The Tomatis Effect

Booklet presenting the Tomatis Effect, signed by Professor Louis Longchambon, professor emeritus at the University. This short text (four pages, library reference 610.221-1) constitutes one of the first public formulations of Alfred Tomatis’s three founding laws: the voice contains only what the ear hears; restoring to the traumatised ear the correct perception of frequencies instantly re-establishes phonation; any artificial modification imposed upon hearing is transmitted to the phonatory apparatus.

It was in the practice of occupational medicine that Dr Tomatis was led to the discoveries which now bear his name and which concern the relations between phonation and audition, as well as the possibility of correcting both these essential functions.

In examining workers afflicted with occupational deafness as a consequence of prolonged exposure to noisy machinery, Dr Tomatis observed that traumas of the ear were always accompanied by a certain deformation of the voice. He thereupon raised the question of whether the deformed audition was not the cause of the deformation of the voice.

Analysing more finely the defects of hearing — which manifest themselves as a diminished sensitivity to certain frequencies — he found that the frequencies poorly heard by the ear were precisely those that were deficient in the subject’s voice. This was the first fundamental discovery, the first Tomatis law, which he formulated as follows: the voice contains only what the ear hears.

Tomatis then demonstrated that if one restores to the traumatised ear the possibility of correctly hearing the frequencies poorly perceived, these frequencies are re-established in the phonatory emission, instantaneously and without the subject’s awareness. This is the second Tomatis law.

The third consists in the generalisation of this audio-phonatory relation as applied to normal ears. It may be expressed thus: the ear imposes upon the phonatory apparatus the modifications of audition that are imposed upon it artificially.

To this end, Tomatis has a subject of normal hearing speak into a microphone connected to two earphones placed on the subject’s ears. The subject then hears their own voice unaltered, and the independent observer notes no modification of the vocal emission.

Tomatis inserts, between the microphone and the earphones, an amplifier equipped with a system of filters by means of which he can modify the acoustic spectrum of the voice transmitted to the subject. The acoustic spectrum of the emitted voice immediately changes in the same manner as has just been changed in the heard voice — and this without the subject’s awareness, while the independent observer perceives it.

If, for example, the subject is an Englishman submitted to the audiometer, and one selectively reduces the intensity of the high harmonics, one hears an increased nasality in the sound emitted by the subject — and one perceives, instantly, the American accent. This example is moreover a clear sign that the auditory cause is implicated.

Dr Tomatis then set himself to investigate under what conditions the ear might preserve the benefit of the experience and progressively improve its functioning by means of artificial stimulation; and it is to this question that the Tomatis doctrine responds in affirming that forced audition, alternately maintained and suspended, succeeds in modifying both audition and phonation in a permanent manner. It is readily guessed that this last observation orients therapy towards re-education of hearing for the victims of occupational deafness, and towards a technique for correcting both the spoken and the sung voice.

But the attempt to interpret this ensemble of phenomena — the subject being a more complex case, the vowel E for example — shows that the apparatus causes the modified vowel E’ to be heard, which is transmitted in the form of a nerve impulse to the cerebral auditory area. This information is at once transformed into a phonatory command which substitutes the vocal order E’ for the vocal order E spontaneously emitted by the subject.

Under the effect of the order received, the nerves which command the muscles of the phonatory apparatus — that is, of the larynx, of the oral cavity, of the tongue and lips — adjust this apparatus so that the emission E takes place, and this beyond the consciousness and the will of the subject.

But things go much further. It is known that there exists a privileged ear, generally the right ear, whose information is exactly followed by the emitting process. Now, Dr Tomatis’s device allows the right ear, in a few sessions, to recover its predominance as the directing ear. This result is readily verified by the study of audiograms characteristic of each ear.

And the benefit of a good directing ear, as of good hearing in general, is very considerable; it has been observed, for example, that many delayed children owe the diagnosis of objects which they handle poorly in their studies either to poor hearing or to an insufficiently specialised directing ear. This is why one notes in these children a rapid automatic modification of a type that improves their auditory insufficiency, to the point that they appear transformed both intellectually and psychologically.

As for the history of stammering, it illustrates the importance of the Tomatis Effect. It is known that when one speaks before the echo of one’s own voice, the echo seems to be without effect as long as the delay between the emission of the voice and the return of the echo is too great to create confusion. But when the delay diminishes and becomes of the order of a few tenths of a second, then there appears in every normal person an irrepressible stammer. The phenomenon is obtained practically instantaneously. When the emitting head is placed a few tens of centimetres from the recording tape, the speaker hears himself with a few tens of a second’s delay on the recording, and he stammers.

Dr Tomatis then asked whether this mechanism might be implicated in stammerers, and whether a certain delay might be found in their audition-phonation system. To this end he examined a hundred stammerers. Ninety were right-handed, ten were left-handed. The ninety right-handers had the left ear as directing ear. The ten left-handers had the right ear as directing ear — both groups in contradiction with the normal state of affairs.

Dr Tomatis then reasoned as follows: in the normal audition-phonation system, the right ear of the right-hander, the directing ear, transmits the information to the left brain, which in turn transmits the order to the phonatory system. This begins at a time t. But if the right-hander has the left ear as directing ear, this latter transmits the information to the right brain. Now, in the right-handed subject, it is the left brain that effectively commands the phonatory organ, and the preceding time t is increased by the time T necessary for the information to pass from the right brain to the left brain. It is this duplication of the right-brain / left-brain circuit which produces the delay responsible for stammering: with a left directing ear, one stammers. Indeed, when Dr Tomatis, in a few sessions, definitively suppresses stammering in the stammerer, he restores the right ear to its role of directing ear.

In the face of acquisitions so significant, so strongly coordinated, it is permitted to hope that further research will allow — by the regulated enlargement of the auditory phenomenon in certain handicapped subjects, often without their knowledge — improved or even unprecedented opening of certain cerebral zones until then poorly exploited or unexploited. One senses thereby the richness of the Tomatis Effect: certainly and above all with regard to the audition-phonation process, but perhaps also with regard to certain processes of intellection.

Louis LONGCHAMBON,
Professor emeritus at the University.

Source: separately printed booklet, library reference 610.221-1 (Reliure A. Vallée Imp., Paris), 4 pages, ca. 1952. Digitised document from Alfred Tomatis’s personal archives.