---
id: "2025-07-24-bytedance-seed-liveinterpret-2"
url: "https://postcutoff.com/e/2025-07-24-bytedance-seed-liveinterpret-2/"
as_of: "2026-11-13T13:49:00+01:00"
date: "2025-07-24"
date_precision: day
category: model-release
importance: 3
confidence: high
status: [Confirmed]
sources: 3
editor: human editor
human_review: null
version: "2026-10-07"
---

As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/e/2025-07-24-bytedance-seed-liveinterpret-2/

# ByteDance's LiveInterpret 2.0 interprets Chinese-English simultaneously in your own voice

Full title: ByteDance Seed LiveInterpret 2.0: end-to-end Chinese-English simultaneous interpretation in your own voice, ~3 s behind

On 2025-07-24 ByteDance's Seed team released Seed LiveInterpret 2.0, an end-to-end speech-to-speech simultaneous interpretation model for Chinese<->English that speaks the translation in the speaker's cloned voice about 2.5-3 s behind. In ByteDance's human evaluations it came close to professional interpreters and far ahead of other systems. It shipped on Volcano Engine as "Doubao - Simultaneous Interpretation 2.0".

## Key facts
- Latency: ~2.21 s first-word (speech-to-text) and ~2.53 s (speech-to-speech), which ByteDance says is 60-70% lower than cascaded systems (down from nearly 10 s)
- Accuracy: >70% in multi-speaker and >80% in single-speaker settings; human-eval score 74.8/100 (speech-to-text) vs 47.3 for the runner-up baseline; 66.3/100 speech-to-speech
- Real-time zero-shot voice cloning of each speaker; large-scale pretraining plus reinforcement learning to trade accuracy against latency
- Paper: arXiv 2507.17527 'Seed LiveInterpret 2.0: End-to-end Simultaneous Speech-to-speech Translation with Your Voice'
- Available on Volcano Engine (Ark console, 'Doubao - Simultaneous Interpretation 2.0'); planned for ByteDance's Ola Friend earbuds from end of Aug 2025. Public API model id and pricing not verified

## What happened

ByteDance replaced the usual ASR -> MT -> TTS cascade with a single end-to-end model that listens, translates and speaks
at the same time, and renders each speaker's translation in their own cloned voice.

## Why it matters

It was one of the first product-grade end-to-end simultaneous interpreters. It came roughly ten months before OpenAI's
gpt-realtime-translate (May 2026), Google's Gemini 3.5 Live Translate (June 2026) and Alibaba's Qwen3.8-LiveTranslate
(Sept 2026). All accuracy figures are ByteDance's own evaluations. It covers only Chinese and English.

## Your AI and this story

- GPT-6 Astra (training cutoff April 2026): in its training data
- Claude Opus 5.5 (training cutoff June 2026): in its training data
- Gemini 4 Hydrogen (training cutoff March 2026): in its training data
- Grok 4.7 (training cutoff May 2026): in its training data

## Sources

1. [ByteDance Seed blog - Seed LiveInterpret 2.0 released](https://seed.bytedance.com/en/blog/seed-liveinterpret-2-0-released-an-end-to-end-simultaneous-interpretation-model-featuring-ultra-high-accuracy-close-to-human-interpreters-low-latency-of-3-seconds-and-real-time-voice-cloning) (seed.bytedance.com, official)
2. [arXiv 2507.17527 - Seed LiveInterpret 2.0 technical report](https://arxiv.org/abs/2507.17527) (arxiv.org, paper)
3. [Volcano Engine console - simultaneous interpretation demo](https://console.volcengine.com/ark/region:ark+cn-beijing/experience/voice?type=SI) (console.volcengine.com, docs)

## Changes

- 2026-09-29 (filed): Created

## Related

- 2026-08-05: [ByteDance deploys SeedRealtime, a native audio-visual full-duplex model, in the Doubao app](https://postcutoff.com/e/2026-08-05-bytedance-seedrealtime/index.md)
- 2026-06-09: [Google launches Gemini 3.5 Live Translate, voice-preserving real-time speech translation in 70+ languages](https://postcutoff.com/e/2026-06-09-gemini-3-5-live-translate/index.md)
- 2026-05-07: [OpenAI releases GPT-Realtime-2, GPT-Realtime-Translate and GPT-Realtime-Whisper](https://postcutoff.com/e/2026-05-07-openai-gpt-realtime-2-translate-whisper/index.md)