Digital or analogue

Alfred A. Tomatis’s reply to a question raised at the Forum, Paris 1994. In two pages, the author explains why his method and his Electronic Ear operate in analogue and not in digital mode: the human nervous system — an information motorway forged by evolution — itself operates in analogue mode, and the cortical recharge sought by the treatment requires that no atom in the chain of sonic transmission be out of step with this rhythm. Tomatis cites in support Japanese experiments showing that the cortical projections differ according to whether the captured sounds are of analogue or digital origin.

Alfred A. TOMATIS
Forum, Paris 1994

Question

Why do you recommend, in the application of your method, the use of the analogue rather than the digital system?

Reply by Alfred A. Tomatis

The appearance, some years ago, of digital sound in the modern world has not failed to raise many questions among the professionals who apply my method. I fully understand this, and I owe it to them to spell out what I have already told them on several occasions. There remains, in fact, the question of the impact of such a product inserted into our field — audio-psycho-phonology — and of whether it is usable, or at least compatible, with our kind of activity.

That is precisely where the real and crucial point of our debate lies. The issue is to show what the effects are, on the nervous system, of capturing and transmitting sonic material, since it is indeed at this level that we operate from the moment we speak of sounds. One can readily see that having at one’s disposal a process never equalled on the technological plane, of such high quality, truly demands serious attention. All this leads us to set out the fundamental differences that exist between the neuro-physiological effects of the sounds emitted by one system and the other. Their activities, at the level of the brain, are different. It is therefore necessary to investigate why, from the point of view of cortical recharge, the processes diverge.

Experiments carried out in certain laboratories, notably in Japan, have shown that the projections on the cortex do not have the same configuration. Those produced by the audition of analogue sounds were more extensive on the cerebral map than those arising from the audition of digital sounds. The effects produced by these two forms of sonic emission must therefore be studied in depth. The brain receives them in very different ways. By its very structure, it is an analogue system. The human nervous system has a specificity which makes of it a means of communication, an information motorway whose system of transmission has well-defined characteristics. It functions in an analogue mode that the laws of evolution have forged since the dawn of time.

We know the mode of action of digital sound, which operates on the nervous system and notably at the level of the cochleo-vestibular apparatus. We are likewise not unaware of the harmful effects that may arise at cardiac level, nor of those which go so far as to call into question the inner mechanisms of memory. We must take to heart the idea that the brain is literally seized in its globality. It operates indeed in its totality. There will not be one of its atoms that is not called upon. It must also be specified that the natural sound of a voice or that of an orchestra is captured by one or several microphones. These are always analogue sensors. The role played by the microphone is, in fact, that of a kind of transformer that converts the natural sound perceived through the air into an electrical signal proportional to the sound perceived. This transformation is of analogue type. A loud sound perceived corresponds to a strong electrical signal. The latter is then processed electronically.

The Electronic Ear we use in Audio-Psycho-Phonology is a device for analogue processing. This device corresponds to certain data of the functioning of the human ear in its mechanisms of listening. It is adapted to the transmission of sound to the cortex and then throughout the body via certain networks I have called the “integrators”. This whole functions on an analogue rhythm, which corresponds to the neuro-physiological responses of the human organism. It must therefore be known that, within the framework of our therapeutic action, one can use only a set of devices (electronic ears, headphones, microphones, etc.) functioning in an analogue mode. This in order to ensure maximum cortical recharge.

On the therapeutic plane, account must be taken of the requirements of the human nervous system, which has not followed the same processes of progression as current technology. The brain must be taken as a vast network whose aim is to bring together the whole of the cells so that they act in unison, in accordance, of course, with their own attributions that individualise them within a functional programme.

The result is that the use of digital sound, within the framework of our therapeutic action under Electronic Ear, cannot be envisaged at the present time.

Source: Alfred A. Tomatis, “Numérique ou analogique”, Forum, Paris 1994 (two typescript pages). Document digitised from the personal archives of Christophe Besson.