This recording-technique is based on physiology and therefore it is possible to offer very realistic sound wave-fronts via a normal stereo loudspeaker-equipment.

These modified sound wave-fronts bring the eardrums of the listener in vibration in practical the same way as if the same listener is present on the recording-location.

This means also, that the acoustic qualities of the recording-place are registered, i.e. also three-dimensional transmitted.

This is an absolute distinct approach, other than normally executed from a technical point of view.

In the technical way people are thinking from a pure physical background.

That's why the stereo-recording-technique is restricted to one co-ordinate, i.e. between left and right.
The whole music is projected on this one co-ordinate and is offered by two speakers (or headphones) as a pseudo-spatial sound-image.

Quadrophony was, among others, deduced from this foregoing concept.
And this last concept is strongly tied to conditions of the place of the listener and of compatibility.

Of course it is possible to get a reasonable sound with tricks like phase- and intensity-differences and echo-effects.

What we however are missing are the original physical relations in an applied physiological approach.

In the holographic sound-technique, the appearing differences in the sound-frequency-spectrum have consequences for directions and for the coloring of the recorded sound.
The last is because of the ground- and matching overtones.

Especially excellent musicians are positively impressed with the present results.
They are surprised by the true position and the true natural coloring of the sound-images of the instruments and voices in the holographic registrations.

A distinguishing mark as a piece of evidence for the holographic sound is the following:
"With the correction of the balance something curious happens. In the layers of the sound-image an opposite movement takes place during the correction."(!).

Several questions were brought forward concerning this system, like:

        "Is it possible to remake an existing repertoire into a holographic one?"

Already recorded repertoire, if recorded on multi-track tapes, can be realized in a holographic way.
It is possibly to do so, in an electronic process, or via an amount of monitors, or via a combination of these two.
This electronic process can be found in our technique as described in the  U.S. patent no 4,393,270. ('controlling perceived sound source direction')

In this way it is possible to give a musical instrument any three-dimensional place you like.

You might consider putting a number of monitors in a concert-hall. Non-manipulated tracks of classical music, can be reproduced, and via these sound-monitors, then recorded in a holographic way.

First of all it is necessary to investigate these conditions in a special studio.

        "Is the effect of holographic sound-image audible in an average room with average equipment? Or do we need a special room with special equipment?"

The effect of holographic sound in an average room is of a very good quality. You can hear the quiet, very wide and deep image, even outside the room, as very natural and spatial.

During demonstrations in several dwellings, it was clear to the inmates how very different and how pleasant the music was via their own equipment.
It wasn't tiring at all, nor forcing and it was very transparent.

Holographic sound is seen, from the physiological side, so beautifully balanced, and extremely transparent, that much less energy is needed.
In this way the listener is not tempted to open up the volume, in trying to find, what is not there.

        "Is the position of the loudspeakers of any influence at the reproduction of holographic sound?"

In general, it doesn't matter so much, what the position and the distance between the two loudspeakers is.
It is possible to put the speakers at some distance, or very close. Every time it is remarkable, how stable the spatial image is and how it can be heard everywhere.

Equipment, which physically is neutral in the listening-room, will reproduce the frequency-spectrum as balanced as possible.
With such neutral equipment the holographic sound is giving its special physiological aspects in an almost perfect way.

        "Is it possible to make improvements in the reproduction-units?"

We might think of an amplification-module, which is adjusting itself for a neutral reproduction, every time before the sound is produced.
(This is also appropriate to non-holographic recordings of course)

This means equipment, having the qualities to adjust itself to a room with curtains, furniture and carpets and many people, or to an empty room with its resonance-peaks.
These aberrations can be corrected then automatically with this module.

For the Hardware this is a very important Unique Selling Point (USP)     (See below)

Too much noise is in fact a very important environment- and health-aspect.
In our opinion people will cause much less disturbance for their neighbors, when the reproducing-equipment is getting the above mentioned qualities.

        "Is it possible to use the holographic sound-technique for pop-music?"

Pop-recordings can be provided with direction-parameters, which can be used in the 'controlling perceived sound source direction'-technique, as described in the US Patent 4,393,270.

Normally these data are very hard to get (or even impossible), but with this invention we can.
With the new JOS - Recording System it is now possible to register these data with an extremely high accuracy and adjust them.

And we do have now the possibility to use these data in a computer-simulation-technique, like 'virtual reality'.

         "Is it possible to extend studio-equipment?"

Now it is possible to start with three co-ordinates instead of one.
The enormous potential of this development in sound-technique can lead to an extension of the existing studio-equipment.

                   The 7  USP-s of Holographic Sound in Soft- and Hardware

                    From the previous elucidation 7 important unique selling points are eminent.

  1. Holographic Sound can be broadcasted and received via normal equipment.
  2. Holographic Sound is very compatible, both for speakers and headphones, in Stereo and Mono
  3. Existing repertoire can often be made holographic
  4. There is a market for the manufacturing of Automatic Adjusting reproducing-equipment, in order to receive Holographic Sound(and normal) even better
  5. There is an option for extension from 1 to 3 co-ordinates for professional studios
  6. There is a huge market for the 'virtual reality"
  7. The possibility to sell holographic registering equipment for professionals and amateurs

June 1995

J.C.M. van den Berg