Volume 44, Issue 3

Three experiments investigated the use of lexical stress in auditory word recognition. Speech voicing continua were created in which lexical status resulted in one end-point constituting a real word and the other end a nonword (e.g. diGRESS-tiGRESS, in which digress is a real word, and DIgress-TIgress, in which tigress is a real word). Subjects’ identification of the initial segment of these items was biased in the midrange of the continua in that they were more likely to report a segment that resulted in a real word than one that resulted in a nonword. Alternative acoustically based explanations are discounted in favor of a lexically based account of the data. Possible mechanisms underlying the effect of lexical stress on speech perception are discussed.

The literature describes two kinds of durational influence on the syllables of an utterance. They are a lengthening of syllables before many syntactic boundaries (‘domain-final lengthening’) and a shortening of stressed syllables followed by unstressed syllables (‘foot-level shortening’). In the present study we examined the relationship between these two timing phenomena. In particular, we examined the possibility that syntactic boundaries at which lengthening occurs delimit the domains over which foot-level shortening is realized. To test this hypothesis, we varied the syllabic structure of metrical feet spanning word boundaries that either coincided with a noun-phrase (NP)/verb-phrase (VP) boundary or did not. Comparison of stressed syllable durations in these conditions failed to confirm the hypothesis. Instead, unstressed syllables shortened stressed syllables by the same duration across an NP/VP boundary as within a phrase. Our findings suggest that the two effects are independent. The finding that foot-level shortening spans finally lengthened syntactic boundaries is discussed in relation to theories of the shortening effect.

The articulation of pharyngeal consonants in Arabic is still not fully understood. The production of these sounds by a small group of speakers of an Iraqi dialect was analysed by means of acoustic and aerodynamic techniques. It was found that both /ħ/ and /?/ could be said to be produced by a constriction in the pharynx (whereby the possibility of epiglottal involvement cannot be excluded), but that laryngeal tension may also play an important role. Vowels preceded or followed by pharyngeals have lowered and centralized allophones. High rates of airflow for /ħ/ may be facilitated by lowering the velum. Both sounds could be regarded as approximants, formed in a region of the vocal tract where true fricatives are very difficult to produce.

In the human voice, lip retraction as in smiling can be associated with high fundamental (F₀) and formant frequencies. The aim of this study was to investigate under naturalistic conditions the cross-species generality of the frequency code hypothesis and related orofacial correlates in F₀. Digital spectral, spectrographic, and cinegraphic measurements were made of spontaneous chimpanzee vocalizations and orofacial movements produced and recorded in the field. A significant decline in F₀ was found in submissive scream-to-aggressive-waahbark transitions as predicted by the frequency code. Teeth and lip opening distances during sounds were positively correlated with their duration, F₀, frequency rise and tempo. These positive correlates and a trivariate regression between orofacial opening and F₀ give support to the coordination of these appeasing facial and vocal features proposed in the frequency code hypothesis.