Low Frequency Hum

According to newspaper reports coming out of New Zealand, Aucklanders with sensitive hearing are being plagued by a low frequency hum at around 56Hz, toward the lower threshold of human hearing.

• Mystery Humming Sound Captured

• Listen to the sound

You may need to use headphones to hear it, especially if you have a laptop - and some people report that they cannot hear it at all. I can hear it.

According to Wikipedia low pitched humming phenomena have been reported in multiple places around the world beginning in the 1990s, although I can find accounts going back to the late 70s.

• The Hum

A cursory inspection of the web turns up this article about a similar phenomenon in other places:

• Something May Be Fishy About Hum Keeping Bay Ridge Residents Awake (New York)
• Mysterious 'Hum' Harasses Vancouver Residents (Vancouver)
• The Phenomenon of Low Frequency Hums (England)

There is even a Low Frequency Noise Sufferers Helpline in England.

Here is a brief article that I found on the effects of infrasonic (subaudible) sound:

• The Strange World of the Shortwave Number Stations

Here is an interesting Italian-produced documentary on "Star Wars" weapons being trialled in Iraq and Afghanistan (if you can't read Italian, don't worry - just click on the "Play English version" link on the right hand side):

• Guerre stellari in Iraq

To me, the widespread occurrence of humming suggests a common global cause, rather than the kinds of local natural phenomena that are being used to try to explain it away.

Here is a collation of newspaper reports of humming in England spanning 20 years.