Colloque Didier Demolin 2023 - Jacqueline Vaissière, "Demolin, Rousselot, Ohala et la phonétique expérimentale"

Abbé Jean-Pierre Rousselot (Rousselot 1846-1924) is considered the founder of experimental phonetics. In 1896, Rousselot created the laboratory of experimental phonetics at the Collège de France and introduced the laboratory study of linguistic structures. He outlined the principles and experimental techniques of experimental laboratory in two volumes entitled « Principes de phonétique expérimentale » (Rousselot 1897-1908). Rousselot’s approach goes beyond phonetics in his insistence on the need to reproduce the observed phenomenon in laboratory conditions, under controlled conditions, to explain it. Rousselot encourages the development of experimental approaches in other parts of linguistics. The actual Labex EFL, “Empirical foundations of Linguistics” is completely in line with Rousselot’s point of view.
John Ohala and Didier Demolin are great admirers of Rousselot, most of whose writings they are familiar with. They espouse all of his ideas about the need to experiment and followed his boldness in applying all the techniques available at the time. John is generally regarded as Rousselot’s best successor. Both John and Didier regarded Rousselot as an intellectual father figure.

The three scientists share the necessity of integrating phonetics (the study of the sounds) and phonology (the study of the structures), contra phonologists proposing theories without experimental evidence and developing dynamics of phonological systems.

John and Didier share multiple collaborations or interests with other disciplines such as animal communication and evolution: Morton and Ohala’s frequency code, dressing the link between the expression of emotion in animals and human speech; Didier’s studies on the vocalizations and vocal morphology of Bonobos and chimpanzees, and showing the existence of syntax and recursion in non-human vocalizations, etc. One of Ohala’s main contributions is the illustration of the idea first expressed by Marguerite Durand that the listener is a source of change in sound, etc. Both John and Didier have disputed the claim about the contribution of subglottic pressure to Fo control (Glottal resistance, Fo, intensity, glottal opening, larynx height, and vocal fold tension). Both conduct adventurous experiments and direct measurements of subglottic pressure via tracheal puncture for this purpose. Both have studied different aspects of nasality, etc.

All three share a common interest in sound changes and in a number of languages, through the visit of researchers from different countries in Rousselot’s lab, South American, and African languages for Didier, with more fieldwork for Didier, on a particular aspect in the Mangbetu, Lendu, Mangbutu-Efe, Hendo, Hadza, Iraqw, Karitiana, Guarani, Nasa Yuwe, Namtrik, Muong and languages.

All three share a strong interest in instrumentation and methodologies from other disciplines and in the development of new instruments. All three contribute to the development of experimental methods in an innovative way. Ohala was the first to adapt the whole-body plethysmograph to the measurement of subglottic pressure in speech. He used the photoelectric thyroumbrometer for the measurement of laryngeal movements, the nasograph, etc., and EMG with an otolaryngologist to study the contribution of the intrinsic muscles and some extrinsic muscles of the larynx. Didier was the one who pioneered the use of MRI to study aspects of Bantu and French and was directly involved in the development of EVA (in Aix-en-Provence) and portable electromyography devices.

Special to Didier are 1) the special speech aerodynamics database, in line with Ferdinand Brunot’s archive, but with precious physiological data, 2) more effort to include factors such as sociolinguists in explaining the sound change in progress (Rousselot has insisted on sociolinguist factors, factors that Ohala put aside because they could not be studied in a laboratory, 3) more fieldwork, and 4) ethnomusicology.