Voice quality and lip-sync are now good enough to publish. Terminology, numbers, names and anything with legal weight are where an unreviewed pipeline will fail while sounding perfectly fluent.
Take the strengths first, because they are real. Cloned voices carry the original speaker's character across languages convincingly enough that a viewer who does not know will not notice. Lip-sync models handle the visual mismatch well for talking-head content, which is most training and explainer video. Timing alignment keeps the dub inside the original cut, so you do not have to re-edit for each language. For a large functional library this is transformative.
Now the failures, which share a characteristic: they are fluent. A machine translation will render your product name Flow as a common noun and produce a sentence that reads perfectly while naming nothing. It will convert lakh and crore into millions when the audience thinks in lakhs, or leave them when the audience does not. It will handle a date as month-day when the market reads day-month. It will soften a compliance disclaimer into something that no longer says what your legal team approved.
None of these produce an obviously broken output — they produce a smooth one that is wrong, which is far more dangerous. The controls are a locked terminology glossary applied before translation, a do-not-translate list for product names and technical terms, explicit locale rules for numbers, dates and currency, and mandatory human review on any segment carrying a claim, a price, a legal statement or a safety instruction. Everything else can flow through with a lighter check.
- Voice cloning and lip-sync are publishable quality for talking-head content today
- Machine translation fails fluently — the output sounds right while meaning something else
- Locked glossary and do-not-translate list for product names and technical terms
- Explicit locale rules for numbers, dates, currency, lakh and crore conventions
- Mandatory human review on claims, prices, legal statements and safety instructions