruptions and addressee shifts, plus MultiTalkBench, built from real recordings averaging 32.6 minutes. The authors' bilingual model substantially outperforms Moshi, MiniCPM-o-4.5 and Qwen3-Omni-30B-A3B-Instruct on MultiTalkBench; the abstract gives no single headline number. Accepted at NeurIPS 2026.

**Related**

- Models: [moshi](https://fullduplex.ai/models#moshi)

---

### DuplexAct-Bench: Broadening Full-Duplex Speech Evaluation toward Proactive Interaction across Diverse Behavioral Requirements

- **Type**: paper
- **Source**: arXiv — <https://arxiv.org/abs/2609.39446>
- **Byline**: Xing et al. (BIGAI; Peking University; SJTU X-LANCE)
- **Confidence**: high
- **Tags**: full-duplex, benchmark, backchannel, turn-taking
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-004>

Bilingual benchmark of six full-duplex behaviours (including interruption, yielding, proactive initiation, active silence and backchanneling) under Pre-session, In-session and No-explicit conditions. 1,290 English and Chinese streaming trials score 12 systems on Timing and Content, finding large variation and frequent mismatch between semantic quality and timing. Per-author affiliation mapping is not stated. Fullduplex is published by oto; the No-explicit backchannel subset uses a subset of oto's otoSpeech-full-duplex-280h under CC BY 4.0.

**Related**

- Datasets: [otospeech-fd-280h](https://fullduplex.ai/datasets#otospeech-fd-280h)

---

### AssemblyAI Universal-3.6 Pro Realtime: streaming speech recognition tuned for voice agents

- **Type**: model
- **Source**: lab blog — <https://www.assemblyai.com/blog/universal-3-6-pro-realtime>
- **Byline**: AssemblyAI
- **Confidence**: high
- **Tags**: asr, streaming, voice-agents, endpointing
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-005>

New streaming model universal-3-6-pro at $0.45/hr, 32 languages with automatic language detection. On AssemblyAI's own English voice-agent benchmark (12,460 scripted calls, vendor-reported): WER 5.19% vs Scribe v2 7.78%, Nova-3 8.64%, Flux EN 13.50%; entity error 14.4%. Wrong short confirmations fall from 2.65% to 1.45%. On 2,950 non-speech clips it returns text 0.27% of the time vs 38.75% for Deepgram Flux EN. End-of-turn precision rises from 74.1% to 77.9% at 92.8% recall, with median endpoint latency unchanged at 537 ms.

---

### Microsoft AI releases MAI-Transcribe-2-Streaming, MAI-Voice-2.1 and MAI-Voice-2.1-Flash

- **Type**: model
- **Source**: lab blog — <https://microsoft.ai/news/our-first-streaming-transcription-model/>
- **Byline**: Microsoft AI
- **Confidence**: high
- **Tags**: asr, tts, streaming, voice-agents
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-006>

MAI-Transcribe-2-Streaming: 60 languages, continuous automatic language detection, first partials in just over 100 ms, introductory $0.54/hr through year end. MAI-Voice-2.1: 23 languages and 26 locales with one voice across languages, $22 per 1M characters. MAI-Voice-2.1-Flash: 150 ms end-to-end latency, $15 per 1M characters. All figures vendor-reported; API only, no weights. Available through Microsoft Foundry and Azure Voice Live.

---

### ElevenLabs Eleven v4 and Eleven v4 Turbo text-to-speech

- **Type**: model
- **Source**: lab blog — <https://elevenlabs.io/blog/eleven-v4>
- **Byline**: ElevenLabs
- **Confidence**: high
- **Tags**: tts, latency, voice-agents, multilingual
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-007>

New TTS family: eleven_v4 on the Text to Dialogue API and eleven_v4_turbo on the Text to Dialogue WebSocket, in ElevenAgents and the API. Vendor-reported: ranked #1 by Artificial Analysis, preferred by about 75% of listeners in blind tests against competing models; Turbo has about 100 ms median inference latency and about 150 ms median time to first speech. 90+ languages, instant voice cloning from 10 s of audio, inline audio tags. Turbo uses a different endpoint from the classic TTS stream.

**Related**

- Models: [elevenlabs-agents](https://fullduplex.ai/models#elevenlabs-agents)

---

### Tavus Griffin-Lite: research preview of a full-duplex video-to-video conversation model

- **Type**: model
- **Source**: lab blog — <https://www.tavus.io/griffin>
- **Byline**: Tavus
- **Confidence**: medium
- **Tags**: full-duplex, video, avatar, turn-taking, preview
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-008>

Tavus's first Human Interaction Model: one real-time system that takes in a caller's audio and video, decides every sub-second mini-turn whether to speak, react or wait, and streams 720p video in 320 ms chunks. Vendor-reported: 0.43 s audio-to-video latency on H100s, and 26 of 54 participants (48%) took it for a real person after a one-minute call, vs 1 of 41 for the previous stack. NVIDIA's VideoFDB leaderboard (0 to 5): generation 3.83 (human 3.92), perception 3.73 (human 4.20), median response 1,892 and 2,232 ms (human 900 and 1,400 ms).

**Related**

- Models: [tavus-griffin-lite](https://fullduplex.ai/models#tavus-griffin-lite)

---

### Index-Echo-S2ST: open speech-to-speech dubbing that keeps the source speaker's voice

- **Type**: model
- **Source**: Hugging Face — <https://huggingface.co/IndexTeam/Index-Echo-S2ST-9B>
- **Byline**: IndexTeam (bilibili)
- **Confidence**: medium
- **Tags**: speech-translation, speech-to-speech, dubbing, open-weights
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-009>

Speech-to-speech translation that keeps the source speaker's voice: Chinese or English in, English, Spanish, Japanese or Chinese out. A frozen Index-Echo-S2TT backbone feeds a learned Hidden2CV mapper and CosyVoice3, trained with differentiable reward optimization. Apache-2.0, 9B and 2B, plus S2TT siblings; technical report arXiv:2609.40181. Vendor-reported: against a matched S2TT plus CosyVoice3 pipeline on in-house dubbing data, the 9B lowers mean content error in four of six directions; Chinese to English favours the pipeline. Traction is still small (15 likes).

---

### Hume is sunsetting its TTS and EVI APIs on November 13, 2026

- **Type**: reclassified
- **Source**: lab blog — <https://dev.hume.ai/changelog>
- **Byline**: Hume AI
- **Confidence**: high
- **Tags**: deprecation, speech-to-speech, tts, voice-agents
- **Verified**: 2026-10-05
- **Permalink**: <https://fullduplex.ai/signals/2026-W41#2026-w41-010>

Hume's developer changelog, dated October 2, 2026, says it is sunsetting the TTS and EVI (Empathic Voice Interface) APIs. Access ends November 13, 2026 at 12:01 a.m. EST, both APIs stay supported until then, and account data is permanently deleted afterwards. No reason is given. EVI should be tracked as end-of-life; teams using it for emotion-aware speech-to-speech need a replacement before mid-November.

**Related**

- Models: [hume-evi-3](https://fullduplex.ai/models#hume-evi-3)