An official website of the United States government
The Autosegmental-Metrical model of American English distinguishes three pitch accents with rising F0 trajectories (H*, L+H*, L*+H), differing in peak alignment and presence vs. absence of a low pitch marking the rise onset. Empirical studies report additional distinctions in the dynamics and scaling of the F0 rise, raising the question of which properties best capture variation among accents. We use functional principal components analysis (FPCA) to examine dynamic properties of accentual F0 trajectories in data from an intonation imitation experiment. F0 trajectories from 70 speakers producing rising accents on the phrase-final (nuclear) accented word were submitted to FPCA. The first three PCs account for 95% of variation in F0 trajectories and each shows significant differences between the three rising accents. Variation in PC1 primarily relates to differences in the overall F0 level of the trajectory, PC2 captures differences in rise shape (scooped vs. domed rise) and PC3 captures fine variation from a following Low phrase accent. Alignment distinctions are distributed across all three PCs. Examination of individual speakers shows all use PC1 and PC2 to some degree to distinguish rising accents, with no trading relations. Rises are variously implemented through level or shape distinctions, to varying degrees across individuals
more »
« less
American English pitch accent dynamics: A minimal model
What is the minimal mathematical model that can generate the F0 trajectories for a system of pitch accents? In this work, we propose a nonlinear coupled dynamical systems theory of American English pitch accents with a single basic parameter. As that parameter increases, F0 profiles for different pitch accents are generated. The terms in the differential equation are based on a novel dynamical analysis of a large database of F0 productions in terms of measurements of F0 peak, peak velocity, and the time to achieve peak velocity. We describe the basic dynamical properties of pitch accents in our database and argue for the proposed model as the simplest one that realizes all the major dynamic F0 properties of the pitch accent system. We argue that the proposed model describes both abstract phonological and concrete phonetic aspects of the system.
more »
« less
- Award ID(s):
- 1944773
- PAR ID:
- 10497324
- Editor(s):
- Radnick, S.; Volin, J.
- Publisher / Repository:
- International Phonetic Association: London
- Date Published:
- Journal Name:
- Proceedings of the International Congress of Phonetic Sciences
- ISSN:
- 2412-0669
- ISBN:
- 978-80-908-114-2-3
- Format(s):
- Medium: X
- Location:
- Prague
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
In Autosegmental-Metrical models of intonational phonology, different types of pitch accents, phrase accents, and boundary tones concatenate to create a set of phonologically distinct phrase-final nuclear tunes. This study asks if an eight-way distinction in nuclear tune shape in American English, predicted from the combination of two (monotonal) pitch accents, two phrase accents, and two boundary tones, is evident in speech production and in speech perception. F0 trajectories from a large-scale imitative speech production experiment were analyzed using bottom-up(k-means) clustering, neural net classification, GAMM modeling, and modeling of turning point alignment. Listeners’ perception of the same tunes is tested in a perceptual discrimination task and related to the imitation results. Emergent grouping of tunes in the clustering analysis, and related classification accuracy from the neural net, show a merging of some of the predicted distinctions among tunes whereby tune shapes that vary primarily in the scaling of final f0 are not reliably distinguished. Within five emergent clusters, subtler distinctions among tunes are evident in GAMMs and f0 turning point modeling. Clustering of individual participants’ production data shows a range of partitions of the data, with nearly all participants making a primary distinction between a class of High-Rising and Non-High-Rising tunes, and with up to four secondary distinctions among the non-Rising class. Perception results show a similar pattern, with poor pairwise discrimination for tunes that differ primarily, but by a small degree, in final f0, and highly accurate discrimination when just one member of a pair is in the High-Rising tune class. Together, the results suggest a hierarchy of distinctiveness among nuclear tunes, with a robust distinction based on holistic tune shape and poorly differentiated distinctions between tunes with the same holistic shape but small differences in final f0. The observed distinctions from clustering, classification, and perception analyses align with the tonal specification of a binary pitch accent contrast {H*, L*} and a maximally ternary {H%, M%, L%} boundary tone contrast; the findings do not support distinct tonal specifications for the phrase accent and boundary tone from the AM model.more » « less
-
Phrase-level prosodic prominence in American English is understood, in the AM tradition, to be marked by pitch accents. While such prominences are characterized via tonal labels in ToBI (e.g. H*), their cues are not exclusively in the pitch domain: timing, loudness and voice quality are known to contribute to prominence perception. All of these cues occur with a wide degree of variability in naturally produced speech, and this variation may be informative. In this study, we advance towards a system of explicit labelling of individual cues to prosodic structure, here focusing on phrase-level prominence. We examine correlations between the presence of a set of 6 cues to prominence (relating to segment duration, loudness, and non-modal phonation, in addition to f0) and pitch accent labels in a corpus of ToBI-labelled American English speech. Results suggest that tokens with more cues are more likely to receive a pitch accent label.more » « less
-
Many problems in the study of dynamical systems—including identification of effective order, detection of nonlinearity or chaos, and change detection—can be reframed in terms of assessing the similarity between dynamical systems or between a given dynamical system and a reference. We introduce a general metric of dynamical similarity that is well posed for both stochastic and deterministic systems and is informative of the aforementioned dynamical features even when only partial information about the system is available. We describe methods for estimating this metric in a range of scenarios that differ in respect to contol over the systems under study, the deterministic or stochastic nature of the underlying dynamics, and whether or not a fully informative set of variables is available. Through numerical simulation, we demonstrate the sensitivity of the proposed metric to a range of dynamical properties, its utility in mapping the dynamical properties of parameter space for a given model, and its power for detecting structural changes through time series data.more » « less
-
Abstract Whereas some authors claim that the distribution of prenuclear accents in English largely follows from rhythmic and other non-informational considerations, other authors report a small but meaningful effect of prenuclear accents on the interpretation of sentences. In this paper we report on an experiment where native English speakers were asked to repeat stimulus sentences with one of three different accentual patterns on a word in sentence-initial prenuclear position: unaccented, with a high pitch accent on the syllable with primary stress or with a high accent on an earlier syllable with secondary stress. Participants were moderately successful in reproducing the intonational patterns. The early high accent pattern was reproduced particularly well. An automatic classification algorithm nevertheless produced four clusters of contours, instead of the three patterns present in the stimuli. Two distinct contours were used to signal the presence of a high tone before the syllable with primary stress. We conclude that the early high accent pattern is a strong attractor in imitations, but it was implemented with F0 trajectories that would be analyzed as phonologically different, suggesting an equivalence class of prenuclear contours. We also note a preference for rhythmic anchoring in the prenuclear position.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Proceeding:
- The DOI is not currently available.
