And this is why I think someone should try making recordings in some buildings in the surrounding area. Because I suspect there are tunnels either under the area or nearby and they are acting to funnel sound from various locations. If the same noises can be heard (or recorded) elsewhere, then this may well be the case. Simply recording in one location only doesn't give us any way to triangulate.
Agreed it would be useful.
I suspect that there are other tunnels too.
However, would if follow that if the sounds are only recordable in the basement of my former house, that the source of the noises is either directly under that spot or deep enough not to be heard elsewhere?
We did not record in just one location, most occasions we used four recorders.
I agree with the idea of triangulation, but triangulation does not have to occur on a level field.
As an example, triangulation can be used to calculate depth.
I conducted many experiments before coming to the conclusion that the noises were coming from underneath the basement floor of my former house.
Here are some of the points I used:
The front of the house on both the ground and first floor of the house
The rear of the house in the basement, on the ground floor and on the first floor.
In the very front of the alleyway (the recorder was in the communications box just as you go into the lane)
The rear garden (pointing towards the house).
Out of open windows (pointing towards the bus station at the front and the park at the rear)
In both drains (there are two separate drains in the alleyway)
On the steel lintels inside the property
On all the old exposed lead or other pipes.
Attached to the incoming water pipe.
In the shafts of the two chimneys that service the property
In the loft area (front, middle and rear)
In the old building at the rear of the property
For anyone that is still with me here are some very approx. measurements.
The house is around 4 meters wide and 18 meters long
The old building to the rear is around 4 meters wide and 8 meters long
The rear garden of the property is around 4 meters wide and 6 meters long
The loft area runs from the front of the house to the rear of the house (it is a long loft with three access points)
The ceiling heights are around 2,5 meters.
The loft is about 1.8 meters high but sloped to either side
From these measurements (and please remember I used exact ones) triangulation is possible,
for instance:
The distance from the front of the loft, the point directly below and the far of the garden
There are of course many more calculation that can be made, I made many calculations and tests before coming
to the conclusion that the noises were coming from below. I even attempted triangulation using parabolic shields
on the recorders.
There are a few things that I noticed that I consider odd and I thought I would share them with everyone and see if
they have any ideas:
The first is the orientation of two of the steel lintels that have been used to strengthen the house.
We found three of these that span the width of the house,
The top one has been installed incorrectly, and lies on its side.
The second one is fine but unusually there is a third lintel in the basement
It sits on the floor of the basement nearest the back wall of the nail bar and has been encased in concrete,
lintels are normally seen above windows and doors, or to strengthen for loads.
But this one sits at floor level in the basement.
Secondly the rear garden, it is odd because even though it is land locked and as such has no obvious value
other that as a rear garden, it was previously sold and did not form part of my former property when I bought it.
Apologies if this post is a bit long.
If this does interest anyone let me know and I will dig out the old plans for the house
Best regards
Alan