Datatable loaded does not work

I'm trying to add a loaded gif in my datatable . I tried but it does not work. Here my code

 <script>
          // Call the dataTables jQuery plugin
          $(document).ready(function() {
              var table = $('#dataTable').DataTable({

                  "destroy": true,
                  "ajax": {
                      "method": "POST",
                      "url": "include/personalJSON.php"
                  },
                  "order": [
                      [0, "desc"]
                  ],
                  "columns": [{
                      "data": "Codigo"
                  }, {
                      "data": "Nombre"
                  }, {
                      "data": "Rut"
                  }, {
                      "data": "FechaIngreso"
                  }, {
                      "data": "DescArea"
                  }, {
                      "data": "Cargo"
                  }, {
                      "data": "Correo"
                  }, {
                    "data": null,
                    "defaultContent": " <button type='button' title='Cambiar contraseña' class='change btn btn-warning' data-toggle='modal' data-target='#myModalthree'  ><i class='fa fa-key' aria-hidden='true'></i>  </i></button>"

                  }],

                  "language": idioma_espanol,

                   "processing": "<img style='width:50px; height:50px;' src='asset/images/Gear-1s-200px.gif'/>"
              });

          });




          var idioma_espanol = {
              "sProcessing": "Procesando...",
              "sLengthMenu": "Mostrar _MENU_ registros",
              "sZeroRecords": "No se encontraron resultados",
              "sEmptyTable": "Ningún dato disponible en esta tabla",
              "sInfo": "Mostrando registros del _START_ al _END_ de un total de _TOTAL_ registros",
              "sInfoEmpty": "Mostrando registros del 0 al 0 de un total de 0 registros",
              "sInfoFiltered": "(filtrado de un total de _MAX_ registros)",
              "sInfoPostFix": "",
              "sSearch": "Buscar:",
              "sUrl": "",
              "sInfoThousands": ",",
              "sLoadingRecords": "Cargando...",
              "oPaginate": {
                  "sFirst": "Primero",
                  "sLast": "Último",
                  "sNext": "Siguiente",
                  "sPrevious": "Anterior"
              },
              "oAria": {
                  "sSortAscending": ": Activar para ordenar la columna de manera ascendente",
                  "sSortDescending": ": Activar para ordenar la columna de manera descendente"
              }
          }
      </script>

HTML

<table class="table table-striped" id="dataTable" width="100%" cellspacing="0">
   <thead>
      <tr>
         <th>Codigo</th>
         <th>Nombre</th>
         <th>Rut</th>
         <th>F.Ingreso</th>
         <th>Area</th>
         <th>Centro Costo</th>
         <th>Cargo</th>
         <th>Correo</th>
         <th></th>
    </tr>
    </thead>
    <tbody>

    </tbody>