realsi-sst-eval
Seed LiveInterpret 2.0: End-to-end Simultaneous Speech-to-speech Translation with Your Voice — Cheng et al. (2025) (arXiv:2507.17527, 2025)
What this evaluates
Evaluates end-to-end simultaneous speech-to-speech translation quality and latency on long-form, multi-domain continuous speech. Probes the model's ability to maintain semantic accuracy, speaker voice characteristics, and low delay in real-time multilingual dialogue.
Datasets
- RealSI — total ?; splits: test (-1)
Metrics
VIP (primary) — range: [0, 100] (score)
- Human evaluation metric measuring the proportion of valid semantic fragments that accurately convey the speaker’s original intent, closely aligning with human interpreter judgments.
SVIP — range: [0, 100] (score)
- Speech-specific extension of VIP measuring the proportion of valid speech semantic fragments within a session, requiring core information accuracy, acceptable latency, appropriate pace, and acoustic clarity.
BLEURT — range: [0, 100] or [-1, 1]
- Automated neural metric for translation quality based on BERT representations.
COMET — range: [0, 100] or [-1, 1]
- Automated neural metric for translation quality using cross-lingual representations.
FLAL — range: [0, ∞) seconds
- First Letter Appearance Lagging: time until the system outputs the first determined translation at the paragraph level.
AL — range: [0, ∞) seconds
- Average Lagging: widely adopted sentence-level latency metric measuring average delay between source and target utterances.
LAAL — range: [0, ∞) seconds
- Length Adaptive Average Lagging: sentence-level latency metric normalized by output length.
Input / output format
Input: Continuous audio speech in Chinese or English (approx. 5 minutes per sample for long-form; sentence-level for short-form).
Output: Translated audio speech in the target language (with voice cloning) or translated text, generated simultaneously as the source audio plays.
Scoring recipe
def calculate_vip_svip(transcript_segments):
valid = 0
total = len(transcript_segments)
for seg in transcript_segments:
if (conveys_core_intent(seg) and
latency_acceptable(seg) and
pace_acceptable(seg) and
clarity_acceptable(seg)):
valid += 1
return (valid / total) * 100
def calculate_latency(source_timestamps, target_timestamps):
al = mean(target_timestamps - source_timestamps)
flal = target_timestamps[0] - source_timestamps[0]
return al, flal
Common pitfalls
- Automated metrics like BLEURT and COMET may not fully reflect true translation capabilities compared to human VIP/SVIP scores.
- Commercial baselines often employ post-hoc rewriting strategies, making direct latency/quality comparisons with human-like simultaneous interpreters misleading.
- Missing table entries indicate lack of feature support (e.g., speech-to-speech) rather than zero performance.
Evidence (verbatim from paper)
For text translation quality assessment, we primarily rely on the idea of the human evaluation metric, Valid Information Proportion (VIP) [[6]], which measures how accurately the translation output conveys the speaker’s original intent for each semantic fragment, closely aligning with human interpreter judgments.
Citation
@misc{cheng2025seedliveinterpret2,
title={Seed LiveInterpret 2.0: End-to-end Simultaneous Speech-to-speech Translation with Your Voice},
author={Cheng et al. (2025)},
year={2025},
note={arXiv:2507.17527}
}
1---2name: realsi-sst-eval3description: Evaluates end-to-end simultaneous speech-to-speech translation quality and latency on long-form, multi-domain continuous speech. Probes the model's ability to maintain semantic accuracy, speaker voice characteristics, and low delay in real-time multilingual dialogue. Use when the user wants to benchmark on RealSI, or asks about evaluating this task. Reports VIP.4---56# realsi-sst-eval78> Seed LiveInterpret 2.0: End-to-end Simultaneous Speech-to-speech Translation with Your Voice — Cheng et al. (2025) (arXiv:2507.17527, 2025)910## What this evaluates1112Evaluates end-to-end simultaneous speech-to-speech translation quality and latency on long-form, multi-domain continuous speech. Probes the model's ability to maintain semantic accuracy, speaker voice characteristics, and low delay in real-time multilingual dialogue.1314## Datasets1516- **RealSI** — total ?; splits: test (-1)1718## Metrics1920- `VIP` **(primary)** — range: [0, 100] (score)21 - Human evaluation metric measuring the proportion of valid semantic fragments that accurately convey the speaker’s original intent, closely aligning with human interpreter judgments.22- `SVIP` — range: [0, 100] (score)23 - Speech-specific extension of VIP measuring the proportion of valid speech semantic fragments within a session, requiring core information accuracy, acceptable latency, appropriate pace, and acoustic clarity.24- `BLEURT` — range: [0, 100] or [-1, 1]25 - Automated neural metric for translation quality based on BERT representations.26- `COMET` — range: [0, 100] or [-1, 1]27 - Automated neural metric for translation quality using cross-lingual representations.28- `FLAL` — range: [0, ∞) seconds29 - First Letter Appearance Lagging: time until the system outputs the first determined translation at the paragraph level.30- `AL` — range: [0, ∞) seconds31 - Average Lagging: widely adopted sentence-level latency metric measuring average delay between source and target utterances.32- `LAAL` — range: [0, ∞) seconds33 - Length Adaptive Average Lagging: sentence-level latency metric normalized by output length.3435## Input / output format3637**Input**: Continuous audio speech in Chinese or English (approx. 5 minutes per sample for long-form; sentence-level for short-form).3839**Output**: Translated audio speech in the target language (with voice cloning) or translated text, generated simultaneously as the source audio plays.4041## Scoring recipe4243```python44def calculate_vip_svip(transcript_segments):45 valid = 046 total = len(transcript_segments)47 for seg in transcript_segments:48 if (conveys_core_intent(seg) and49 latency_acceptable(seg) and50 pace_acceptable(seg) and51 clarity_acceptable(seg)):52 valid += 153 return (valid / total) * 1005455def calculate_latency(source_timestamps, target_timestamps):56 al = mean(target_timestamps - source_timestamps)57 flal = target_timestamps[0] - source_timestamps[0]58 return al, flal59```6061## Common pitfalls6263- Automated metrics like BLEURT and COMET may not fully reflect true translation capabilities compared to human VIP/SVIP scores.64- Commercial baselines often employ post-hoc rewriting strategies, making direct latency/quality comparisons with human-like simultaneous interpreters misleading.65- Missing table entries indicate lack of feature support (e.g., speech-to-speech) rather than zero performance.6667## Evidence (verbatim from paper)6869> For text translation quality assessment, we primarily rely on the idea of the human evaluation metric, Valid Information Proportion (VIP) *[[6]]*, which measures how accurately the translation output conveys the speaker’s original intent for each semantic fragment, closely aligning with human interpreter judgments.7071## Citation7273```bibtex74@misc{cheng2025seedliveinterpret2,75 title={Seed LiveInterpret 2.0: End-to-end Simultaneous Speech-to-speech Translation with Your Voice},76 author={Cheng et al. (2025)},77 year={2025},78 note={arXiv:2507.17527}79}80```8182- arXiv: 2507.17527