Some thoughts on the Direction of the Hum transmissions.
As yet no direct measurement has been made of the Hum transmissions and the statements made by Hum sufferers are at times ambiguous, however, by collecting a large number of such statements a pattern has emerged which is consistent and fits well with the indirect measurements taken from the walls of buildings.
It is well known that buildings play an important role in the perception of the Hum, but because buildings vary so greatly in size, shape and materials of construction, it is not surprising that observations vary, however, there is a measure of consistency which may be put to use.
It as long been observed that the Hum is louder upstairs than down and this is most evident in multi-storey buildings, especially those which have a basement floor. The upper floors appear to give a measure of protection to those below. As an example, two identically built houses next to each other, one having the roof space converted into an extra room, the Hum level is lower on the ground floor of the house with the conversion. The buildings which produce the highest Hum levels are single storey, with high walls, pointed roofs and have no ceilings, such as old churches. When the Hum is strong enough to be heard outdoors, it is heard at the same strength over very large areas and it is also heard at the same strength on the tops of hills and at the bottom of steep sided valleys. This agrees with the fact that Hum sufferers have found it difficult if not impossible to give a direction from which the Hum is coming, or to locate an epicentre which could be regarded as a source.
Indirect measurements of the Hum signal taken from the walls of a house, show the greatest signal is at the highest part of the walls, just below the eves, also, readings obtained from outward facing walls is much the same which ever way the wall is facing N.S.E.W.
Taking all these observations together, the conclusion reached is that the Hum transmissions enter the building in a vertical direction and for future investigations this will be assumed to be a fact.