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.