Ya, the new audio engine “V2” went live this week, and we issued a breaking change notification a few weeks ago to announce the disabling of the old audio engine by default instead of enabling it by default when the graphics Engine is created.
The playground automatically enables the old audio engine when it is used, so no change should be needed for new or existing playgrounds.
In your own code you’ll need to set the Engine constructor’s audioEngine option to true to enable the old audio engine, for example:
var engine = BABYLON.Engine(canvas, true, { audioEngine: true }, true);