The Mind Creative OCTOBER 2013 | Page 40

The Mind Creative OCT 2013 SUGGESTED EXPLANATIONS Tinnitus, a disturbance of the auditory system, has been used to explain the Hum. However, this does not explain as to why the Hum can be heard only at certain geographical locations. Those who suffer both from tinnitus and hear the Hum, describe them as qualitatively different and many hum sufferers can find locations where they do not hear the hum at all. Colliding ocean waves Researchers from the USArray Earthscope have tracked down a series of infrasonic humming noises produced by waves crashing together and thence into the ocean floor, off the North-West coast of the USA. Potentially, sound from these collisions could travel to many parts of the globe. Spontaneous Otoacoustic Emissions This term refers to the condition where the ear generates its own noises. Recordings of sounds that appear to be the Hum, such as that made in Auckland, would indicate that this suggested explanation cannot explain all occurrences of the Hum. Mechanical devices In the case of Kokomo, Indiana, a city with heavy industries, the origin of the hum was thought to have been traced to two mechanical sources. After those devices were corrected, the hum still persisted. Geoff Leventhall, the eminent acoustics expert, has recommended that some hearers should turn to cognitive-behavioural therapy to relieve the symptoms caused by the Hum. He is however, not confident that this intriguing phenomenon, that has been a mystery for 40 years, will be solved anytime soon. 40