The Guns of Barisal and Anomalous Sound Propagation
- Discussion of research into the physics behind mysterious sounds resembling cannon fire, heard at Barisal, India, and other locations around the world.
- http://www.du.edu/~jcalvert/waves/barisal.htm

Unexplained Sounds
- About.com page gathers together information about mysterious booms, persistent hums, and underground rumblings that defy explanation. Includes audio clips.
- http://paranormal.about.com/library/weekly/aa031599.htm

Hum Forum
- Yahoo Group for discussion of mysterious hums.
- http://groups.yahoo.com/group/humforum/

The Moodus Noises
- Account of the legends and modern accounts of the mysterious sounds heard in Moodus, Connecticut.
- http://www.curbstone.org/index.cfm?webpage=96

The Hum
- Investigation into the cause and adverse health effects of the Bristol Hum, an obnoxious low-frequency noise heard in England. Conclusion is that the hum is due to a pulsed electrical signal.
- http://homepages.tesco.net/~John.Dawes2/

Hum Haunts Indiana City; Its Source Is a Mystery
- New York Times article about a mysterious low-frequency noise reported by residents of Kokomo, IN.
- http://www.nytimes.com/2002/06/23/national/23KOKO.html

Taos Hum Page
- Information and links about the "Taos Hum," a low throbbing sound heard in quiet locations worldwide, especially in the USA, UK, and northern Europe. It is not detectable by microphones or VLF antennae, and the source is still a mystery.
- http://www.eskimo.com/~billb/hum/hum.html

Things That Go Boom in the Night
- Article about the Moodus (Connecticut) noises and the findings of recent investigations that linked these noises with seismic activity.
- http://www.gi.alaska.edu/ScienceForum/ASF8/896.html