LANGUAGE AND SPEECH, 1989,32(3), 221 -248 221 THE ACOUSTIC VOWEL SPACE OF MODERN GREEK AND GERMAN* ALLARD JONGMAN, MARIOS FOURAKIS and JOAN A. SERENO Central Institute for the Deaf, St. Louis The spectral characteristics of vowels in Modem Greek and German were examined. Four speakers of Modern Greek and three speakers of German produced four reperitions of words containing each vowel of their native language. Measurements of the fundamental frequency and the first three formants were made for each vowel token. These measurements were then transformed into log frequency ratios and plotted as points in the three-dimensional auditory-perceptual space proposed by Miller (1989). Each vowel token was thus repre- sented by one point, and the points corresponding to each vowel category were enclosed in three-dimensional target zones. For the present corpus, these zones differentiate the five vowels of Modern Greek with 100% accuracy, and the fourteen vowels of German with 94% accuracy. Implications for the distribution of common vowels across languages as a function of vowel density are discussed. Key words: vowel space, Greek, German INTRODUCTION The process of defining a vowel space for a language, or a universal space for all languages, can be characterized as having three facets corresponding to three different stages in the communication process (Lindblom, 1986). The articulatory stage, at which the vocal tract is shaped so as to produce the intended vowel, defines an articulatory vowel space by the possible positions of the tongue and the jaw, and by the shape of the lips. The acoustic stage, at which the sound radiating from the lips propagates through air, defines an acoustic space by the relative distribution of energy in the time and frequency domains. Finally, the auditory stage, at which the sound is processed by the The first and third authors are presently at the Max Planck Institute for Psycho- linguistics, Nijmegen, The Netherlands. A partial report of the results was presented at the 113th Meeting of the Acoustical Society of America in Indianapolis, IN, May 11-15, 1987. The research was supported by NIH Grant ND21994and AFOSR Grant 860335 to Central Institute for the Deaf. The authors wish to thank James D. Miller, John W. Hawks, Steven J. Sadoff, Frank E. Kramer, and Melissa P. Piasecki for invaluable assistance. Address all correspondence to Allard Jongman, Max Planck Institute for Psycho- linguistics, P.O. Box 310, 6600 AH Nijmegen, The Netherlands.