Energy damage to Elemental Kin barbarians

[Dave the pom]

The elemental fury ability additional rage rounds does this apply to any type of elemental damage or only a single kind?

Elemental Fury (Ex): At 3rd level, whenever the elemental kin takes an amount of energy damage equal to or greater than her barbarian level while raging, she adds 1 to the total number of rounds that she can rage that day. At 6th level, and every three levels thereafter, the number of extra rounds per energy attack increases by +1, to a maximum of +6 rounds per energy attack at at 18th level.

[nicklas Læssøe]

as it nowhere in the rule you posted, says anything about one specific elemental type, it must therefore be all elements.

If you look under the barbarian elemental resistance rage powers, it specifically says you have to pick an element, and that the bonus only applys to that element, therefore it would be a fair assumption, that they would have written it this time too, if they meant only one element.

from a balance point, i also think the ability would be useless if it really meant only one element type, so i can see no argument for only using it for one specific element.