Tomatis Effect Research: Speech & Language

In experiments with singers, Tomatis found that when they monitored their voices with the left ear, they lost much of the control and tonality of their voices. When they monitored themselves with the right ear only, their singing ability was superior to when both ears were used. Thus, Tomatis suggested that the right ear must be the dominant ear for a person to listen effectively, since it relays sounds directly to the left hemisphere of the brain, which contains the primary processing centre for language.

If the left ear is dominant, two problems arise:

  1. The sounds from the left ear go first to the right hemisphere, and must then cross the corpus collosum connecting the two brain hemispheres to get to the language centre in the left hemisphere. This delays sound reaching the brain by a fraction of a second, causing auditory confusion and possible stuttering or dyslexia.
  2. Someone who is left ear dominant relates to sound principally through low frequencies with wavelengths between 35m and 140m, which results in them feeling distanced from the source of the sound, and consequently imparts a feeling of isolation from people s/he tries to communicate with. High frequencies give meaning in language, because they define consonants plus they carry the emotional content of the message.

By increasing the input of sound to the right ear, Tomatis was able to educate all of his subjects to become right ear dominant.

When he later worked with dyslexics and stutterers, Tomatis found that correcting their laterality would usually solve the problem.


Tomatis, A.A. (1954). Recherches sur la pathogénie du Bégaiement. Journal Francais d’Oto-Rhino-Laryngologie, m(4), 384. [Translation: Research on the pathogenesis of stuttering]

Tomatis, A.A. (1963). L’Oreille et le Langage. Paris: Le Rayon de la Science, Edition du Sevil.

Tomatis, A.A. (1969). Dyslexia.  Ontario: University of Ottawa Press, 83.

Tomatis, A.A. (1978). Education and dyslexia. Fribourg: AIAPP.

Tomatis, A.A. (1996) The Ear and Language. Dorval. Ontario: Moulin.

Average spectra of speech

Three theatre students underwent a program of Tomatis therapy for 7 months to test its effect on the long term average spectra of speech. All subjects showed a shift of vocal energy to the higher frequencies. Subjects also reported greater articulatory ease and improvement in accent variation after the treatment.


Weiss, W. (1985). Long-term average spectra of continuous speech before and after Tomatis audio-vocal training. The Journal of the Acoustical Society of America 78 (S1) p. S56
Abstract available online

Language Disorders


Estelle Bell studied the effect of treatment via Sound Therapy over a three week period on a six year old boy named Timothy who had significant language disorders: his whose speech abilities were 2½ years behind where they should be, and whose gross motor competence lagged by 18 months.

Timothy's academic performance had been poor; he rarely attempted and never completed classroom tasks, and instead roamed around the room constantly, making loud, inappropriate noises and growling and whistling. He had an unusual gait and posture, and spoke out of the left side of his mouth.

Over the course of treatment using Sound Therapy, his teachers, the researcher, and the boy's mother observed improvements in his behaviour, language and conceptual skills, articulation, concentration and social relationships. Other improvements included:


Wilson et al (1982) tested the effect of the Tomatis method when used for language disordered pre-school children over a period of two years.

The first group was given a program of remedial intervention called the Wilson program, which had previously been shown to be effective.

The second group received the Tomatis treatment in addition to the Wilson program.

It should be noted that there was no group which received Tomatis treatment alone, nor was there a non-treatment control group.

Results of the study indicated that the group receiving the Tomatis treatment made several gains in advance of the central group. In particular, testing for auditory closure and sound mimicry showed greater improvement in the Tomatis group. The assessment of parents and teachers was that the Tomatis group demonstrated greater ability to express their thoughts and feelings in words.


Bell, E. (1991) An ethnographic report and evaluation of the implementation of Audio-Psycho-Phonology (Sound Therapy) in the support of Timothy, a year two child, over a period of three weeks. Griffith University Thesis unpub.

Wilson, B.C., Iavociello, J.M., Metlay, W., Risucci, D.A., Rosati, R. & Palmaccio, T. (1982). Tomatis project final report. Paper presented at the Opening Communication Conference, Toronto, Ontario.


Van Wyk

Van Wyk (1974) tested the hypothesis that stutterers are more likely than non-stutterers to fail to develop right ear dominance in a study with 20 stutterers and 20 non-stutterers.

Using the audiolatermetric investigation method of Tomatis, Van Wyk found stutterers showed a significantly greater left ear dominance or non-specific ear preference, while fluent speakers showed a significantly greater right ear dominance.

Van Jaarsveld

Van Jaarsveld conducted two studies on stutterers and the effect of audio-psycho-phonology.

In the first study (Van Jaarsveld, 1973), 43 stutterers aged between 14 and 53 years old received auditive training by way of the Electonic Ear. A close family member and a close friend of each subject was asked to complete questionnaires before and after the training, to gauge their perceptions of the subjects' speech.

After the initial treatment, all subjects exhibited more fluent speech, with 82.5% of the participants showing significant improvement.

The subjects were followed up a year later, and it was found that 54% had maintained their improvement in speech.

In the second study (Van Jaarsveld, 1974), 30 young adult stutterers received auditory training. After the treatment, it was found that the severity of stuttering (as measured by the Lanyon SS Scale) exhibited by the subjects was significantly lower, and their speech was faster and more fluent.

The audiometric results observed supported Tomatis' previous findings that stutterers have a relative hearing loss in the hearing range of the speech area affected, especially in the right ear, and that acuity improves after re-training the ear.


Van Jaarsveld, P.E. (1973). Die terapeutiese effek van die Elektroniese oar van Tomatis op ‘n groep hakkelaars: ‘n Opvolgondersoek. Suid-Afrikaanse Sielkundige, 3(1), 1-9.

Van Jaarsveld, P.E. (1974). I-Iakkel en ‘n waardering van die tegniek van Tomatis by die remediëring daarvan. Ongepubliseerde doktorale proefskrif, Potchefstroom Universiteit vir CHO: Potchefstroom.

Van Jaarsveld, P.E. & du Plessis, W.F. (1988). Audio-psycho-phonology at Potchefstroom: a review. South African Journal of Psychology, 18, 136-143.

Van Wyk, E.M. (1974) 'n Ondersoek na ouditiewe dominansie by 'n groep hakkelaars. Ongepubliseerde M.-graad-skripsie, Potchefstroom Universiteit vir CHO: Potchefstroom.