The only places I've been experiencing absolute silence interrupted only by an occasional Chick-a-Dee or woodpeck and the Elk cow that send a surge through you like a bolt out of the blue is 5-8 miles back off the nearest gravel road on BLM land out west in the mountains where it's no motorized vehicles period.
You don't realize how rare silence is, until you've experienced that.
Sometimes no sound at all is priceless.