Answer:
It is a sound of empty, speak and it'll talk back plenty. But all the more you yack, you'll get the same words back.
A hole in a pole, though I fill a hole in white. I'm used more by the day, and less by the night.
Never alive but practically extinct. How we miss the letters pressing the ribbon of ink. What is it?
Glittering points that downward thrust. Sparkling spears that never rust.
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
What sphinxes employ and players enjoy.