sounds duplicate

Dear All

Im trying to play once a sound but every time the override the sound chanel duplicate. Also Im trying to sop the sound when its no visilbe but donesnt work

could some help me please....

package
{

    import flash.events.Event;
    import org.papervision3d.objects.parsers.DAE;
    import flash.display.Sprite;
    import flash.events.*;
    import flash.display.BitmapData;
    import flash.display.Loader;
    import flash.net.URLRequest;
    import flash.media.Video;

    import flash.media.Camera;
    import flash.events.KeyboardEvent;
    import flash.sampler.NewObjectSample;
   
   
    import org.papervision3d.objects.parsers.DAE;
    import org.papervision3d.materials.VideoStreamMaterial;
    import org.papervision3d.materials.MovieMaterial;
    import org.papervision3d.materials.BitmapFileMaterial;
    import org.papervision3d.materials.VideoStreamMaterial;
    import org.papervision3d.materials.utils.MaterialsList;
    import org.papervision3d.objects.primitives.Plane;
    import org.libspark.flartoolkit.core.rasterreader.IFLARBufferReader;

    import flash.net.URLRequest;
    import flash.media.Sound;
    import flash.media.SoundLoaderContext;
    import flash.media.SoundChannel;
    import org.papervision3d.core.data.UserData;
    import flash.sampler.pauseSampling;

    public class copihue extends PV3DARApp
    {

        private var copihue:DAE;
        private var quality:uint = 1;
       
       
        public function copihue()
        {
            this.init('Data/camera_para.dat', 'Data/copihue.pat');
        }

        protected override function onInit():void
        {
            super.onInit();

            this.copihue = new DAE(true,null,true);
            this.copihue.load('model/copihue/copihue.dae');
            this.copihue.scale = 0.50;
            this.copihue.x = 0;
            this.copihue.y = 0;
            this.copihue.rotationX = -90;
            this._baseNode.addChild(this._copihue);

            function metaDataHandler(infoObject:Object):void
            {
                trace('metaDataHandler',infoObject);
            }
        }

       
       
        public override function _onEnterFrame(e:Event = null):void
        {
            super._onEnterFrame(e);
            if (this._baseNode.visible)
            {
            var sonido1:Sound = new Sound(new URLRequest("copihue.mp3"));
            var canal:SoundChannel = sonido1.play();
  
            }
            else
            {
                sonido1.stop();
          
            }
        }

    
    }
}