var sound:Sound = new Sound();
var noise:Number = 0;

function sineWavGenerator(event:SampleDataEvent):void 
{
	for(var c:int=0; c<2048; c++) 
	{
		noise += mouseX / 44100;
		var sample:Number = Math.sin(noise * Math.PI * 2);
		event.data.writeFloat(sample);
		event.data.writeFloat(sample);
	}
}
  
sound.addEventListener("sampleData",sineWavGenerator);
sound.play();

New Dynamic Sound

ActionScript 3