They filter out harmonics and beats and other interesting but virtually unexplored areas of speech.

They are part of the Arctic Cordillera and are virtually unexplored.

I had been on the borders of a virtually unexplored land inhabited by dangerous, untouched tribes.

It had been 18 vexing miles from Colliersville, a dicey journey across a railroad spur virtually unexplored since the turn of the century.

Linked with these anchialine pool is a great network of caves and passages, most of them virtually unexplored.

Such ideas, however, are left virtually unexplored in this show, which appears to lack any shaping hand or core thematic approach.

Millions of square miles were virtually unexplored and uncharted.

I knew it was virtually unexplored, a blank on the map which only four thousand years ago had been covered by the glaciers of the last Ice Age.

The island of Puerto Rico was left virtually unexplored, undeveloped, and (excepting coastal outposts) largely unsettled before the 19th century.

The region was virtually unexplored until the 1920s, when exploration for oil brought reports of an un-described volcano.