counter spell of the Balrog

I see no reason that a counter-spell must entail speaking. It wouldn't be the first time there was a battle of wills in Middle Earth that didn't envolve direct contact. In my mind I see Gandalf preparing for the minds of orcs and coming into contact with the power of a Balrog directed against him. In this context, I think the opposing will could be considered the "counter-spell." Granted this is my personal speculation.