Sentioscope

Speech and voice controls, as each vendor documents them

Sora 2: synced audio, with the clock written down

The model page lists video and audio as output and describes generation with synced audio. The guide adds the clock: sixteen or twenty seconds a generation, with an extension adding up to twenty seconds at a time to a total of a hundred and twenty. As of 2026-09-22.

Sixteen or twenty seconds, extended twenty at a timeA generation runs sixteen or twenty seconds, and an extension adds up to twenty more at a time to a total of a hundred and twenty. Each extension is a join, and a join is where a voice can drift.One generationSixteen or twentyseconds, with one ortwo short exchangesinside.Then extendEach extensionUp to twenty secondsmore, added to whatalready exists.RepeatTotal ceilingA hundred and twentyseconds, assembledfrom several joins.
Fig. 1 The published length plus the guidance on exchanges is enough to size a scene on paper, which is the cheapest place to find out a line does not fit.
Sora 2 on audio source, statement by statement. Read from the vendor's model page and prompting guide on 2026-09-22.
What the documentation settlesWhat it leaves to a take
Videos are generated with synced audio, with both listed as outputHow reliably the sync holds once a line runs long
Generations run sixteen or twenty seconds, extendable to a hundred and twenty in totalWhether an extension carries the same voice as the segment before it
A four-second shot holds one or two short exchanges; long speeches are unlikely to syncWhere exactly the alignment stops holding, since only a warning is given

Inclusion rule. Only statements found on the vendor page named in the caption, and only ones bearing on this one field. Nothing here is filled in from generated output. Order. In the order the statements arrive on the vendor's page.

1A published length turns dialogue into arithmetic

Most entries in this register say audio comes out and stop. This one gives a writer both halves of a sum: how long a generation lasts, and roughly how much speech fits inside one. That is enough to size a scene on paper before a call is spent, which is the cheapest place to discover that a line does not fit.

The extension changes the shape of the arithmetic rather than removing it. Twenty seconds at a time to a total of two minutes is a sequence of joins, and every join is a place where a voice can drift, so the length is best read as a budget for a beat rather than for a scene.

2The warning is the closest thing here to a statement about mouths

Saying that long, complex speeches are unlikely to sync is an admission rather than a mechanism, and it is more useful than most mechanisms. It tells a writer to break a speech into exchanges, which is also what the prompting guide asks for when it wants turns alternated.

Read strictly, it is not enough to record lip-sync as documented, so that field stays marked unstated. Read practically, it is the sentence a shot list should be written against.

3The others that make sound while they make the picture

Seven more entries generate audio in the same pass. This is the only one that publishes both a clip length and guidance on how much speech to put in one.

  • Kling AI — with the picture, on video 3.0.
  • LTX Studio — with the picture, and audio to video.
  • MiniMax — with the picture.
  • SceneMixer — with the picture, in the language set for the project.
  • Veo — with the picture.
  • Vidu — with the picture, speech available on its own.
  • Wan 3.0 — with the picture, unless switched off.
  • Audio source
    Described as a media generation model generating videos with synced audio, with video and audio both listed as outputgenerated with the pictureOpenAI, Sora 2 model page / recorded 2026-09-22
  • Shot length a line has to fit
    Generations run 16 or 20 seconds, and an extension adds up to 20 seconds at a time to a total of 120OpenAI, video generation guide / recorded 2026-09-22
  • Dialogue timing against clip length
    A four-second shot is said to accommodate one or two short exchanges and an eight-second clip a few more, with long speeches unlikely to syncOpenAI, Sora 2 prompting guide / recorded 2026-09-22

4Sources

Read from the model page and prompting guide at developers.openai.com on 2026-09-22. The same column across every entry is on audio source; everything this vendor publishes about speech is on Sora 2. What counts as documented is on how read.