The Hum HUM vertical component, By Dr Chris Barnes, Bangor Scientific and Educational Consultants, Bangor, Gwynedd, Wales, UK E-MAIL manager@bsec-wales.co.uk

 

Introduction

 

The HUM is enigmatic and anomalous sound (possibly infrasonic) heard throughout the world. As far as I am aware researchers have been unable to source the HUM or even point effectively towards its direction.

 

It is known however, that the HUM is perceived louder in houses and stationary vehicles. This has often been put down to the fact that these enclosures provide masking from external noise.

 

An alternative proposal would be that the HUM has a strong vertical component which forces these structures and /or the air column within into vertical pressure oscillation.

 

Some simple experiments have been performed which would strongly appear to confirm this hypothesis.

 

Experimental work

 

1. Based on the notion that the HUM may have acoustic or vibration components in yet not withstanding the possibility of individual; sensitisation to the HUM by other force fields, an experiment was devised to try to directionally amplify the HUM.

 

 

The apparatus used was essentially very primitive but highly effective. The lid of garden refuse incinerator was employed as a sort of giant ear trumpet!

 

 

Placing the narrow end of the lid to the ear would be expected to cause a focussing effect for sound waves in the vicinity of the user.

 

Whilst experiencing a particularly strong episode of the HUM on the evening of Tuesday July 17th at circa 2300 hours and the morning of July 18that 0800 hoursthe author placed the narrow end of the lid first to his left ear and then to his right and proceeded to walk in a tight 360 degree turn.Then with the lid to his right ear the author turned so this ear faced the ground. The experiment was performed in a small downstairs room with all sound sources in the house switched off.

 

 

 

The lid was also subsequently placed on the floor broadside down and the author placed his right ear about 1 cm above the narrow end.

 

2.     Standing waves

If the Hum†† component was horizontal it should be possible to detect standing waves

by walking to various locations in large rooms. Slight nodes and antinodes could be detected by the unaided ear on the ground floorof the author's premises, corresponding to a room resonance of about 28 Hzbut not the second floor.††

 

Results

 

Placing the lid to left ear made no impact on the HUM level whatsoever. No directivity in the HUM could be discerned. Placing the lid on the right ear actually reduced the HUM level slightly whilst standing normally and rotating, yet sounds of other kinds such as vehicular and people noise outside the house could be heard clearly amplified with expected directivity. Only in the downward direction the HUM level was noted to increase significantly.

 

 

With the lid placed on the floor as described above a very significant increase in HUM level could be discerned but only with the authorís right ear about 1 cm above the open end.Clearly the air column above the lid needed to move to and fro.

 

 

Discussionand Conclusions

 

 

These simple experiments prove that the HUM has a significant vertical component.

There may be some horizontal component at ground floor level.These finding could be explained if the Hum†† was diffracted into premises at steep angles from above or below and/or if the Humhas more than one component which has proved to be a previous pre-requisite. Given the height of the house and the fact that it has a chimney

a†† vertical Helmoltz resonance as low as 9.4 Hz may be possible.