Modelling the perception of English F0 scaling in a segmental context

Paper presented at ETAP 2 in Montreal:

Barnes, Jonathan, Alejna Brugos, Nanette Veilleux, & Stefanie Shattuck-Hufnagel. 2011. Modelling the perception of English F0 scaling in a segmental context. Experimental and Theoretical Advances in Prosody 2, Montreal, Canada. [pdf of abstract]

Voiceless intervals and perceptual completion in F0 contours: Evidence from scaling perception in American English

Paper from the special session at ICPhS XVII, “Shapes and Tones – Towards a More Holistic Perspective in Intonation Research”:
Jonathan Barnes, Alejna Brugos, Nanette Veilleux & Stefanie Shattuck-Hufnagel. (2011). Voiceless Intervals and Perceptual Completion in F0 Contours: Evidence from Scaling Perception in American English. ICPhS 17, Hong Kong. [pdf]

Abstract:
Intonation models describing F0 alignment and scaling in terms of peak and valley localization can face challenges when F0 contours are interrupted (e.g., during voiceless segments). It is often assumed that some form of perceptual completion or “filling in” of such intervals occurs that resolves these issues. This study uses the perceived scaling of High pitch accents both with and without missing peaks due to F0 gaps to adjudicate between three possible accounts of how speakers treat missing F0 in intonation perception. Results provide strong evidence against both extrapolation and interpolation across the missing region, supporting instead the hypothesis that listeners simply ignore these regions. This suggests that a non-turning-point-based model, such as TCoG, should be considered as an alternative to standard target-and-interpolation models.

TCoG preprint: “Tonal Center of Gravity: A global approach to tonal implementation in a level-based intonational phonology”

Jonathan Barnes, Nanette Veilleux, Alejna Brugos, and Stefanie Shattuck-Hufnagel. (Forthcoming). “Tonal Center of Gravity: A global approach to tonal implementation in a level-based intonational phonology.” Laboratory Phonology. [pdf]

Abstract

Recent evidence that pitch-movement shape can influence perceived alignment of rising (LH) pitch accents in several languages appears to challenge the well-established level-based approach to intonation embodied in the AM model, wherein it is typically assumed that the alignment and scaling of well- defined turning points (TPs) in the F0 contour are the primary phonetic correlates of contrastive accent category. Here we present the results of 2 experiments, arguing that a new approach to tonal implementation succeeds in reconciling these apparent contradictions. This approach, based on the notion of a perceptual reference point called Tonal Center of Gravity (TCoG), treats information about contour shape and TP-localization not in ‘either-or’ terms, but rather as two sets of cues working in a fundamentally synergistic way toward a single perceptual end: the alignment and scaling of TCoG. Experiment 1 shows that TCoG-based models can perform better at distinguishing productions of English L+H* and L*+H pitch accents than comparable TP-only-based models; Experiment 2 shows that TCoG is more robust than TP-only-based models to ambiguities in TP localization commonly encountered in F0 signals from natural speech. TCoG is shown to capture key insights of movement-based approaches to intonation, without abandoning the central advantages of level-based approaches like AM.

The effect of global F0 contour shape on the perception of tonal timing contrasts in American English intonation

Jonathan Barnes, Nanette Veilleux, Alejna Brugos and Stefanie Shattuck-Hufnagel. (2010). The effect of global F0 contour shape on the perception of tonal timing contrasts in American English intonation, Speech Prosody 2010, 100445: 1-4. [pdf]

Abstract:
Results from an ABX perception task involving the contrast between default- and late-timed pitch accents ((L+)H* and L*+H) in American English intonation demonstrate that pitch movement curvature, in addition to turning-point alignment, plays a role in determining listener categorization. A model based on Tonal Center of Gravity, effectively integrating both F0 turning-point and global contour-shape information, is shown to provide a better account of these results than can a model based on turning-points alone. Results suggest further that additional factors, such as scaling of the pitch accent in the frequency domain, may also play a role.

Perceptual Robustness of the Tonal Center of Gravity for Contour Classification

Poster from the September, 2009 Workshop on Prosody and Meaning, Barcelona:

“Perceptual Robustness of the Tonal Center of Gravity for Contour Classification” by Nanette Veilleux, Jon Barnes, Stefanie Shattuck-Hufnagel and Alejna Brugos [pdf of poster] [pdf of abstract]

Alternatives to F0 turning points in American English intonation

Poster from the November 2008 ASA meeting:
“Alternatives to F0 turning points in American English intonation,” by Jonathan Barnes, Nanette Veilleux, Alejna Brugos and Stefanie Shattuck-Hufnagel [pdf of poster]

Abstract:
Since the inception of the autosegmental‐metrical approach to intonation (Bruce 1977, Pierrehumbert 1980, Ladd 1996), the location and scaling of f0 turning points have been used to characterize phonologically distinct f0 contours in various languages, including American English. This approach is undermined, however, by the difficulty listeners experience in perceiving differences in turning point location. Numerous studies have demonstrated either listener insensitivity to changes in turning point location or the capacity for other aspects of contour “shape” to override turning‐point alignment for contour identification (Chen 2003, D’Imperio 2000, Niebuhr 2008). Even labelers with access to visual representations of the f0 encounter similar challenges. By contrast, a family of related measurements using area under the f0 curve to quantify differences in contour shape appear more robust. For example, a measure of the synchronization of the center of gravity of the accentual rise with the boundaries of the accented vowel yields 93.9% correct classification in a logistic regression model on a data set of 115 labeled utterances differing in pitch accent type. (L*+H L+H* in ToBI terminology). This classification proceeds entirely without explicit reference to the turning points (i.e., beginning of rise, peak) traditionally used to characterize this distinction.

Speech Prosody 2012 paper: The auditory kappa effect in a speech context

Preprint of Brugos, Alejna & Barnes, Jonathan. (2012). “The auditory kappa effect in a speech context.” Spech Prosody, Shanghai, China. [pdf]

CUNY 2012 poster: Pitch trumps duration in a grouping perception task

Here is the poster for Brugos, Alejna & Barnes, Jonathan (2012). “Pitch trumps duration in a grouping perception task,” 25th Annual CUNY Conference on Human Sentence Processing, New York, NY. March, 2012.

kappa-grouping-poster-031012

For the full-sized poster pdf, click here: brugos-barnes-CUNY2012.

Welcome to Prosody Lab

This space will be used to share publications and research news from the collaborations of:
Jonathan Barnes (Boston University)
Alejna Brugos (Boston University)
Stefanie Shattuck-Hufnagel (MIT)
Nanette Veilleux (Simmons College)