Glossary

Lip-sync

Lip-sync is the process of matching translated dialogue or AI voiceover precisely to the lip movements of the on-screen speaker. It’s used in film, television, eLearning content and marketing to make dubbed or localized content appear natural and authentic.

Description

Lip-sync – short for lip synchronization – aligns translated speech with the original speaker’s mouth movements and timing. The goal is to ensure that audiences perceive the localized version as seamless and emotionally consistent with the source.

In a typical lip-sync workflow, linguists adapt the translated script for rhythm, timing and natural phrasing, while voice actors record new audio that fits both the translated dialogue and the on-screen performance. Engineers then adjust pacing and alignment in post-production. In AI dubbing workflows, advanced speech synthesis and alignment models automatically match timing and mouth movement across languages, creating faster and more scalable lip-sync output. Human review ensures that tone, performance and cultural nuance remain faithful to the original.

Example use cases

  • Entertainment: Localize films, series and animation for multilingual audiences.
  • Corporate: Produce training content and onboarding materials that feel natural and engaging.
  • Marketing: Adapt product demos or advertisements for international markets.
  • Multimedia: Combine automation with human direction for large-scale video projects.
  • Accessibility: Support inclusive experiences by aligning multilingual voice and visuals.

Key benefits

Authenticity
Maintains natural rhythm and emotional tone across languages.
Immersion
Helps audiences connect with characters or speakers more intuitively.
Efficiency
Reduces production time through hybrid AI + human workflows.
Scalability
Supports high-volume, multilingual video localization projects.
Scalability
Ensures lip and sound alignment meet broadcast and brand standards.

RWS perspective

At RWS, lip-sync is where creativity meets precision. Within our Video and Audio Translation services – including AI dubbing and AI voiceover – we combine linguistic expertise, performance direction and intelligent automation to deliver culturally authentic results.

Our Human + Technology approach ensures that every lip-synced video balances emotion, clarity and timing. AI-assisted lip-syncing accelerates production, while human artists refine delivery, emotion and tone for natural resonance. From marketing campaigns and eLearning to entertainment and explainer videos, RWS helps organizations speak fluently on screen – making every localized message look and sound right.