What’s the proper way to use the get_image_tag filter?

Thanks to Rarst pointing out that I was in the wrong place, I did some more digging and ended up with this:

add_filter('wp_get_attachment_image_attributes', 'wpse_19029_no_image_title');

function wpse_19029_no_image_title ($attr) 
{
    unset($attr['title']);
    return $attr;
}