In this paper, the formant transitions in vowel q-stop consonant q-vowel utterances spoken by Swedish, American, and Russian talkers are studied spectrographica]ly. The data suggest a physiological model in terms of which the VCV articulations are represented by a basic diphthongal gesture with an independent stop-consonant gesture superimposed on its transitional portion. This interpretation necessitates a reevaluation of the locus theory proposed by the workers of the Haskins Laboratories. Some conclusions about the general nature of the neural instructions behind the VCV gestures are discussed. INTRODUCTION PEECH production involves two fundamental aspects: the stationary properties of phoneme realization and the dynamic rules governing the fusion of strings of phonemes into connected speech. Recent research has dealt successfully with the acoustic description of static speech sounds. The dynamics of articulation, however, have received much less attention, and reports of quantitative studies in this area are relatively rare. A selection of references is given below.•-•3 • R. H. Stetson, Motor Phonetics (North-Holland Publ. Co., Inc., Amsterdam, 1951). •' P. Menzerath and A. de Lacerda, Koartikulation, Steuerung und Lautabgrenzung (Fred. The present work deals with some of the apparently very lawful rules that describe how voiced stops are coarticulated with vowels in vowel-consonant-vowel (VCV) context. As a preliminary illustration of the type of effects investigated, Fig. 1 shows a pair of VCV words chosen from the material described in more detail later. In both utterances, the initial vowel is/•/ and the consonant is/g/. The final vowel is different. It is /y/in the left and/u/in the right part of the Figure.The talker is a male Swede.When the intervocalic consonant is inspected for changes that might be due to the variation imposed by the vowel context, the following observation presents itself immediately. The second-formant transition in the vowel preceding the stop is rising when the vowel following the stop is/y/, but it is falling when the vowel following the stop is/u/. There is also some variation in the third-formant transition of the initial vowel. The articulatory motion from the initial vowel into the/g/, as mirrored by the formant transitions, is apparently modified by the vowel that is to.follow the/g/.

The essential features of the coarticulation properties of Swedish dental stops in vowel-consonant-vowel contexts can be described by the formula s(x; t)=v(x; t)q-k(t)[c(x)--v(x; t)•wc(x), where x represents the longitudinal distance between lips and glottis and s(x; t) denotes the shape of the vocal tract at some instant of time, t, during the vowel-consonant-vowel utterance. The vowel component, v(x; t) is a linear combination of the three "extreme" shapes of the vowels/i/,/a/, and/u/with weights that vary as functions of time. The consonant is represented by c(x), an ideal target shape, and wc(x), a so-called coarticulation function. A time-varying factor k(t) represents the degree of excursion of the consonantal gesture. Vocal tract shapes measured from x-ray motion pictures of a set of Swedish vowel-consonant-vowel utterances compare well with shapes generated by the formula. This result is consistent with our earlier conclusions about coarticulation, viz., that the vowel and consonant gestures are largely independent at

This study examines the discrimination and identification of synthetic rounded and unrounded vowels by speakers of two languages (English and Swedish). The unrounded vowels are phonemic in both languages, whereas the rounded vowels are phonemic only in Swedish. A subsidiary aim of the study is to compare the perception of the synthetic vowels with that of synthetic consonant-vowel syllables in which the consonants are stops arranged along a continuum from /b/ to /d/ to /g/. The data indicate that the ability of subjects to discriminate between the vowels is relatively independent of their linguistic experience: Swedish and American English subjects exhibit similar performance in the discrimination tests, though they have somewhat different identification functions. The discrimination functions are characterized by peaks and valleys, suggesting that listeners can discriminate given shifts in the vowel formant frequencies more readily in some vowel regions than in others. Comparison of the data on stop-consonant and vowel perception is consistent with earlier findings: the number of discriminable tokens along the stop-consonant continuum is roughly equal to the number of absolutely identifiable items (three in this case) ; on the other hand, the number of discriminable vowels is much greater than the number that can be absolutely identified. The data are in accord with the view that a human listener uses different modes in the perception of steady-state vowels and stop consonants.

No abstract

The aim of this experiment was to examine the identification and discrimination of a series of rounded and unrounded vowels by a group of listeners (Swedish) who were familiar with both types of vowels. The following groups of stimuli were assembled using the Stockholm OVE II speech synthesizer, and were arranged in the form of identification tests and ABX discrimination tests: (1) a series of thirteen vowels in which the first three formants varied in approximately equal logarithmic steps through three unrounded vowels (roughly /i/, /ɪ/, and /ɛ/); (2) a similar series in which the second and third formants varied in approximately equal logarithmic steps from the unrounded /i/ through the rounded /y/ to the rounded /u/; and (3) a series of thirteen vowels constructed by taking /i/ as a center and then including the first six steps along the unrounded continuum and the first six steps along the rounded continuum. The discrimination functions showed small peaks near the phoneme boundaries; i.e., discrimination between adjacent stimuli on the vowel continuum was better when the stimuli were near phoneme boundaries. Discrimination was at least as good for the rounded series as for the unrounded series, and seemed to be especially sharp in the region where rounding first became apparent.