A focus intonational morpheme in European Portuguese: Production and perception

Production studies of the intonational signalling of focus in European Portuguese (EP) have shown that focus is expressed by a specific pitch accent type, thus revealing a systematic contrast between nuclear accents associated with different meanings. In declarative utterances, the contrast between the neutral/broad focus reading and the narrow/contrastive focus reading is essentially realized as an alignment difference: H+L* (neutral accent) and H*+L (focus accent). A pilot perceptual study using natural stimuli has shown that subjects are able to distinguish between members of neutral/focus minimal pairs and to match them to the appropriate production context. However, the perception of the contrast found in production has not yet been investigated in detail. The present paper revisits the production contrast and investigates its categorical nature using a multiple methodology approach that resorts to semantically motivated tasks. Several experiments tested whether differences in F0 peak and valley alignment would trigger a perceptual change from one meaning to the other, and whether the alignment differences pattern alike in stimuli based on a neutral and a focus sentence. In Experiment 1, stimuli were classified in a context-matching identification task. In Experiment 2, participants rated appropriateness of stimulus to context in a semantic scaling task. Finally, in Experiment 3, pairs of stimuli were discriminated in a context-matching discrimination task. The results of the three experiments provide converging evidence for the distinction between H+L* and H*+L. Moreover, they support the claim that the neutral/focus accent distinction is primarily an alignment contrast phonologically encoded at the pitch accent level. These findings have implications for the understanding of the nature of intonational contrasts, and the discussion about the approaches and methods to define prosodic categories.