I'll risk raising my head above the parapet on this subject. As it
is something I have been playing with for some time
The problem I have is finding a way of tackling the subject without
getting long winded and without unintentionally upsetting anyone.
In the context of a layout, sound has to be approached the same way
as the experienced modelers in this forum approach the use of light.
You manipulate it to fool the viewers brain into thinking they are
looking at the real thing......from a distance. On any layout
a multitude of techniques are used to achieve the illusion, but any
given model on the layout will only use a subset of those techniques.
The science of how the human brain deals with sound is called
psychoacoustics. You may care to have a look here for a primer
Consider a simple example which most people are familiar with -
a stereo system. Two speakers correctly positioned can fool the brain
into believing that sounds are originating from points between the speakers.
Physics must also be considered.
Realistic on-board sound
from a diesel engined vehicle - forget it. The speaker is too small to
reproduce the low frequencies. Fortunately, electronics can help by
employing active motional feedback the low frequency range of the
speaker can be extended. Unfortunately, not sufficiently
However, the brain cannot locate the source of low frequencies so
these can be provided by a speaker under the layout whilst leaving
the on-board speaker to reproduce the high frequencies.
I will present one other example, Arc Welding. These are essentially
high frequency sounds, worse it is modified white noise. Given that
it is at a fixed location it could be fed through a stereo system.
That will work for one person whose
head is clamped in a fixed position. For some reason I do not think
this is practical
. OK, so place a speaker at each corner of the layout.
Better, but only to on person at a defined location. So the
sound must come from a speaker located where the activity is taking
place on the layout. Now all viewers can match the sound to the activity.
Then there is..... no forget it, I'm missing the comedy show of the week