The role of *perception in defining tonal targets and their alignment.

摘要

Tonal targets can be defined in terms of two-dimensions, i.e., "alignment" and "scaling", where alignment specifies the exact temporal implementation of tonal highs (H) and lows (L) relative to structural elements (such as syllables and morae) and their segments. Alignment patterns might be constrained by various linguistic factors, such as phonological as well as phonetic factors. Among the phonetic constraints, one finds facts about the perception of pitch and time, both for speech and for non-speech stimuli.;This thesis investigates the role of alignment in determining tonal target perception for Neapolitan yes/no question and (narrow focus) statement contours. These contours are characterized by a melodic rise-fall, analyzed here as a sequence of a LH pitch accent plus a HL phrase tone. In most cases, this configuration is acoustically realized as a sequence of three tonal targets, LHL, due to "merging" of the H tone sequence in nuclear position.;A read speech corpora, produced by two speakers of Neapolitan Italian, was first analyzed to acoustically characterize tonal targets in both yes/no questions and narrow focus statements, with target words differing in syllable structure and segmental environment. Later, a set of resynthesized stimuli was created, which constituted the basis for the perception experiments. Results show that, when the LHL tonal targets for the entire rise-fall, are displaced later in time, more questions are identified. Also, the sole alignment modification of the first or the second L determines different question responses. The results also suggest that f0 height has a minor role in signaling pitch accent differences, while rise and fall slope have no impact. Additionally, when the shape of the peak in the rise-fall is modified (creating a "plateau"), more questions are perceived. Similar results were also found when the stimuli were presented to American English listeners, which suggests a universal use of alignment and a psychoacoustic effect of perceived target displacement due to peak shape. Finally, syllable structure manipulations did not shift crossover boundaries for Neapolitans, while base stimulus modality did. In sum, this thesis proposes that temporal alignment must shape phonological systems of intonational contrast, both within and across languages.