Audio Optimizations

Maximum number of audios that can run in parallel

All devices have an inherent limitation on the number of audio/video streams they can run in parallel.
No of parallel audio streams
Androids Phones
iOS Phones

Audio AutoStart limitations

If you feel there's no audio in Mobile, but there in the Desktop version - it's probably because Mobile devices are strict about getting a user interaction before allowing audio to play. For this you need to either
  • Enable "Click to start" in project settings.
  • OR start audio only after the user clicks on something in the experience (like a banner/ text or a play icon)
If you want to control this behaviour separately for mobile vs desktop, you can use a variable device_var to check if the user is on mobile and then create Rules to make the experience behave differently for mobile vs desktop access.

Restriction on the number of Audio elements in a scene

There is a hard limit on the number of Audio elements (including both Audio and TTS elements) that can be added in a single scene. Currently, this limit is set to 60 to ensure that no overloading occurs when the experience is played on low-end devices.
There are 2 approaches to work around this restriction:
  1. 1.
    Re-use the same audio element to play different parts of the audio at different instances using the "play from" event.
  2. 2.
    Break the scene down into multiple scenes such that the total number of Audio elements doesn't go beyond 60 per scene.

Audio on iOS Devices

iOS (iPhone) devices don't support volume controls. This has two implications:
  1. 1.
    No volume control icon on top of the experience in iOS devices.
  2. 2.
    Volume control rules don't work in iOS devices.

Optimize Audio File Size

All audio files get downloaded completely at the start of scene. So try keeping size of the audio files low. Recommended file size for audio elements: less than 2MB