His approach to the house Number 574 had to be swift, direct, unseen, unheard.
Subtler than sound, and felt, unheard, in the depth of the spirit.
They thought only how to profit by a success so unheard of and so unexpected.
It was a magnificent article, attacking the insurgents with unheard of violence.
There were comforting, unheard, easily dismissable murmurings now and ...