so you want to hide a section if there are any vouchers in the cart, and a voucher is marked by setting the ShippingType column value to "standard". Is that correct?
you can use the ConditionalTotal function for this:
<?php if($yourCart->ConditionalTotal("Quantity", "ShippingType", "standard") < 1)) { ?>
No vouchers are in the cart
<?php } ?>
where yourCart is the name of your eCart object.