The real sounds come to our ears in 3D. For example, the singing bird in its tree, or the fall of a token behind you, all these sounds that you can precisely locate without having to look at them illustrate your ability to hear in 3D.

Human hearing perception is very precise for localizing both in direction and in distance.The difference of time of arrival of the sound and of level of pressure between the two ears is decoded by the brain to retrieve the spatial information. However, the localization includes others factors such as the deformation applied to the sound field due to diffraction on our ear pavilions. This deformation depends of the direction of the sound wave. This factor is important for elevation localization (upper and bottom sounds).

Imagine a system that can reproduce, at home in your canapé, all the feelings as if you were at the seat 44 of the concert hall. By closing the eyes, you really think you are in the concert! You are at your home and you are listening to a 3D record of a classical music concert of philharmonic of Vienna. Through manipulating a joystick or simply by movements of your head, you can travel virtually inside the composition of the musicians: you can travel among violins, return to wind instruments and finish near the piano!

Other fields exist where the implementation of 3D sound has become a key element for a competitive differentiation. In the military field, industrials search for all means which always more protect the pilot or the infantryman while guarantying an irreproachable efficiency.

The first end user application appears in the video games. Gamers measure themselves to other gamers on line and their search for performing and realism push them to look for the best visual and audio sensations. Thus imagine to be immersed in a game at this point to be able to detect the presence of an enemy even apart from the field of vision of the screen...

These examples underline the gaps of the current systems of restitution 2d.

	In any media, the sound is the vector of emotions

Another recent phenomenon appears the convergence of the media. This phenomenon reflects the will of the individuals to feel more and more emotion at home with any multi-media equipment. It is thanks to optimized algorithms such as ours that it will be possible to profit in its settee from all the forms of media with a simple television for example...

In 1877 was invented the first monophonic reproduction system.

Then in 1958, people realized they had two ears and created stereo. Indeed, via tuning the balance of the level between right and left channel, a virtual sound can feel on a segment between the two speakers. It is a 1D technology.

For the cinema industry, Home Theater and 5.1 were created to create ambiance sounds such as rain or crowd behind the listeners. However, the technology is an extension of the stereo: placing sounds between two consecutive speakers.

Binaural or HRTF technologies were the first 3D simulated technologies. Binaural technology can reproduce and spatialize sound virtually anywhere.
However, the results depend on “binaural cues”, which means that the technology is dependant of the shape of ears and pavilions of the mannequin or of the person used to make the previous recordings. The problem is that pavilions are like fingerprints: they are different from one person to another! For one given shape of pavilion measured in laboratory, HRTF technologies work only for 20% of the population.

	A-Volute mastered all these technologies and others -such as Ambisonics or Wave Field Synthesis- to create innovative solutions for you.

From this state of the art, we decided, in 1998, to develop a new system which would reproduce the sound (undulatory aspect) such as it really arrives on our ears. We have developed prototypes for the « Nahimic » technology which enable:
> “Nahimic sound recording” of the sound space in any situation,
> a faithful restitution of this “Nahimic sound” on dedicated Nahimic headphones,
> a synthesis of the “Nahimic sound” from any mono sound.