Publications

Abstract

It has been claimed that Dutch listeners use suprasegmental cues (duration, spectral tilt) more than English listeners in distinguishing English word stress. We tested whether this asymmetry also holds in production, comparing the realization of English word stress by native English speakers and Dutch speakers. Results confirmed that English speakers centralize unstressed vowels more, while Dutch speakers of English make more use of suprasegmental differences.

Abstract

Sentences with contrastive intonation are assumed to presuppose contextual alternatives to the accented elements. Two cross-modal priming experiments tested in Dutch whether such contextual alternatives are automatically available to listeners. Contrastive associates – but not non- contrastive associates - were facilitated only when primes were produced in sentences with contrastive intonation, indicating that contrastive intonation makes unmentioned contextual alternatives immediately available. Possibly, contrastive contours trigger a “presupposition resolution mechanism” by which these alternatives become salient.

Abstract

Listeners heard an ambiguous /f-s/ in nonword contexts where only one of /f/ or /s/ was legal (e.g., frul/*srul or *fnud/snud). In later categorisation of a phonetic continuum from /f/ to /s/, their category boundaries had shifted; hearing -rul led to expanded /f/ categories, -nud expanded /s/. Thus phonotactic sequence information alone induces perceptual retuning of phoneme category boundaries; lexical access is not required.

Abstract

We report four experiments in which English and Italian monolinguals detected clicks in continous speech in their native language. Two of the experiments used an off-line location task, and two used an on-line reaction time task. Despite there being large differences between English and Italian with respect to rhythmic characteristics, very similar response patterns were found for the two language groups. It is concluded that the process of click detection operates independently from language-specific differences in perceptual processing at the sublexical level.

Abstract

In the absence of explicitly marked cues to word boundaries, listeners tend to segment spoken English at the onset of strong syllables. This may suggest that under difficult listening conditions, speech should be easier to recognize where strong syllables are word-initial. We report two experiments in which listeners were presented with sentences which had been time-compressed to make listening difficult. The first study contrasted sentences in which all content words began with strong syllables with sentences in which all content words began with weak syllables. The intelligibility of the two groups of sentences did not differ significantly. Apparent rhythmic effects in the results prompted a second experiment; however, no significant effects of systematic rhythmic manipulation were observed. In both experiments, the strongest predictor of intelligibility was the rated plausibility of the sentences. We conclude that listeners' recognition responses to time-compressed speech may be strongly subject to experiential bias; effects of rhythmic structure are most likely to show up also as bias effects.

Abstract

Previous research has shown that listeners use the prosodic structure of utterances in a predictive fashion in sentence comprehension, to direct attention to accented words. Acoustically identical words spliced into sentence contexts arc responded to differently if the prosodic structure of the context is \ aricd: when the preceding prosody indicates that the word will he accented, responses are faster than when the preceding prosodv is inconsistent with accent occurring on that word. In the present series of experiments speech hybridisation techniques were first used to interchange the timing patterns within pairs of prosodic variants of utterances, independently of the pitch and intensity contours. The time-adjusted utterances could then serve as a basis lor the orthogonal manipulation of the three prosodic dimensions of pilch, intensity and rhythm. The overall pattern of results showed that when listeners use prosody to predict accent location, they do not simply rely on a single prosodic dimension, hut exploit the interaction between pitch, intensity and rhythm.

Abstract

Speech production is constrained at all levels by the demands of speech perception. The speaker's primary aim is successful communication, and to this end semantic, syntactic and lexical choices are directed by the needs of the listener. Even at the articulatory level, some aspects of production appear to be perceptually constrained, for example the blocking of phonological distortions under certain conditions. An apparent exception to this pattern is word boundary information, which ought to be extremely useful to listeners, but which is not reliably coded in speech. It is argued that the solution to this apparent problem lies in rethinking the concept of the boundary of the lexical access unit. Speech rhythm provides clear information about the location of stressed syllables, and listeners do make use of this information. If stressed syllables can serve as the determinants of word lexical access codes, then once again speakers are providing precisely the necessary form of speech information to facilitate perception.