There are a few ways to introduce a pause or break and influence the rhythm and cadence of the speaker. The most consistent way is programmatically using the syntax `<break time="1.5s" />`. This will create an exact and natural pause in the speech. It is not just added silence between words, but the AI has an actual understanding of this syntax and will add a natural pause.
However, since this is more than just inserted silence, how the AI handles these pauses can vary. As usual, the voice used plays a pivotal role in the output. Some voices, those trained with a few "uh"s and "ah"s in them, have shown to sometimes insert those vocal mannerisms during the pauses, like a real speaker might.
An example could look like this:
"Give me one second to think about it." <break time="1.0s" /> "Yes, that would work."
Break time should be described in seconds, and the AI can handle pauses of up to 3 seconds in length and can be used in Speech Synthesis and via the API. It is not yet available for Projects.
There is one caveat when using SSML breaks; if you use an excessive amount in your text, it might cause issues. The speech of the AI might start speeding up and become very fast, or it might introduce more noise in the audio and a few other strange artifacts. We are working on resolving this.
Alternatives
These options are inconsistent and might not always work. We recommend using the syntax above for consistency.
One trick that seems to provide the most consistence output - sans the above option - is a simple dash `-` or the em-dash `—`. You can even add multiple dashes such as `-- --` for a longer puase.
"It - is - getting late."
Ellipsis `...` can sometimes also work to add a pause between words but usually also adds some "hesitation" or "nervousness" to the voice that might not always fit.
I... yeah, I guess so..."