Pitch contour

Since co-expressive gesture and speech typically overlap in time (McNeill, 1992), gestures that are synchronized with these lexemes are likely to represent location, motion, and caused motion. We analyzed only those gestures that temporally overlap with the breath group that contained one of the lexemes in Table 5.1 (a breath group was delineated by a pause, or a break in pitch contour, or an abrupt shift in speech rate). 

Intonation is sometimes used as a synon for prosody, and as such includes prominence and phrasing as just described. Here we use a more narrow definition in which intonation is the systematic use of pitch for communication. Often we describe intonation with reference to the pitch contour or the FO contour, which is the pattern of pitch/FO variation over an utterance" ... 

D Alessandro, C., and Mertens, P. Automatic pitch contour stylization using a model of tonal perception. In Computer Speech and Language (1995). 

Good Performers Know Their Audience Identification and Characterization of Pitch Contours in Infant- and Foreigner-Directed Speech... 

The acoustic and phonetic characteristics of this IDS are well recognized, and seem to be universal (e.g. Grieser and Kuhl, 1988 Kuhl et al., 1997 Kuhl, 2000). It has been found that IDS is characteristically higher in pitch than adult-directed speech (ADS), and contains exaggerated pitch contours, shorter utterances, longer pauses and hyperarticulation of vowels (Stem et al., 1983 Femald and Simon 1984 Andruski and Kuhl, 1996 Kuhl et al., 1997 Trainer et al., 2000 Burnham et al., 2002). 

A major impediment to pitch contour analysis is that pitch contour shape has traditionally been analysed qualitatively using human raters (e.g. Femald and Simon, 1984). There have recently been several attempts to find reliable quantitative methods, but no single approach has emerged as either simple in its execution or capable of being applied to a wide variety of speech types. For instance, Trainor et al. (2000) used measurements of pitch values at prespecified points within a contrived stock phrase. This approach was unable to provide a sensitive characterization of pitch contours. By contrast, Moore et al. (1994) successfully applied mathematical modelling to the problem. Then-approach would potentially allow a wide variety of speech types to be addressed, but the complexity of their approach seems to have prevented its wide acceptance within psychology. 

A pre-existing data-set of infant-, foreigner- and adult-directed speech samples in WAV format formed the basis of the data-set (Knoll and Uther, 2(X)4). Pitch contours were randomly selected from these groups and then modified to a standardized format that could be used for the DAISY, EA and qualitative conditions. The extracted pitch contours comprised the specific target words sheep , shark and shoe, which were chosen because they had been found to be prosodicaUy highlighted in IDS and FDS in a previous study (KnoU and Uther, 2004). A total of 167 pitch contours (IDS = 60, ADS = 53, FDS = 54) were extracted from these words. 

Pitch contour extraction was achieved using the freely available speech analysis program, Praat 4.1.19 (Boersma and Wernicke, 2004). The pitch range for the extraction was set at a floor of 100 Hz and a ceiling of 600 Hz (recommended setting in Praat 4.1.19 for fanale voices). It should be noted that although the whole word was used for the extraction process, only visible pitch contours were extracted (which often do not encompass whole words). The smooth function was then used to smooth the contours (at lO-Hz bandwidth). This is a standard procedure to obtain... 

FIGURE 18.1 Comparison of pitch contours in ADS (left) and IDS (right). Note that the duration is very different, bnt that the actual pitch contours are drawn in the same size. Using the set window of 0.700 avoids this distortion as a durational pitch contour of 0.237 would be drawn relative to the 0.700 seconds window. 

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