I've been working on a new onboarding flow for my team's SaaS product, and I wanted to share a recent experiment that turned out really well. We decided to replace the standard text-based tutorial with a guided voiceover, using PlayHT to generate the narration. The goal was to make the initial user experience feel more personal and engaging, but I quickly ran into a common issue: the pacing felt off. The voice would describe a feature, but the user interface highlights or animations wouldn't always sync up perfectly.
That's when I dove into PlayHT's API documentation to look for a solution. I discovered you can inject **SSML markers** (specifically, the `` tag) directly into your text script. These markers get embedded in the generated audio stream, and you can capture their precise timestamps via the API response. This allows you to trigger actions in your app exactly when the voice mentions them.
Here’s a simplified version of the script I used with the markers inserted:
```xml
Welcome to our dashboard. This is your main control center.
To create your first project, click the blue button in the top right.
Once clicked, you'll see the project wizard appear.
```
After calling the PlayHT API, the response includes a JSON array with the marker names and their exact times (in milliseconds) from the start of the audio. I then built a lightweight JavaScript player in our onboarding module that listens for these timecodes.
The integration logic in our app looks something like this:
```javascript
async function playOnboardingAudio(audioUrl, markerData) {
const audio = new Audio(audioUrl);
markerData.forEach(marker => {
audio.addEventListener('timeupdate', () => {
if (Math.floor(audio.currentTime * 1000) === marker.time) {
// Dispatch a custom event or call a function to trigger the UI update
document.dispatchEvent(new CustomEvent('onboarding-marker', { detail: marker.name }));
}
});
});
audio.play();
}
```
On the frontend, listeners for events like `onboarding-marker` will then highlight specific UI elements, trigger subtle animations, or advance a visual step-by-step guide. The result is a perfectly synchronized, multi-sensory walkthrough that feels incredibly polished.
The main benefits I've observed from this approach are:
* **Dramatically improved user comprehension**, as users hear about a feature and see it emphasized simultaneously.
* **Flexibility to update the script** without re-recording anything—just change the text and markers, and the sync data is regenerated.
* **It's API-driven and automatable**, meaning we can potentially generate slightly personalized onboarding flows based on user role or signup source in the future.
It did require a bit more upfront development work compared to just dropping in an MP3, but the payoff in user engagement has been significant. Has anyone else tried using SSML markers with PlayHT for interactive audio experiences? I'm curious if you've found other creative applications for this feature, especially in automated training or interactive video content.
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