Volume 134, Issue 1, July 2013
Index of content:
- SPEECH PRODUCTION 
134(2013); http://dx.doi.org/10.1121/1.4807639View Description Hide Description
This paper presents an automatic procedure to analyze articulatory setting in speech production using real-time magnetic resonance imaging of the moving human vocal tract. The procedure extracts frames corresponding to inter-speech pauses, speech-ready intervals and absolute rest intervals from magnetic resonance imaging sequences of read and spontaneous speech elicited from five healthy speakers of American English and uses automatically extracted image features to quantify vocal tract posture during these intervals. Statistical analyses show significant differences between vocal tract postures adopted during inter-speech pauses and those at absolute rest before speech; the latter also exhibits a greater variability in the adopted postures. In addition, the articulatory settings adopted during inter-speech pauses in read and spontaneous speech are distinct. The results suggest that adopted vocal tract postures differ on average during rest positions, ready positions and inter-speech pauses, and might, in that order, involve an increasing degree of active control by the cognitive speech planning mechanism.
134(2013); http://dx.doi.org/10.1121/1.4807566View Description Hide Description
Previous research has shown disagreement regarding the nature of stress in French. Some have maintained that French has lexical stress on the final syllable of each word; others have argued that French has no lexical stress, only phrasal stress. A possible source of evidence on this issue is vocal music. In languages with lexical stress, such as English, it is well known that stressed syllables tend to occur at “strong” positions in the musical meter (some evidence will be presented supporting this view). A corpus analysis was performed to investigate the degree of stress-meter alignment in French songs. The analysis showed that (excluding syllables at the ends of lines) the final syllables of polysyllabic words tend to occur at stronger metrical positions than non-final syllables of those words; it also showed that monosyllabic content words tend to occur at stronger positions than monosyllabic function words. While conflicts between stress and meter are much more common in French than in English vocal music, these results suggest that French poets and composers recognized distinctions of stress between syllables of polysyllabic words and between monosyllabic content and function words.
Measuring body layer vibration of vocal folds by high-frame-rate ultrasound synchronized with a modified electroglottograph134(2013); http://dx.doi.org/10.1121/1.4807652View Description Hide Description
The body-cover concept suggests that the vibration of body layer is an indispensable component of vocal fold vibration. To quantify this vibration, a synchronized system composed of a high-frame-rate ultrasound and a modified electroglottograph (EGG) was employed in this paper to simultaneously image the body layer vibration and record the vocal fold vibration phase information during natural phonations. After data acquisition, the displacements of in vivo body layer vibrations were measured from the ultrasonic radio frequency data, and the temporal reconstruction method was used to enhance the measurement accuracy. Results showed that the modified EGG, the waveform and characteristic points of which were identical to the conventional EGG, resolved the position conflict between the ultrasound transducer and EGG electrodes. The location and range of the vibrating body layer in the estimated displacement image were more clear and discernible than in the ultrasonic B-mode image. Quantitative analysis for vibration features of the body layer demonstrated that the body layer moved as a unit in the superior-inferior direction during the phonation of normal chest registers.
134(2013); http://dx.doi.org/10.1121/1.4807510View Description Hide Description
The effects of laryngeal specification on the timing of supra-laryngeal articulations have so far received little attention. Previous research has shown that German—but not French—mixed-voicing clusters are produced with less articulatory overlap than phonologically fully voiced clusters. Articulatory and acoustic data of labial and velar stops as simple onsets and in stop + /l/ clusters are examined to probe the causes for this cross-linguistic difference in the light of the different voicing implementations of French and German. The absence of overlap in German mixed-voicing clusters is attributed to the requirement of a time slot for the stop's aspiration phase. Since French does not commonly have aspirated stops, French clusters are expected to pattern with the voiced German clusters. The results confirm that voicing patterns established for simple onsets in the literature in terms of voice onset time of both German and French also obtain in clusters. Furthermore, the data show that contrary to the expectations French clusters pattern with German mixed-voicing clusters. This low degree of overlap in both voiceless and voiced French clusters indicates that overlap is restricted by aerodynamic requirements which result from the implementations of the voicing contrast.
The effect of prosodic weakening on the production and perception of trans-consonantal vowel coarticulation in German134(2013); http://dx.doi.org/10.1121/1.4808328View Description Hide Description
The present study considers whether coarticulation in production and its relationship to categorization could provide a synchronic basis for the prevalence of sound change in unstressed syllables. The size of V2-on-V1 coarticulation in the production of /pV1pV2l/ non-words (V1 = / / and V2 = /e, o/) produced by German speakers and with stress falling either on the first or second syllable was compared with forced-choice perceptual categorization of resynthesized versions of these non-words. In speech production, /ʏ/ but not / / was perturbed by anticipatory V2-on-V1 coarticulation. Stress had no influence on coarticulation but caused target undershoot in / /. The same speakers compensated for coarticulation in perception: however, in the unstressed context the speakers compensated less and their diminished compensatory coarticulation was shown to be linked to / /-undershoot. Taken together, these results point to a mismatch between coarticulation and categorization that is suggested as a possible source of sound change: whereas de-stressing did not affect V2-on-V1 coarticulation in production, it weakened V2's influence on perceptual / / categorization. The evidence that this mismatch is indirectly caused by stress-dependent reduction in / / that is unrelated to the V2-source of the coarticulation is also consistent with a model of sound change as non-teleological.