Voice search with 'x-webkit-speech' attribute

Good time, dear module developers! Great Thanks for this module!

Firstly sorry for my bad English!

I tried to add 'x-webkit-speech' attribute in the <input>, but my code knowledge is so bad as my English. :)

Please, how to add this attribute in my module or may be my code is not so absurd:

<?php
function my_google_ajax_search_google_ajax_search_form(&$form_state) {
  $form[$form_id]['search'] = array(
    '#attributes' => array('x-webkit-speech' => ''),
  );
}

In html at all it should be so: <input x-webkit-speech="x-webkit-speech" [all_other_attr's]>.