Many people who report hearing loud, unexplained booming sounds describe hearing the sounds at night, with the mysterious noises occasionally awakening them from a sound sleep. Often, just as they settle into a light sleep, the experiencer may recall the apparent sound of a crash, explosion, or loud “thud” similar to books hitting the floor, which causes them to jolt awake, often confused or frightened by the noise, or perhaps concern over its seemingly violent source.
With the impressive number of “mystery boom” reports that occur during nighttime and early morning hours, cryoseisms or “frost quakes” have become a popular theory as to their cause, since temperatures will reach their lowest point during these hours. However, there is a very different phenomenon that also coincides with these periods, which not only has experts scratching their heads; it also has many wondering whether the actual cause of some of the booms might reside there, too.
The psychological phenomenon known as “exploding head syndrome” or EHS was, until 2015, a fairly rare variety of hypnagogic auditory hallucination, which, as described above, might meet a number of the criteria for night time “mystery boom” reports. (1) However, unlike the shaking and trembling that some describe feeling in conjunction with the mystery noises, these booms quite clearly seem to originate from within the experiencer’s own head.
Perhaps of equal interest is that some victims of EHS may describe a perceived “flash of light” in conjunction with the phenomenon, (2) which nearly mirrors a number of reports of “mystery booms” which may be caused by upper atmosphere storms. Clearly, there appears to be no correlation between EHS sufferers and the “illuminations” they may perceive, and upper atmosphere storms that may produce flashes of light that coincide with loud booms. However, the similarity between the two, as well as the time of day during which they occur, may certainly be conducive to some confusion among those who think they might have experienced one of the two phenomenon.
It is now believed, following a 2015 study appearing in the Journal of Sleep Research, that as many as 1 in 5 college students may experience the phenomenon, though it is not exclusive to this age group. In fact, the study disputes previous data suggesting that EHS occurs mostly during middle age. (1)
According to Brian Sharpless of Washington State University, author of the study and assistant professor and director of the university psychology clinic, the noise may emanate from what he calls a “momentary neural hiccup as the brain transitions into sleep mode.” (1) Auditory neurons firing simultaneously, rather than shutting down slowly in stages, may be at the root of the phenomenon.
Could a psychological condition like this, even if it occurs more frequently than once thought, actually account for a significant number of “mystery boom” reports? While it is certainly possible that some reports of booms occurring during nighttime hours might fall into this category, daytime booms, as well as those reported where many observers were present at the time of the noise, can easily help rule out a purely psychological basis for the boom reports. The more probable causes, in most instances, are likely to be upper atmospheric weather systems, cryoseisms, and sonic booms produced by aircraft.
- Cohen, Paula. “Exploding head syndrome is real, and surprisingly common.” CBS News, March 31, 2015. http://www.cbsnews.com/news/exploding-head-syndrome-is-real-and-surprisingly-common/
- “Exploding Head Syndrome.” Sleep Association, 2007. https://www.sleepassociation.org/patients-general-public/exploding-head-syndrome/