Georg von Bekesy
Békésy, Georg von
BéKéSY, GEORG VON
(b. Budapest, Hungary, 3 June 1899; d, Honolulu. Hawaii, 13 June 1972)
Georg von Békésy was horn to Alexander and Paula Mazaly von Békésy. From an early age he had an avid interest in science and the line arts. Since his father was for a time a Hungarian diplomat, the family moved frequently and Békésy received his early education in Budapest, Munich, Constantinople, and Zurich. He studied chemistry at the University of Bern from 1916 to 1920 and received his doctorate in 1923 from the University of Budapest for the development ofa fast method of determining molecular weight through the diffusion coefficients of fluids. Afterward he worked primarily for the Hungarian Post, Telephone, and Telegraph Laboratory (1923–1946), in the meantime becoming a Privatdozent at the University of Budapest in 1932 and professor of experimental physics in 1940, Békésy chose to work for the telephone company because it had the best-equipped laboratory in the area. His research interests shifted from physics to biophysics after he was asked to design a better telephone earphone. In 1946 he went to Sweden, where he spent a year at the Karolinska Institute (Stockholm) working with Yngve Zotterman. He did not return to Hungary, because he felt political conditions would make it difficult for him to continue his research.
Mainly due to the efforts of Stanley Smith Stevens, Békésy went to the United States to work at Harvard University. In 1949 he accepted an appointment in the psychology department as senior research fellow in psychophysics. During his nineteen years at Harvard, Békésy received many honors and awards from a wide variety of governments, universities, and professional societies, including the 1961 Nobel Prize in physiology or medicine. In 1967, having reached Harvards’ mandatory retirement age, he went to the University of Hawaii as professor of sensory sciences, to head a laboratory built specifically for him with the assistance of the Hawaiian Telephone Company.
During his final years in Hawaii, as during his earlier career. Békésy was a solitary researcher totally engrossed in his scientific work and in his main avocation, art. He never married. In an era of collaborative group research, he rarely worked with colleagues on experimental projects. Indeed, his personal isolation may have contributed to the originality of his major achievements.
Békésy’s most important scientific contributions, for which he received the Nobel Prize, were his observations clarifying “the physical mechanisms of stimulation in the cochlea of the inner ear,” published in 1928. These observations arose from an interest of the Hungarian telephone system in the design of a better earphone. Békésy sought to determine the mechanical impedance of the ear so that an earphone could be correctly matched to it.
From his observations of the cochlea, Békésy realized that the human capacity for sharp pitch discrimination might not be adequately reflected in the vibration patterns he observed. His search for a neural explanation led to an interest in sensory inhibition and the neural sharpening processes attributed to inhibition by Ernst Mach in 1866. Mach’s research and discoveries concerning the physiological effect of spatially distributed light stimuli on visual perception—an effect without physical basis—had a great influence on Békésy in his work with sensory inhibition. Though research into the transduction properties of the inner ear has shown that sharpening due to inhibitory processes may not be as important as Békésy thought, his work on inhibition was especially important, It was Békésy who first suggested to Floyd Ratliff that the inhibitory interaction discovered by Haldan Keffer Hartline (Nobel Prize recipient in physiology or medicine, 1967) in the eye of the horseshoe crab, Limulus. was similar to the phenomena earlier described by Mach.
Initially Békésy studied sensory inhibition with auditory, visual, and tactile stimuli. But he soon realized that similar inhibitory phenomena were present in virtually all sensory modalities. He then broadened his research interests to study other similarities among other senses, especially taste, thermal sensation, temporal discrimination, and color vision.
An appreciation of Békésy’s fundamental discovery is provided by a brief review of the study of the vibration patterns on the basilar membrane in the inner ear. In the 1920’s, when his attention was directed toward a study of the mechanical properties of the ear, it was generally accepted that the cochlea was the organ where sound vibrations were transduced into nerve impulses. Because the cochlea is completely encased in temporal bone, dissection of a normally hydrated, intact specimen had not been possible. Accordingly, there was controversy concerning the nature of the transduction. Hermann von Helmholtz, for example, had suggested in 1863 that structures in the cochlea were arranged like the tuned wires of a harp and that each element resonated at different frequencies, analyzing a tone into its harmonic components. Albert von Kolliker and Karl E. Hasse later correctly directed attention to the basilar membrane, a structure suited for this analysis because it varies in width along the length of the cochlea.
Békésy was probably the first to realize that the modes of vibrations ascribed to the basilar membrane are all members of a family of vibrations that can be produced by continuously varying the thickness and lateral stress on the membrane. Indeed, simply poking the membrane to observe the shape of the resulting depression was sufficient to determine the mode of vibration.
Using superb and original microdissection techniques, Békésy was able to grind away the bone encasing the cochlea and make this key observation. He overcame the problem of dehydration by conducting the operation under a stream of water, and overcame the problem of the membrane’s transparency by sprinkling fine silver crystals on it. The depression he saw corresponded to that for traveling waves, a mode of vibration different from Helmholtz’s original suggestion, He was able to verify their presence by observing different sections of the vibrating membrane under stroboseopic light. The peak of the envelope of these vibrations was seen to move from the apex toward the base of the cochlea as the frequency of the driving tone in creased, thus providing one physical basis for the transduction of pitch, especially for tones above 200 herz.
At Harvard, Békésy was able to build a variety of large mechanical models illustrating this pattern of vibration. The most famous of these is a slotted brass tube filled with water and covered with a membrane varying in thickness. When the water in the tube is vibrated at different frequencies, the movement of the point of maximum vibration can readily be felt along the slot. This ear model exemplifies Békésy’s basic experimental approach by direct observation of phenomena made visible by intricate laboratory techniques or calibrated mechanical models.
Though the mechanical nature of his major scientific contribution and his training in experimental physics would seem to qualify him as a biophysieist. Békésy is probably more accurately described as a psychologist. In some respects this description may seem inappropriate. He taught no formal courses in the field. He had no graduate students. And his training in physical science led him to disdain the field’s rhetorical aspects.
Yet in more important respects he was very much a psychologist. Most of his work was motivated bypsychological problems, such as the best design for a telephone earphone or an audiometer; the basic similarities among all the senses; and the hearing of complex sounds. Underlying all these matters was the general psychophysical question with roots in psychology going back to Gustav T. Fechner and in physical science to Isaac Newton: How do our subjective sensory experiences of touch, sound, pain, beauty, and so on arise from the interaction of physical objects and their associated energy patterns with the sensitive receptors of our body?
Békésy sought the answer to this question in art as well as in science; for him the two were never far apart. It was the beauty of the inner ear seen through a dissection microscope that inspired him to pursue an understanding of its transduction mechanism, just as it was the beauty of a work of art that persuaded him to add it to his collection.
I. Original Works. Békésy’s most important observations on the vibration patterns of the basilar membrane were first reported in “Zur Theorie des Hoöens, die Schwingungsform der Basilarincmbran,” in Physikalische Zeitschrift, 29 (1928), 793–810. Summaries of his work and collections of his most important papers are in Experiments in Hearing, E. G. Wever. ed. and trans, (New York. 1960): and Sensory Inhibition (Princeton 1967). An autobiographical woik is “Some Biophysical Experiments from Fifty Years Ago,” in Annual Review of Physiology, 36 (1974). 1–16. See also Nobel Lectures, Physiology or Medicine 1942–1962 (Amsterdam, 1964), 719–748.
Békésy’s experimental apparatus is in a small museum at the Békésy Laboratory of Neurobiology. University of Hawaii. Most of his papers and other materials are at the Library of Congress. His ait collection is at the Nobel Foundation in Stockholm.
II. Secondary Literature. C. G. Bernhard, “Georg von Békésy and the Karolinska Institute,” in Hearing Research, 22 (1986). 13–17; Floyd Ratliff, “Georg von Békésy,” in Biographical Memoirs. National Academy of Sciences, 48 (1976), 25–49. with complete list of Békésy’s writings; Jürgen Torndorf. “Georg von Békésy and His Work,’ in Hearing Research. 22 (1986). 3–10: and Jan Wirgin. eds., The Georg von Békésy Collection (Malmö, Sweden, 1974), a catalog of his art collection that includes a biographical sketch.
Stephen R. Ellis