Developmental Psychology 1997, MM. 33, No. 1,3-11 Copyright 1997 by the American Psychological Association, Inc. 0012-l649/97/$3.00 Newborns Discriminate the Rhythm of Multisyllabic Stressed Words Alessandra Sansavini University of Bologna Josiane Bertoncini Laboratoire de Sciences Cognitives et Psycholinguistique, Centre National de la Recherche Scientifique Giuliana Giovanelli University of Bologna Three experiments were run to test whether newborns were able to discriminate different stress patterns in multisyllabic stressed Italian words that varied both in consonants and in number of syllables. A high-amplitude sucking procedure was adopted in which the experimental group heard 2 sets of stimuli alternating minute by minute, whereas the control group heard only a single set of stimuli. The results showed that stress patterns were discriminated in 2 disyllabic phonetically unvaried words (Experiment 1), in 2 trisyllabic consonant-varied words (Experiment 2), and in 2 sets of disyllabic words varied in consonants within and between words (Experiment 3). The alternation procedure proved to be suitable for examining newboms' abilities of discrimination and categorization. It also lowered the participants* rejection rate compared with the classic habituation procedure. The present results suggest that newborns are sensitive to words' rhythm, as carried by stress patterns, and that this prosodic information is salient even in the presence of substantial consonant variation. Studies on newborns and very young infants have shown that they are sensitive to the global prosody of natural speech. Newborns discriminate and prefer the mother's voice to other female voices (DeCasper & Fifer, 1980). The same preference has been found in 6-week-old infants as long as mothers' utter- ances are correctly intonated (Mehler, Bertoncini, Barriere, & Jassik-Gerschenfeld, 1978). Newborns as well as 2-month-olds also discriminate and prefer the maternal language compared with a foreign language (Mehler et al., 1988; Moon, Cooper, & Fifer, 1993), and they prefer a female voice to a male voice or a musical phrase (Giovanelli 1991; Giovanelli et al., 1990). Moreover, newboms (Cooper & Aslin, 1990) as well as 2-, 4-, Alessandra Sansavini and Giuliana Giovanelli, Department of Psy- chology, University of Bologna, Bologna, Italy; Josiane Bertoncini, La- boratoire de Sciences Cognitives et Psycholinguistique, CNRS, Paris, France. This research was supported by Italian CNR (National Council of Research) Grant 924561.08 and University of Bologna Grant 9200291. We thank Professors Marino Bosinelli, George Butterworth, and Na- than Fox and the three anonymous reviewers for their thoughtful and helpful comments; Professors GianPaolo Salvioli and Paola DallaCasa and the obstetricians of Bologna S. Orsola Hospital for the possibility of testing newborns at the hospital and the parents who, along with their infants, took part in the experiments; Daniele Maurizzi, Jean-Luc Manguin, and Michel Dutat for their technical assistance; Caroline Floc- cia for informatic suggestions; and Britte von Ooijen for reading the paper. Correspondence concerning this article should be addressed to Ales- sandra Sansavini, Department of Psychology, University of Bologna, Viale Berti Pichat 5,40127, Bologna, Italy. Electronic mail may be sent via Internet to asansavini@psibo.unibo.it. 5-, 1-, and 9-month-old infants (Pegg, Werker, & McLeod, 1992; Werker & McLeod, 1989) presented with infant-directed (ID) and adult-directed speech prefer to listen to ID speech, which emphasizes such prosodic characteristics as intonation, pauses, stress, tone, and duration of vowels (Bsrnald, 1985). The preference for the prosody of the maternal language be- comes more specific at about 6 months. At this age, infants discriminate and prefer to listen to sequences of words of the maternal language rather than to those of a foreign language when the two languages actually differ in their global prosody, whereas this preference appears only at 9 months when the two languages mostly differ in their phonetic and phonotactic properties (Jusczyk, Friederici, Wessels, Svenkerud, & Jusczyk, 1993). Moreover, 7- to 10-month-old infants prefer to listen to clauses of the maternal language in which artificial pauses are inserted between rather than within clauses (Hirsh-Pasek et al., 1987), and 9-month-old infants prefer to listen to phrases of the maternal language in which artificial pauses are inserted between rather than within phrases (Jusczyk, Hirsch-Pasek^ et al., 1992). It thus appears that, in their first months of life, infants pay attention to and discriminate the global prosody of speech and become attuned to the prosodic patterns of the mater- nal language. This tuning also appears in their first linguistic productions; 13-month-old French infants produce more length- ened final syllables and more ascending intonations than age- matched American infants (Levitt & Wang, 1991). These same characteristics have been found in 18-month-old French infants' productions, whereas age-matched Japanese infants produced more descending intonations and did not lengthen final syllables (Halle\ Boysson-Bardies, & Vihman, 1991). One can question whether the sensitivity to the prosodic struc- ture of speech can help infants to segment speech into words,