Client Overview
A global e-learning platform serving learners across 60+ countries. Their library includes training modules, expert lectures, and learner support videos.
Challenge: Despite high-quality content, engagement among non-native English speakers was low. Spanish, Hindi, Portuguese, and Arabic learners exhibited higher early drop-off rates, reducing the overall impact of training modules.
Objectives
VerboLabs partnered with the client to provide professional subtitling services:
- Improve multilingual accessibility through high-quality subtitles.
- Accelerate subtitle production while maintaining accuracy using a hybrid AI + human model.
- Increase engagement metrics — watch time, retention, and accessibility adoption.
- Evaluate cost and operational efficiency alongside engagement gains.
Solution — Hybrid Subtitle Workflow
VerboLabs implemented a two-stage subtitling process across the client’s top 400 videos:
Stage 1 — AI-Generated Draft
- Speech-to-text AI created initial English subtitles, then translated them into Spanish, Hindi, Portuguese, and Arabic.
- Draft accuracy ranged 78–85%, depending on language.
Stage 2 — Human Review & Contextual Refinement
- Linguists corrected timing, tone, and cultural phrasing.
- Accessibility ensured proper reading speed, speaker labels, and sound descriptions for hearing-impaired learners.
- Example of AI vs. Human-Refined Translation:
| Language | Raw AI Translation | Human-Refined Translation |
| Spanish | “Ella va a tomar el tren a la escuela a las 8.” | “Tomará el tren local de las 8 AM hacia la escuela.” |
| Hindi | “वह 8 बजे स्कूल जाने के लिए ट्रेन लेगी।” | “वह सुबह 8 बजे की लोकल ट्रेन पकड़कर स्कूल जाएगी।” |
Turnaround Time: Hybrid workflow delivered subtitles 30–40% faster than fully human processes.
Final Accuracy: Post-review, subtitle accuracy was 98–99%, ensuring both linguistic quality and cultural relevance.
Cost & ROI Analysis
| Workflow Type | Avg. Cost per Video Minute | Turnaround Time | Accuracy |
| 100% Human | $4.50/min | 7 days | 99% |
| AI + Human | $3.25/min | 4–5 days | 98–99% |
Insight: The hybrid model delivered ~28% cost savings while increasing speed. Clients could release content faster, engage more learners, and improve ROI without inflating budgets.
Impact Metrics (90 Days Post-Launch)
1. Watch Time Increase
| Language | Avg. Watch Time Before | Avg. Watch Time After | % Increase |
| Spanish | 4 min 20 sec | 6 min 45 sec | +56% |
| Hindi | 3 min 55 sec | 6 min 20 sec | +62% |
| Portuguese | 4 min 05 sec | 6 min 05 sec | +49% |
| Arabic | 3 min 40 sec | 5 min 50 sec | +59% |
| Overall | 4 min 25 sec | 6 min 25 sec | +54% |
Insight: Native-language subtitles significantly improved learner engagement.
2. Accessibility Adoption Metrics
- Subtitle usage grew from 19% to 52% of total views.
- Voluntary subtitle toggles increased from 12% to 37%.
- Learners with hearing impairments interacted with accessible content 1.9x more than before.
Insight: Subtitles became a default viewing mode, not just a fallback option.
3. Global Viewer Retention
| Language | 10% Retention | 50% Retention | 75% Retention |
| Spanish | +13% | +22% | +18% |
| Hindi | +15% | +25% | +20% |
| Portuguese | +12% | +20% | +16% |
| Arabic | +14% | +23% | +19% |
Insight: Contextually refined, culturally accurate subtitles encouraged learners to watch further into videos.
Client Feedback
“VerboLabs didn’t just translate words — they transformed our learner experience. Hybrid subtitles improved both engagement and speed, and the human review ensured cultural relevance. We’re seeing measurable ROI in watch time and learner satisfaction.”
— Director of Content Strategy, E-learning Platform
Key Takeaways
- Hybrid AI + Human Workflows Deliver Efficiency: Faster turnaround, lower costs, high accuracy.
- Cultural and Contextual Refinement Matters: Human review ensures subtitles resonate with learners.
- Accessibility Drives Engagement: Multilingual subtitles increase watch time and retention.
- ROI is Measurable: Cost per minute savings and faster content delivery justify hybrid subtitling.
Conclusion
VerboLabs’ hybrid AI and human subtitling services prove that accessibility, engagement, and efficiency can coexist. By leveraging AI subtitling for speed and human subtitling for accuracy and cultural nuance, clients can deliver multilingual video content that resonates with global audiences. This approach boosts watch time, viewer retention, and accessibility adoption while optimizing production costs.
Ready to make your videos more accessible and engaging worldwide? Explore our Professional Subtitling Services and discover how VerboLabs can help you deliver high-quality, multilingual subtitles that enhance learning, entertainment, and corporate content reach.
Get Started Today — Transform your video content with VerboLabs’ hybrid subtitling expertise.
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