Volume 59, Issue 2-3

Comparison was made between performance-based and competence-based approaches to the understanding of first word production. The performance-related frame/content approach is representative of the biological/functional perspective of phonetics in seeking explanations based on motor, perceptual and cognitive aspects of speech actions. From this perspective, intrasyllabic consonant-vowel (CV) co-occurrence patterns and intersyllabic sequence patterns are viewed as reflective of biomechanical constraints emerging from mandibular oscillation cycles. A labial-coronal sequence effect involved, in addition, the problem of interfacing the lexicon with the motor system, as well as the additional problem of initiation of movement complexes. Competence-based approaches to acquisition are within the generative phonological tradition; involving an initial assumption of innate, speech-specific mental structures. While various current phonological approaches to acquisition involve consideration of sequence effects and intrasyllabic patterns, they do not adequately establish the proposed mental entities in infants of this age, and are nonexplanatory in the sense of not considering the causes of the structures and constraints that they posit.

This paper uses principal components (PC) analysis to represent coronal tongue contours for the 11 vowels of English in two consonant contexts (/s/, /l/), based upon five replicated measurements in three sessions for each of 6 subjects. Curves from multiple sessions and speakers were overlaid before analysis onto a common (x, y) coordinate system by extensive preprocessing of the curves including: extension (padding) or truncation within session, translation, and truncation to a common x range. Four PCs plus a mean level allow accurate representation of coronal tongue curves, but PC shapes depend strongly on the degree of padding or truncation. The PCs successfully reduced the dimensionality of the curves and reflected vowel height, consonant context, and physiological features.

This study examined formant, jaw and tongue dorsum measurements from X-ray microbeam recordings of American English speakers producing emphasized vs. unemphasized words containing high-front, mid-front and low vowels. For emphasized vowels, the jaw position, regardless of vowel height, was lower, while the tongue dorsum had a more extreme articulation in the direction of the phonological specification of the vowel. For emphasized low vowels, the tongue dorsum position was lower with the acoustic consequence of F1 and F2 bunched closer together. For emphasized high and mid-front vowels, the tongue was more forward with the acoustic consequence of F1 and F2 spread more apart. These findings are interpreted within acoustic models of speech production. They also provide empirical data which have application to the C/D model hypothesis that both increased lowering of jaw and enhanced tongue gesture are consequences of a magnitude increase in the syllable pulse due to emphasis.

The phonetic manifestation of distinctive plosive types and click accompaniments in Xhosa was investigated with measurements of voice onset time (VOT), closure duration, voicing during closure, and burst amplitude. There is a high degree of interspeaker as well as token-to-token variability in the voiceless unaspirated plosives and clicks concerning their pronunciation with or without audible ejection. The plosives are much more frequently ejective than the corresponding clicks. If present, ejection is manifested by increased VOT, burst amplitude, or both. Duration of voicing during closure is substantial only in the implosive, but not in the ‘voiced’ plosives and clicks. After nasals the percentage of voicing during closure is high in ‘voiced’ plosives due to the very short closure duration found in that context; in the post-nasal ‘voiced’ clicks closure is mostly reduced to zero. Aspirated plosives and clicks in Xhosa show VOT values that are on average relatively long when compared to other languages. Closure duration tends to be shorter in aspirated plosives and clicks than in other categories.

In this article, two hypotheses were tested to explain attitudinal ratings like SURPRISE, SUGGESTION, REMINDER etc. of four rising nuclear contours observed in a Dutch question corpus and described as (a) H*L H%, (b) H* H%, (c) L*H H% and (d) L* H%. According to one hypothesis, the middle tones in (a) and (c) should be parcelled out, such that their absence produces contours (b) and (d), respectively, predicting communality of meaning within (a, c) that excludes (b, d). That is, (b, d) could be viewed as undershot variants of (a, c), with undershoot expressing a shade of meaning different from that of the fully realised pitch accents. This hypothesis was not confirmed by the data, though. The other hypothesis was based on the concept of the ‘frequency code’, which associ ates high/rising F₀ values with non-assertive behaviour and appeared to provide a much better model to predict listeners’ ratings.