Melodic versus intonational coding of communicative functions: A comparison of tonal contours in infant-directed song and speech.

Abstract

ABSTRACT - Global intonational contours of infantdirected speech are said to serve effective communicative functions. For example, steep rising contours are thought to arouse an infant while smoothly falling contours are thought to be soothing. Several researchers (e.g., Cordes, 2005; Papousek, 1996; Unyk, Trehub, Trainar, & Schellenberg, 1992) proposed that the melodic contours in nursery songs should fallow the same communicative principles as in speech. In this study, melodic and intonational contours in play contexts were compared in three languages in order to determine 1) whether infant-directed speech and song are similar in the composition of their typical contours, and 2) whether there are differences across languages. Evidence from soothing contexts is also taken into account. The material was collected from 43 German-, Frenchand Russian-speaking parents singing or speaking to their 2- to 12- month-old infants. Tonal contour types in each register were assessed adopting protocols based on Cordes (2005). The results confirm the similarity between infant-directed speech and song in play contexts, but some differences occur in soothing contexts. Languagespecific patterns are discussed, and it is put forward that it would be valuable to intensify research into the language-specific basis of infant-directed communication. KEYWORDS - Infant-directed speech, song, contour forms, communicative function In the presence of an infant, adults often unconsciously change their way of talking and singing. They slow down in tempo, use a higher overall pitch level, show more pitch variability, make more pauses and repeat their utterances (overview in Cruttenden, 1994; Trehub, 2003). In their first year of life, infants clearly prefer to listen to infant-directed speech (or motherese) and song than to adult-directed speech and song (Cooper, Abraham, Berman, & Staska, 1997; Fernald, 1984; Fernald & Kuhl, 1987; Nakata & Trehub, 2004; Trainor, 1996; Trehub & Trainor, 1998). Infants' preference for infant-directed speech is thought to be mostly due to the tonal structure of the signal (Fernald & Kuhl, 1987): adults use a wider frequency range, a higher speech register and salient tonal contours when addressing children (Fernald & Simon, 1984; Fernald et al., 1989; Gavrilova, 2001; Stern, Spieker, & MacKain, 1982). Infant-directed songs are also sung at a higher pitch level (Trainor & Zacharias, 1998), in a smiling tone and with more jitter and shimmer in the voice (Trainor, 1996; Trainor, Clark, Huntley, & Adams, 1997), which might be due to a higher emotional involvement of the singer (Trehub & Trainor, 1998). Fernald (1989), Papousek (1996), and Papousek, Papousek, and Symmes (1991) showed that there is a narrow inventory of tonal contour types in infant-directed speech used by parents to fulfill distinct communicative functions. Rising contours encourage a turn or elicit attention (especially at the age of 2 and 3 months, see Henning, Striano, and Lieven, 2005), bell-shaped contours close a turn or signal approval, steeply falling contours with abrupt onsets are used for warnings, disapproval and prohibitions whereas smoothly falling contours soothe and comfort the infant (see Figure 1). These functions were initially taken to be cross-linguistic universale (Grieser & Kuhl, 1988; Papousek et al., 1991), though further research showed some variations in tonal features and in the frequency of contour types across language and cultural context, sex and age of the infant (Kitamura & Burnham, 2003; Kitamura, Thanavishuth, Burnham, & Luksaneeyanawin, 2001; Lam & Kitamura, 2006; Rabain-Jamin & Sabeau-Jouannet, 1997). In the first year of life, infants attend particularly to the global shape of tonal/melodic contours in speech and song (Fernald & Kuhl, 1987; Trehub, Bull, & Thorpe, 1984). Thus, tonal contours with communicative functions might help infants to establish a first semantic-pragmatic relation between phonetic form and global referential meaning. …