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cochlear outer hair cells whose role as active filters would final- ly be established around 1985. Cochlear microphonics remains an excellent tool for evaluating transducer currents through sensory cells in vivo to this day.
Back in France and full of ideas, Jean-Paul Legouix now faced a typically French problem—how to initiate research in a country where neither the field of cochlear acoustics nor cochlear physiologists existed. Fortunately, to work-around intractable problems, France had also conceived “system D” (D for “débrouille,” or do-it-yourself). But first things first—Jean- Paul completed his Ph.D. (with his frogs) and secured a stable CNRS position. He was offered and accepted an “administra- tive solution” by Professor Alfred Fessard who taught general neurophysiology at Collège de France and placed him on his “team” so that CNRS would not worry about Legouix operat- ing as a free agent.
The Collège de France was created by king François I around 1500 on the northern slope of Montagne Sainte Geneviève (across the street from the Sorbonne) This presti- gious school offers tenure to outstanding professors on what appeared to be a seemingly casual basis—only a few “ground- breaking” lectures each year, no tuition, no degrees, and unfor- tunately, no room for labs (not even for Professor Fessard). The problem of where to start building a lab and acquiring col- leagues was thus left for Jean-Paul to solve. At the same time, the psychophysicist René Chocholle, former student of Henri Piéron, one of the founders of scientific psychology in France, happened to be using a soundproof room in the cellar of a neighboring institute. Jean-Paul Legouix moved there in 1956 when a room became available next to Chocholle’s anechoic chamber. However, this stroke of luck was somewhat offset by the fact that the room had no window, and was next to the trash cans and waste pipes for the whole building.
In the spirit of “System D,” Jean-Paul Legouix, rebuilt the required equipment from scratch and set out exploring many important topics—either alone or with students, engineers and otolaryngologists who had become well aware that their clini- cal skills would improve greatly if their fundamental knowl- edge were expanded. In 1960, a new building was constructed by the Collège de France and Jean-Paul Legouix at last found himself surrounded by decent facilities that included a spec- tacularly large, first-quality anechoic room. Moreover, the 60s were to be a grand decade for French research overall. President de Gaulle at last considered that pouring funds into national research agencies was a first priority.
The scope of Jean-Paul Legouix’s research was broad and
inventive, mostly involving in vivo measurements of the guinea pig cochlea. In recent times, it has become ordinary to work with isolated sensory cells and the use of molecular probes are commonplace, yet the issues tackled in Legouix’s lab are still with us, often with the same focus and formulation. Here is a short list—nonlinearities in transduction currents that appear in cochlear microphonics; the roles of anoxia and polarization in scala media; masking and two-tone suppression; effects of acoustic trauma; the effects of potassium intoxication and excessive hydrostatic pressure that are still invoked in current models for Menière’s disease. Jean-Paul Legouix achieved clever studies of the effect of a mechanical impulse directly applied to the basilar membrane, using guinea pig hair as a makeshift probe, at a time when Mössbauer and laser measurements were hardly available. Finally in 1986–7 just before his retirement, he started work on otoacoustic emissions. Jean-Paul published insights into the mechanisms of bone conduction, the role of cochlear windows, and the giant middle ear cavities found in some rodents. The phase shifts in the cochlear microphonics he observed when blocking, stiffening or loading the ossicular chain helped him to contribute to explaining the outcome of the Weber test. Bone conduction is still a leading-edge topic for ear-nose-throat (ENT) surgeons because bone-anchored hear- ing aids have become increasingly useful, and for physiologists who, only a few years ago, discovered a novel condition—semi- circular canal dehiscence (i.e., splitting open) characterized functionally by the presence of paradoxical air-bone gaps. Partly because he was a medical doctor–although he conduct- ed his entire career in fundamental science, and partly because the example of CID and Hallowell Davis had been particularly inspiring, Legouix was deeply concerned that the activity of his research laboratory should be useful, not only for physicians, but also for students, engineers, deaf people, and their teachers. Nowadays, research has sometimes branched into so many independent parts that the lesson that an efficient synthesis can come out of careers such as Jean-Paul Legouix’s deserves to be recalled from time to time.
After retiring, Jean-Paul Legouix devoted his time to the enjoyment of family life, while continuing to give free rein to his passion for the do-it-yourself. But this time it was to finish fitting out his home, built some years earlier. His is survived by his wife Michèle, his children Philippe and Caroline and five grandchildren, from 17 to 27 years old. All of them share won- derful memories of the fulfillment of Jean-Paul.
A tribute by Paul Avan
44 Acoustics Today, October 2009