What is 'The Hum'? While it would be an apt title for a Stephen King novel (your move, Mr. King), it is actually a real-life phenomenon. The Hum is a series of global reports on a low-pitched and distant droning noise that is not heard by everyone. Some experience it locally (only at the grocery store or out back of the Denny's at 3 AM) while others notice it pervasively wherever they go. A key factor of The Hum is that it exists even when obvious sources of sound have been eliminated from the environment. It seems to be more noticeable in rural areas than in the city. People who attempt to counteract The Hum by soundproofing their house have reported that the soundproofing only makes The Hum more prominent. There are numerous hypotheses on what causes the low drone, both internal and external. While some feel the sound is simply the product of tinnitus or possibly the spontaneous sounds the ear makes on occasion., others suspect the origin of the sound is a mechanical device or, in some cases, a biological sound (such as the toadfish) which is just not heard by some people. The phenomenon is well-documented but not well-researched, and it is still a mystery as to why The Hum continues to plague some individuals and not others.