Why a Fraction of a Second of Lip Contact Determines Dubbing Success

The Challenge: When a Closed Mouth Clashes with an Open Vowel

The original speaker used many words with the letters p, b and m. These are labial sounds, where the lips must physically meet. In the original French, these lip closures occurred at different times compared to a literal Dutch translation.

If you simply have such a translation read aloud, it immediately creates friction. The viewer sees the speaker close their mouth for a French 'm', while the Dutch voice actor holds an open 'a'. The image and sound clash like a zip whose teeth won't interlock; the whole thing jams. A simple translation is not enough. The sentence structure needs adjustment to match the physical movements of the face on screen.

The Approach: Rewriting Based on Mouth Positions

To solve this, we reworked the translation sentence by sentence, following the editing timeline. We focused not only on the message's meaning, but crucially on the speaker's visual anchor points.

The process involved three targeted steps:

1. Visual analysis: we mapped every moment the original speaker started speaking, stopped breathing, or made a clear lip closure.
2. Rhythmic text editing: we shortened or rephrased sentences so that a Flemish word with a p-, b- or m-sound precisely matched the visible lip movement.
3. Voice selection: we chose an experienced voice actor skilled in lip-sync acting. They could easily adjust to director's instructions.

For this specific production, we looked for a voice with a natural, approachable tone.

The Recording: Guiding on Breathing and Jaw Movement

In the recording studio, timing is everything. Here's a useful director's tip we applied: ask the voice actor to breathe in sync with the person on screen, not just watch the audio waveform. When the voice actor's breathing aligns with the speaker's chest and mouth movements on video, accents and pauses almost naturally fall into place.

During recording, one instruction sentence proved two syllables too long for the on-screen mouth movement. Instead of asking the voice actor to speak faster, we simply removed an unnecessary adverb on the spot. This kept the speaking pace natural and relaxed. The pronunciation finished exactly as the speaker on screen closed their mouth.

The Result: A Natural Illusion

The final video featured Flemish commentary that sat so naturally over the visuals, an outsider wouldn't notice French was ever spoken. Viewers fully focused on the technical training instructions. They were not distracted by misaligned lips or awkward silences.For business and non-commercial productions, like this e-learning, we calculate the rate per word or as a project price. For commercial projects, such as a TV commercial, the fee includes a fixed basic rate for the recording, combined with a buy-out for broadcast rights and usage duration. Clearly understanding the technical requirements of your video beforehand keeps your production on schedule and within budget.

Frequently Asked Questions

What is the difference between regular voice-over and dubbing?

With a standard voice-over, the voice speaks over visuals without needing to match visible mouth movements. With dubbing, the spoken text must synchronise with the mouth movements, breathing, and emotion of the person speaking on screen.

Does the translated text always need to be shorter than the original?

Not always shorter, but it needs to be the same length in speaking time. Dutch generally requires more syllables than English or French. So, sentences often need to be more concise to fit within the same timeframe without the voice actor rushing.

How long does it take to synchronise a voice?

Voice actors must align syllable by syllable with the visuals. This means recording dubbed audio requires more time and preparation than a regular recording. Thorough text preparation beforehand significantly reduces studio time.

Do you want to discuss your video project, or are you unsure about the right approach for your translation? Feel free to contact us for advice on a dubbing voice over that is perfect down to the smallest detail.