air android stagewebview play video without sound !!!

i don't Know why stagewebview play video from ok.ru without sound . everything is ok with other like youtube and daylimotion ...

var rect:Rectangle = new Rectangle(0,0,stage.stageWidth,stage.stageHeight);

var url:String = "https://ok.ru/videoembed/12068062600";

var webview:StageWebView = new StageWebView();

webview.stage = this.stage;

webview.viewPort = rect;

webview.loadURL(url);