Completely Optional Knowledge

The podcast where we answer the questions you never knew you had. Produced by Andrew Norton with music by Breakmaster Cylinder.


What Sounds Can't I Hear?

Annie McEwen has great hearing — but she's still only human — so she's wondering what sounds are out there that she's not able to pick up. To find the answer, we spoke to Milton Garces of the University of Hawaii's Infrasound Laboratory. He tells us about the constant din that eludes our futile human ears. Image credit: Flickr user Nickolai Kashirin (


 2016-03-22  9m