Treatments of synesthesia in the arts and humanities generally assume a clear distinction between the neurological condition and the literary device. Synesthetes’ descriptions of colors seen in connection with music, for example, are thought to differ fundamentally from common expressions that rely on transpositions across sensory dimensions (“bright vowels”). This has not always been the case. The distinction emerged over the course of the twentieth century, as scientists sought to constitute “synesthesia” as a legitimate object of modern science. On the Colors of Vowels investigates the ambiguity of visual descriptions of vowels across a wide range of disciplines, casting several landmark texts in a wholly new light. The book traces the migration of sound-color correspondence from its ancient host (music) to its modern one (vowels), investigating the vocalic Klangfarben of Hermann von Helmholtz’s monumental Sensations of Tone , the vowel colors reported in early psychology surveys into audition colorée (colored hearing), the mis-matched timbres that form poetry’s condition of possibility in Stéphane Mallarmé’s “Crisis of Verse,” and the vowel-color analogy central to both the universal alphabets of the nineteenth century and the phonological universals of the twentieth. The book’s final chapter turns to an intricately detailed account of vowel-color correspondence by Ferdinand de Saussure, suggesting how the linguist’s sensitivity to vowel coloration may have guided his groundbreaking study of Indo-European vocalism. Bringing out the diverse ways in which visual conceptions of vowels have inflected the arts and sciences of modernity, On the Colors of Vowels makes it possible to see how discourses of the nineteenth and twentieth centuries crafted the enigma we now readily recognize as “synesthesia.” A thrilling journey to the edges of the mind―and into the heart and soul of language and literature. Guiding us through famous poems and forgotten treatises with equal ease, Yamaguchi unfolds a powerful new picture of how words work. ---Shane Butler, Johns Hopkins University Liesl Yamaguchi’s beautifully written and carefully argued book investigates the role played by vowel color in nineteenth and early twentieth century theories about language, from Indo-European linguistics, to French Symbolist poetics, to the science of acoustics. The idea that the notion of vowel color is crucial for the development of free verse as a modern poetic category is explosive and exciting. With clarity and precision, Yamaguchi zeroes in on one of the most stubbornly nebulous categories in the linguistic and poetic tradition. ---Sarah Pourciau, Duke University . . .[Yamaguchi's] book is compelling and important. . . the reader is left with a deeply nuanced awareness of a crucial, fascinating, and elusive aspect of language. . . ― Nineteenth-Century French Studies “A thrilling journey to the edges of the mind―and into the heart and soul of language and literature. Guiding us through famous poems and forgotten treatises with equal ease, Yamaguchi unfolds a powerful new picture of how words work.”― Shane Butler , Johns Hopkins University “Liesl Yamaguchi’s beautifully written and carefully argued book investigates the role played by vowel color in nineteenth and early twentieth century theories about language, from Indo-European linguistics, to French Symbolist poetics, to the science of acoustics. The idea that the notion of vowel color is crucial for the development of free verse as a modern poetic category is explosive and exciting. With clarity and precision, Yamaguchi zeroes in on one of the most stubbornly nebulous categories in the linguistic and poetic tradition.”― Sarah Pourciau , Duke University Treatments of synesthesia in the arts and humanities generally assume an inviolable distinction between the neurological condition and the literary device. A synesthete’s description of seeing a color in connection with a vowel, for example, is understood to be categorically distinct from common expressions that require transposition across sensory dimensions (“bright vowels”). On the Colors of Vowels challenges this assumption by tracing the historical interests that drove its emergence in the twentieth century and investigating the ambiguity of visual vocalic description in the nineteenth. The book’s five chapters expose the centrality of colored conceptions of vowels to discourses in physical acoustics, poetics, phonetics, phonology, and opera, casting major works by Hermann von Helmholtz, Stéphane Mallarmé, Roman Jakobson, Richard Wagner, and Ferdinand de Saussure in a whole new light. Bringing out the diverse ways in which visual conceptions of vowels have inflected the arts and sciences of modernity, On the Colors of Vowels makes it possible to see how discourses of the nineteenth and twentieth centuries crafted the enigma we now readily recognize as “synesthesia.” Liesl Yamaguchi is Assistant Pro