The Hum, TCAMO full circle, power systems and do we really need space physics interactions for all cases.  By Dr Chris Barnes, Bangor Scientific and Educational Enterprises  Email Web



The Hum is defined. The likely present day and historic causes of the Hum are discussed.  More evidence is put forward for the involvement of power systems in the Hum and the fact that faults , noise and harmonic in the LV network might cause daytime Hum without the need for Space Physics involvement.




The Hum in classic definition is an idling engine type noise occurring geo-sporadically in location and time and perceived by an estimated 2-11% of the population.  For some it is of little concern, for others a cause of occasional sleep disruption and for a few unfortunates they are driven to distraction or on the odd occasion even suicide (



The present author’s exhaustive period of seven years research points almost beyond doubt to the Hum as being a magneto-acoustic effect both in generation and perception and to the increasing power density in World Power Systems (Electricity) as being the most likely present cause based on measurements pertaining to the composition and frequency of occurrence of the so called Bangor Hum. 


Hummers report mainly hearing the Hum at night but some hear it all day long depending on location.  Professor David Demming commented that the original UK Hum of the 1970’s seemed to most likely coincide with the expected positions of TCAMO aircraft in space and time. These transmitted 200 kilowatt VLF transmissions to submarines.  It is thought the TCAMO system may have long since been superseded.


TCAMO ‘full circle’

At the time of Deming’s paper, the present author was unconvinced concerning the possible involvement of TACAMO because other land based VLF sites did not produce the Hum. However, the present author did comment in a letter to JSE that if VLF detection in humans is non-linear, the TCAMO hypothesis could be feasible.  Plus TCAMO would also provide infrasound another component of Hums. Since this letter there is a swelling body of evidence to suggest that electromagnetic bio-effects and magnetic detection in humans is expected to be non –linear (Carrubba et al  and possible at very low field strengths. There has also been confirmed the presence of biogenic magnetite in humans ( Humans are doubtless tuned to natural radio and magnetic processes of the planet and exosphere ( Indeed the author has recently advanced a hypothesis involving PC1 pulsations and seismic mixing to account the Hum. The very fact that human magnetic and electromagnetic sensitivity has been shown to be non –linear could alone (as a separate simpler hypothesis) be sufficient to account for the geo-sporadic nature of the Hum in time and space.    Nowadays HAARP is most likely used for submarine communication along with other uses of ELF and VLF.  Practical research and personal experience of the author tends to suggest that power systems harmonics and ground currents are far more potent prime movers of the Hum.   




Do we need Space Physics?

Based on the behaviour of the Hum at the author’s Bangor residence it would appear that the Hum has anthropogenic and natural components and peaks with outbreaks of PLHR/MLR.  Not only have 50 and 60 Hz line spacing been observed but recently 16.7 Hz spacing due to railway systems has also been found! ELF magnetospheric lines observed by DEMETER
Parrot M., Nemec F., Santolik O., Berthelier J.J.
Annales Geophysicae 23, 10 (2005) 3301-3311 -

PLHR/MLR is thought to arise from direct radiations to space form the HV and EHV power grid.  PLHR/MLR frequencies span up to a few kilohertz i.e. covering the VLF band and there are recognised mechanisms for electrophonic hearing in this band ( ).


However, do we really need PLHR or high voltage for the Hum?  Some Hummers describe hearing the Hum at certain locations all the time. The author is presently in direct personal communication with a lady Hummer in South Wales and two in Charlbury Oxfordshire who fall into this category.  The author has recently noticed ‘daytime’ Hum in his mother’s residence and at two locations between the villages of Tregarth and Mynydd Llandygai in Gwynedd.  All three locations are immediately adjacent to overhead three phase supply in the LV network and all three are very proximal with BT         telecoms conductors as well, the involvement of signals from the latter is unknown. 




Common however, to all three sites are very high levels of noise and harmonic measurable in two of the sites up to 2MHz and at one site up to 14 MHz!!  The cabling is solid conductor type so it is speculation that the noise is partial Insulator breakdown or earth current generated. It should be noted that there is no PLT (BPL) in North Wales. These have been recently advocated for a severe rise in the Hum in the USA. However it is unsure if there could be cross-talk via earth loops or similar between LV power and BT as a precipitator of Hum.   Further studies will be made.

It is hoped to report on a spectral analysis at these sites at a later date.

It is tempting to speculate this   scenario may be yet another generic cause of the Hum.



TCAMO could have had an electromagnetic involvement in the early Hum after all! Space Physics processes and the Super Grid are more than likely involved in night time only cases of the Hum. However, fault conditions on the LV power network might cause localised daytime outbreaks of the Hum. Further work is planned.