Showing papers by "Kevin G. Munhall published in 1986"

Acoustic and articulatory evidence for consonant‐vowel interactions

Abstract: Previous acoustical research [e.g., C. Fowler, Phonetica 38, 35–50 (1981)] has suggested that consonants and vowels are not produced strictly sequentially but rather overlap in time. By this account, the degree of co‐production of underlying segments affects the pattern of the resulting acoustical durations. In the present experiment, two subjects produced utterances of the form CVC(C), where the vowels were either /e/ or /ae/ and the following consonants were /p/, /k/, /s/, /ps/, /ks/, /sp/, or /sk/, Movements of the lips and jaw were monitored with a Selspot system. Laryngeal movements were measured by means of transillumination, and the accompanying acoustic signal was recorded. Analysis of the acoustic durations revealed that vowel duration was shorter when followed by a cluster than by a singleton in both vowel contexts. However, the following consonant durations were longer for the vowel /e/ than for /ae/. Analyses of the lip and jaw kinematics suggested that the vowel shortening in the cluster contexts was produced in part by greater temporal overlap of the underlying segments. The influence of the intrinsic vowel duration on the following consonants may reflect a syllabic constraint on articulatory timing. The results will be discussed in terms of the articulatory structure of phonetic segments and the sequential coordination of consonant and vowel gestures. [Work supported by NINCDS.]

Laryngeal compensation following sudden oral perturbation

Abstract: Recently, there have been a number of demonstrations of rapid goal‐directed compensation in remote articulators when an articulator is perturbed unexpectedly during ongoing speech. Much of this research, however, has involved articulators that cooperate to produce a single vocal tract constriction (i.e., tongue‐jaw, lips‐jaw). In this experiment, spatially more separate articulators are examined that are simultaneously active in the production of a phonetic segment (i.e., the larynx and the lip‐jaw complex). Three subjects produced the nonsense utterance “/ipip/ again” and the lower lip was unexpectedly loaded in the first vowel or during the closure for the first /p/ on a small proportion of the trials. Laryngeal behavior was monitored using transillumination and fiberoptic videotaping. In addition, intraoral air pressure just above the folds was monitored. Oral movements were recorded with a Selspot system. Acoustically, the first /p/ closure in “ipip” was shorter in duration and the voice onset times were longer in the perturbed trials. An examination of the laryngeal gestures during the production of the first /p/ revealed longer adduction durations in the perturbed conditions than in the control trials and a longer overall abduction/adduction cycle. The results will be discussed in terms of task‐dependent articulatory coupling. [Work supported by NINCDS.]

Patterns of interarticulator phasing relations

Abstract: The difficulty in identifying phonetic segments in the acoustic signal of speech is a commonly recognized problem. One proposed solution is that the integrity of individual segments is maintained by stable timing relations between the articulators. Recently, Kelso and Tuller [e.g., J. Acoust. Soc. Am. Suppl. 1 77, S53 (1985)] reported an invariant relation between jaw and lip gestures in various VCV contexts. Specifically, the onset of upper lip lowering for the intervocalic consonant was found to have a constant relation to the vowel‐to‐vowel jaw cycle in both time and position‐velocity phase‐plane domains. In this paper, we examine the additional effects of syllable affiliation and intervening consonant identity. The data show that the upper lip's lowering onset, relative to the position‐velocity state of the jaw (phase angle), varied as a function of speaking rate and stress. In addition, the position of the syllable boundary (before or after the intervocalic consonant) and the consonant identity (p vs...