To play,stop and pause sound using as3 we have to use following:

flash.media.Sound : Sound class is used to handle the loading and playing a sound. flash.media.SoundChannel: SoundChannel object is used to handle the playback like play,pause and stop sound.

How to load external sound file:

var requestSound:URLRequest = new URLRequest("sound file path"); var sound:Sound = new Sound(req);

Sample application to play,pause and stop sound:

Here three buttons btn,btn1,btn2 is used to play,stop and pause a sound:

package  {

    import flash.display.MovieClip;
    import flash.events.Event;
    import flash.events.MouseEvent; 
    import flash.media.Sound; 
    import flash.net.URLRequest;
    import flash.media.SoundChannel;

    public class Main extends MovieClip {

        private var _snd:Sound;
        private var channel:SoundChannel ;

        private var bool:Boolean = true;

        private var pauseValue:int;
        public function Main() {
            // constructor code
        _snd = new Sound(new URLRequest("your sound file"));

        //channel  = _snd.play();

                btn.addEventListener(MouseEvent.CLICK,playSound);

        btn1.addEventListener(MouseEvent.CLICK,stopSound);

        btn2.addEventListener(MouseEvent.CLICK,pauseSound);


        }

        function playSound(e:MouseEvent)
        { 
         if(bool)
         { 
         channel = _snd.play(pauseValue);

         channel.addEventListener(Event.SOUND_COMPLETE, repeatSound);

          trace("play");
         }
         if(!bool)

         {
                        bool = true;

             channel = _snd.play(pauseValue);
             channel.addEventListener(Event.SOUND_COMPLETE, repeatSound);
         }

        }
        function stopSound(e:MouseEvent)
        {
            trace("stop");

            channel.stop();
        }

        function pauseSound(e:MouseEvent)
        {
             pauseValue = channel.position; 
            channel.stop();
            bool = false;

        }

        function repeatSound(e:Event)
        {  trace("repeat");

            channel = _snd.play();
             channel.addEventListener(Event.SOUND_COMPLETE, repeatSound);
        }
    }

}