ine component default attributes
      hostAttributes: {
        tabindex: 0,
        role: 'application',
        //'aria-activedescendant': 'play',
        'aria-label': 'Audio Player',
        'aria-describedby': 'title'
      },

      //
      // Define public properties

      properties: {
        src: {
          type: String,
          observer: "_srcChanged"
        },
        title: {
          type: String,
          value: 'Click to play this audio file'
        },
        color: {
          ty