Hi,
I suppose that the data will not be the same for all the products, so the easiest way will be to use the custom product fields (commercial version of HikaShop required) then fill the values on the product edition page in backend and finally as Mohamed Thelji said, edit the view "product / listing_img_title" to add code to display the value of the custom field.
Code like:
<?php echo $this->row->CUSTOMFIELD_NAME; ?>
of course CUSTOMFIELD_NAME must be replaced by the name of your custom field.
ps: when we say "product / listing_img_title" that means that via the menu Display > Views you have to click on the file "listing_img_title" of the view "product".