http://stackoverflow.com/q/13769215/922168

gistfile1.js

$.extend($.ui.multiAccordion, {    
  // private helper method that used to show tabs
  _showTab: function($this) {
    var $span = $this.children('span.ui-icon');
    var $div = $this.next();
    var options = this.options;
    $this.removeClass('ui-state-default ui-corner-all').addClass('ui-state-active ui-corner-top');
    $span.removeClass('ui-icon-triangle-1-e').addClass('ui-icon-triangle-1-s');
    // MODIIFICATION
    bindThis = this;
    var ui = {
      tab: $this,
      content: $this.next('div')
    }
    $div.slideDown('fast', function(){
      $div.addClass(options._classes.divActive);
      // MODIFICATION
      bindThis._trigger('tabShownComplete');
    });
    this._trigger('tabShown', null, ui);
  },
  
  // private helper method that used to show tabs 
  _hideTab: function($this) {
    var $span = $this.children('span.ui-icon');
    var $div = $this.next();
    var options = this.options;
    $this.removeClass('ui-state-active ui-corner-top').addClass('ui-state-default ui-corner-all');
    $span.removeClass('ui-icon-triangle-1-s').addClass('ui-icon-triangle-1-e');
    // MODIIFICATION
    bindThis = this;
    var ui = {
      tab: $this,
      content: $this.next('div')
    }
    $div.slideUp('fast', function(){
      $div.removeClass(options._classes.divActive);
      // MODIFICATION
      bindThis._trigger('tabHiddenComplete', null, ui);
    });
    this._trigger('tabHidden', null, ui);
  }
});