We see the world through an extremely limited band of the electromagnetic spectrum. The same goes for our hearing. We consciously process a remarkably tiny proportion of the limited sensory input we receive.
We are only able to measure that which can perceive. And we still don't understand exactly how or why we process anything, other than to facilitate our survival on a purely reptilian level.
The pilot episode of The Outer Limits "The Galaxy Being" (originally titled "Please Stand By") stands along side Star Trek's pilot "The Cage" and the pilot for The X-Files as a definitive statement of intent as well as an indelible blueprint for what was to come.