Vocalizations of Infants_definitivo

International Journal of Music Education

29(3) 241 –256© The Author(s) 2011

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DOI: 10.1177/0255761411408507ijm.sagepub.com

Vocalizations of infants (9–11 months old) in response to musical and linguistic stimuli

João Reigado, António Rocha and Helena RodriguesCESEM, Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa, Portugal

AbstractThis study analyzes infant vocal responses in order to determine whether infants exposed to both linguistic and musical stimuli exhibit different types of vocalizations in response to those two different kinds of stimulation. Twenty-one infants, from 9 to 11 months of age, were observed in four weekly sessions over the period of a month. Each session consisted of two presentations: musical, in which the experimenter sang, and linguistic, in which the experimenter narrated poems. Infants’ vocalizations were recorded and submitted to aural and acoustic analysis. The results showed that infants’ vocalizations in response to both presentations displayed different characteristics of duration and vocal extension. Infant vocalizations in response to musical stimuli consisted predominantly of isolated sounds, with a high percentage of first and third steps of the scale of the musical stimuli as well as a predominance of melodic intervals and contours outlining important scalar steps of the stimuli. Descending intervals were also a characteristic of infant vocal production in response to musical stimuli.

Keywordsinfants, linguistic stimuli, musical stimuli, singing, vocalizations

Introduction

Recent studies have highlighted the presence of musical cognitive activity since birth. Since the measurement of musical cognition in newborns through behavioral techniques is difficult, inves-tigators have been using techniques of measuring electrical brain responses (Hefer, Weintraub & Cohen, 2009; Honing, Ladinig, Háden & Winkler, 2009) and analyzing near-infrared spectros-copy (NIRS) (Kotilahti et al., 2010). Despite the fact that these studies addressed different research

Corresponding author:João Pedro Reigado, CESEM, Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa, 1069-061 Lisboa, Portugal. Email: [email protected]

Article

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questions – the first two studies dealt with the search for neurological correlates which could confirm newborns’ musical cognition at different levels while the third investigated the lateraliza-tion of speech and music responses of newborns – they all concluded that some musical capacities are already functional at birth.

In the first few months of life infants are already able to produce sounds and direct them inten-tionally to adults in their vicinity. Infants quickly notice that these early vocalizations attract their mothers’ interest, reinforcing communication between them (H. Papousek, 1996; M. Papousek, 1996; Van Puyveld et al., 2010). Even though there has been no doubt about the communicative value of these first vocalizations, discussion of their nature has occupied researchers for years.

According to many authors, vocalizations with musical content are present in the infant’s first years of life. To Dowling (1999), Fox (1983), Gordon (2000), Moog (1976), Tafuri & Villa (2002) and Welch (1994), who based their findings on observation of infants in natural settings, it seems evident that an infant’s vocalizations contain musical features similar to those found in the musical culture of its environment. Dowling (1999) showed that at approximately two years of age an infant’s songs usually consist of the repetition of a single brief melodic phrase and that with age complexity increases by the addition of more phrases.

One of the first studies to describe systematically the vocal behavior of babies was done by Moog in 1976 (Hargreaves, 2001). Moog distinguished between non-musical and musical bab-bling and claimed that the former appears first in preparation for language acquisition, while the latter is a specific reaction to the music heard by the child. According to this author, the earliest song babblings begin at 4–6 months, just after overt movements to music. These vocal productions are mostly descending melodic lines, “moving in micro-intervals smaller than a minor second” (Moog, 1976, p. 40). Fox (1983) also found a high percentage (82%) of descending contours in her study of pitch range and contour in the vocal productions of infants.

Research on linguistics has already produced a body of work concerned with speech acquisi-tion, in both perception and production. Several researchers (e.g. Ingram, 1989; Oller, 1980; Stark, 1981) have proposed stages in the development of speech production. Despite differences among their assumptions, they share a common view of the course of speech production: (1) reflexive sound making; (2) cooing and laughter; (3) expansion/vocal play; (4) reduplicated babbling; (5) variegated babbling/proto-words; (6) referential words.

With regard to perception and to sound/speech discrimination, it has been demonstrated that infants are sensitive to the female voice (Fernald & Simon, 1984), infant-directed speech (Cooper & Aslin, 1990; Fernald, 1989, 1991; Pegg, Werker & McLeod, 1992), rhythmic characteristics of prosody (Mehler et al., 1988; Nazzi, Bertoncini, & Mehler, 1998) and sound sequences that are more frequent in their native language (Kuhl, 1991; Morgan & Saffran, 1995). The ability to distinguish among stress patterns (Jusczyk, Friederici, Wessels, Svenkerud, & Jusczyk, 1993) is also present a few months after birth. It seems that during the development of speech perception, infants are sensitive to many extra-linguistic elements within an auditory context.

From the very beginning of life, musical elements even before phonetic elements seem to par-ticipate in the process of communication, playing an important role in the acquisition of linguistic capacities. Papousek stated that these musical elements may have biological origins and that they can be observed in adult interactions with babies already in the first weeks after birth (H. Papousek, 1996; M. Papousek, 1996).

Thus it is not surprising that babies are highly susceptible to music, especially infant-directed singing, a way of singing in which the adult adapts his performance in the presence of a baby (Longhi, 2009; Trainor, 1996; Trehub, 2003). Ilari & Sundara (2009) noted that babies prefer singing without instrumental accompaniment.

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Research on the development of listening skills has shown similarities between infants and adults, for instance in how children are able to group auditory events in much the same way as adults (Hannon & Trainor, 2007; Trehub & Thorpe, 1989).

Studies concerning infants’ and young children’s understanding of melodies have demonstrated the importance of melodic contour (Trehub, Bull, & Thorpe, 1984; Trehub, Thorpe & Morrongiello, 1985, 1987) and the discrimination of melodic and harmonic intervals (Schellenberg & Trehub, 1996a, 1996b), key relations (Trainor & Trehub, 1993, 1994), rhythm (Trehub & Thorpe, 1989), tone patterns (Schellenberg & Trehub, 1994), scale structure (Trehub, Schellenberg, Kamenetsky, 1999), western vs. nonwestern pitch and rhythmic organization (Ilari, 2002) and phrase structure (Krumhansl & Jusczyk, 1990).

Because infants have such powers of discrimination right from birth, they are clearly able to take advantage of musical stimulation. This is where music guidance sessions for newborns and infants have a vital role to play, not only in developing the perception of specific musical elements of the culture of origin (Gerry, Faux, & Trainor, 2010) but also in guiding the use of the singing voice. Studies by Adachi (1994, 2006) and Adachi, Nakata & Kotani (2002) demonstrate the importance of the musical environment in infant development, specifically in infants’ spontaneous responses to music and their motor development. Families in which there are frequent musical interactions between infants and caregivers are likely to see an increase in the number of musical responses, such as spontaneous singing and motor responses to music (Adachi, 1994, Kida & Adachi, 2008).

However, the sparse studies focused on the development of singing voice during the first two years of life – as, for example, Tafuri & Villa (2002) – have mainly highlighted the spontaneous productions of infants making little or no reference to comparison with spontaneous linguistic productions of infants. In order to have a complete overview, studies based on spontaneous infant productions need to be complemented with studies in which there is a referential model, paving the way for comparisons between singing acquisition and linguistic acquisition. Moreover, when comparing babies’ earliest vocalizations, it is difficult to identify those that are based on language as opposed to those based on music (Rocha, Reigado & Rodrigues, 2008; Rocha, Reigado, Silva & Rodrigues, 2009). As noted by Rodrigues (2005) and Rodrigues, Rodrigues and Nunes (2003), babies’ tendency to explore and imitate vocally makes it difficult to establish boundaries between musical and linguistic responses.

The intention of this study is to clarify questions concerning vocal production and the process of the acquisition of singing in infants. It aims to evaluate babies’ vocalizations in response to musical and linguistic stimuli. This study addresses two questions: (1) Are vocalizations produced after musical stimuli distinguishable from those produced after linguistic stimuli? (2) In the event that specifically musical vocalizations can be distinguished, what features does musical babbling exhibit in comparison with the specific musical stimuli that evoke it?

Method

Participants

Twenty-one infants (13 girls and 8 boys), aged 9–11 months (with a mean age of 10 months, 3 days) with their parents participated in this study. They were recruited through an announcement asking for volunteers, without compensation, to participate in four weekly sessions aiming to investigate infants’ behavior in response to music and language. The announcement was distributed in urban daycare centers, postpartum centers and pediatric clinics. Participants were not involved in musical


guidance sessions for infants or in any specific music program for families. There didn’t seem to be any practical differences in the musical life at the participants’ homes.

Materials

Three songs without words were used, differing in meter, tempo and tonality. The songs were chosen from The Early Childhood Music Curriculum: Experimental Songs and Chants without Words: Book One, by Gordon, Bolton, Hicks and Taggart (1993) (see Appendix A). Three poems for children were used as linguistic stimuli. They were chosen from Versos de fazer ó-ó by Letria (1999) (see Appendix B).

The sessions were taped using a Sony – ECM – 717 high-quality microphone. Recordings were stored and coded on an Apple iBook G4 computer. Amadeus II v3.8.4 (Hairer, 2005) software was used for segmentation of the vocalizations. The acoustic analysis was made with Praat software, version 4.4.04 (Boersma & Weenink, 2006).

Procedure

Infants were accompanied by a caregiver and individually exposed to both musical and linguistic stimuli through four weekly sessions. So, each infant was observed during four twenty-minute ses-sions once a week for a month. In each session, the infant and his/her caregiver sat on a colored carpet in front of the experimenter. A recording device collected infants’ vocalizations. Two peri-ods of stimulation (musical and linguistic) were used in order to elicit infant vocalizations. These periods were reversed from session to session. That is, if in a given week the sequence was first musical and then linguistic stimulation, in the following week the sequence was the opposite. The overall data collection period lasted 3 months.

The sessions were conducted as follows: the experimenter sang the first song in its entirety and then allowed the infant to respond. During this period, which should have lasted 3 minutes and 20 seconds, the experimenter further stimulated infant vocalizations by repeating some melodic patterns from the song and/or the entire song again. After this period, the experimenter presented the second song using the same procedure. This routine was also repeated for the third song.

The linguistic parts of the experimental sessions were conducted through an identical proce-dure, but using poems instead of songs. For both types of stimulation, infant-directed singing and infant-directed speech were used.

Sessions were recorded and infants’ vocal productions were collected and coded for further blind analysis. We collected a total of 93 vocalizations produced in response to linguistic stimulation and 104 in response to musical stimulation (N = 197). They were collected either after the initial full presentation of the stimulus (musical or linguistic) or after the follow-up interaction with melodic patterns from the musical stimulus or speech fragments taken from the words of the linguistic stimulus.

Aiming to answer the first question of this study, infant vocal responses to musical stimuli were compared to their responses to linguistic stimuli on two parameters: duration and extension.

For the analysis of duration, vocalizations were considered in their entirety, just as they arose in response to each stimulus. For the analysis of extension we obtained F0 for each infant’s vocalization and F0 for each experimenter’s vocal stimulus. These measurements were supported by spectrograms that were made for all vocalizations. Because of the nature of F0, vocalizations had to be submitted to segmentation. In this way, the total of 104 vocalizations produced during

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the musical stimulus yielded 146 elements and the total of 93 vocalizations produced during the linguistic stimulus yielded 104 elements (N = 250).

Besides the F0 acoustic analyses, the extension of each vocalization in response to musical and linguistic stimuli was studied through melodic analysis. For this, a range between minimum and maximum values was converted into a twelve-tone scale based on equal temperament, considering an isolated sound (which is assigned the value 0) as the minimum unit of extension.

To address the second question of this study, a comprehensive description of the vocalizations elicited by musical stimuli was carried out. For this analysis we considered the vocalizations in their entirety. The following categories were used to describe each vocalization: isolated sounds (a single vocalic sound with noticeable pitch), melodic intervals (two successive pitches in a vocalic motion – ascending or descending), melodic contours (more than two successive pitches or a glissando curve in a vocalic motion – ascending, descending or undulating in a similar tonal context to the stimulus), melodic exploration (vocalization in a tonal context different from the stimulus), and unrelated to the musical stimulus (other sounds such as crying and cooing).

Results

The average duration of the infants’ vocal production in response to the music was 1.60 seconds (SD = 0.32) ranging between 1.21 and 2.38 seconds. Conversely, the average duration of infants’ vocal production in response to the linguistic mode was 5.81 (SD = 0.96) ranging between 4.50 and 7.44 seconds.

Tables 1, 2 and 3 display data from a vocal extension analysis. Table 1 shows the extreme values (minimum and maximum) of the variable F0 in linguistic and musical modes both for the infants’ vocalizations and for the experimenter’s vocal stimulus.

Data show that F0 minimum values for infant vocalizations were similar for both modes. F0 maximum value for infants’ vocalizations was higher in the linguistic mode than in the musical one. F0 minimum value for experimenter vocal stimulus was higher for the musical than for the linguis-tic mode. F0 maximum value for experimenter vocal stimulus was higher for linguistic than for the musical mode. Experimenter vocal stimulus ranged from 92 Hz to 415 Hz. Infants’ vocalizations ranged from 283 Hz to 587 Hz. The amplitude of F0 values was greater in the linguistic mode than in the musical mode both for infant vocalizations and for the experimenter. In the linguistic mode, the amplitude of F0 values for infant’s vocalizations is 293 Hz; the amplitude of F0 values for experimenter’s vocal stimuli is 323 Hz. The difference between the two amplitudes is 30 Hz.

Table 1. Mean, standard-deviation and range for F0 infants’ vocalizations and for F0 experimenter’s vocal stimulus in each stimuli mode

Stimuli condition F0 (Hz)

M SD Range

Linguistic Infants 440.7 83.3 294-587 Exp 253.9 102.1 92-415Musical Infants 361.6 53.2 283-440 Exp 192.8 70.1 139-247


In the musical mode, the amplitude of F0 values for infant vocalizations is 157 Hz; the amplitude of F0 values for experimenter vocal stimulus is 108 Hz. The difference between the two amplitudes is 49 Hz.

Tables 3 and 4 show the number of infants’ vocalizations and the number of experimenter’s vocal stimuli in terms of the extension of each infant vocalization and each experimenter’s vocal stimuli, in both musical and linguistic modes, respectively. Extension was measured in semitones. In both tables, the total of occurrences is presented in raw scores and in percentages.

The tables show that in the linguistic mode infant vocalizations cover extensions between 0 and 25 semitones (m16) while experimenters’ vocal stimuli cover extensions between 0 and 38

Table 2. Frequency and Extensions of Infants’ Vocalizations and Frequency and Extension of Experimenter’s Vocal Stimuli in the Linguistic Mode (extension measured in semitones)

Vocal extension (semitones) in linguistic context

Stimuli (Experimenter)

Infant productions

0 1 2 3 4 5 6 7 8 9 12 13 14 15 16 17 25 N %

0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0.96 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0.96 2 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0.96 3 2 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 4 3.85 4 1 1 0 4 0 2 0 2 0 0 0 0 0 0 0 0 0 10 9.62 5 1 2 0 2 1 1 0 0 0 0 0 0 0 0 0 0 0 7 6.73 6 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 2 1.92 7 4 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 7 6.73 8 2 0 2 1 1 2 0 0 0 0 0 0 0 0 0 0 0 8 7.69 9 2 2 0 2 0 0 0 1 0 0 0 0 1 0 0 1 0 9 8.6510 0 0 1 1 0 1 0 0 2 0 0 0 0 0 0 0 0 5 4.8111 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1.9212 1 1 1 2 0 1 0 0 0 0 0 0 0 0 1 0 0 7 6.7313 0 1 1 2 0 0 0 0 0 0 0 0 0 0 0 0 1 5 4.8114 3 0 1 0 1 0 0 2 0 0 0 0 0 0 0 0 0 7 6.7315 0 0 3 0 0 0 0 0 0 0 0 0 0 0 1 0 0 4 3.8517 0 0 1 1 0 1 0 1 0 0 0 0 0 0 0 0 0 4 3.8518 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0.9619 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0.9620 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1.9221 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 3 2.8822 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1.9223 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 2 1.9224 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0.9625 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 2 1.9226 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 2 1.9229 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 2 1.9231 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0.9638 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0.96Totals 18 13 17 22 6 9 1 9 2 0 1 0 1 1 2 1 1 104 100.00% 17,3112,50 16,3521,15 5,77 8,65 0,96 8,651,92 0,000,96 0,000,960,961,92 0,96 0,96 100

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semitones (M23). In the musical mode infants’ vocalizations cover extensions between 0 and 12 semitones (isolated sounds and P8) while the experimenter’s vocal stimuli cover extensions between 0 and 13 semitones (isolated sounds and m9).

In the linguistic mode, infant vocalizations were situated predominantly between 0 and 7 semi-tones (isolated sounds –P5). Effectively, 91% of infant vocalizations occurred within this range; 3 semitones (m3), isolated sounds and 2 semitones (M2) were the most frequent extensions of infant vocalizations. When analyzing the frequency of infant vocalizations in relationship with each lin-guistic stimulus, we observe a sparse distribution. The highest frequency of infants’ vocalizations (4) occurred for the situation in which the stimulus was 7 semitones (P5) and 4 semitones (M3). In these cases, infants’ vocalizations were isolated sounds or had 3 semitones (m3) of vocal extension. The prevalent extensions of the experimenter’s vocal stimuli were situated between 3 and 17 semi-tones (M2 – P11), which represent 78% of the experimenters’ vocal stimuli; 4 semitones (M3) was the most frequent extension of the experimenter’s vocal stimuli.

In the musical mode 88% of infant vocal production were vocalizations with the extension of 0, 1, 2, 3 and 4 semitones (isolated sounds, m2, M2, m3 and M3, respectively). Isolated sounds present 51% of the overall distribution with three peaks in the distribution occurring for the cases in which the vocal stimuli were 10, 7 and 4 semitones (m7, P5 and M3). The prevalent vocal exten-sions of the stimuli were 2, 3, 4, 5, 7, 10 and 12 semitones (M2, m3, M3, P4, P5, m7, P8, respec-tively), which represents 96% of the experimenters’ vocal stimuli; 7 (P5) and 12 (P8) semitones were the most frequent experimenter vocal extensions.

Infants’ vocalizations in response to musical stimuli were also subjected to an aural analysis in order to describe their structure, as reported in Table 4. For this parameter it was observed that 98% of the vocalizations were categorized as related to the musical stimulus and 2% were categorized as unrelated to it and so the unrelated were excluded in order to make comparisons within the musi-cal categories. So, the percentages reported in Table 4 refer just to vocalizations that are related to the musical stimuli.

Table 3. Frequency (%) of infants’ vocalizations and musical stimulus according vocal extension in the musical context

Vocal extension (semitones) in musical context

Stimuli (Experimenter)

Infant productions

0 1 2 3 4 5 6 7 9 13 Totals %

0 1 0 0 0 0 0 0 0 0 0 1 0.68 2 4 0 0 1 1 1 0 0 0 0 7 4.79 3 6 2 1 1 0 0 0 2 0 0 12 8.22 4 12 4 5 0 2 0 0 2 0 0 25 17.12 5 8 0 4 2 1 1 0 0 0 0 16 10.96 7 12 2 2 0 4 1 0 0 0 0 21 14.38 8 9 0 0 2 2 0 0 0 0 0 13 8.90 9 0 1 0 0 1 0 1 0 0 0 3 2.0510 14 0 1 3 1 1 0 0 0 1 21 14.3811 2 0 0 0 0 0 0 0 0 0 2 1.3712 7 5 3 0 3 2 0 3 2 0 25 17.12Totals 75 14 16 9 15 6 1 7 2 1 146 100.00% 51.37 9.59 10.96 6.16 10.27 4.11 0.68 4.79 1.37 0.68 100.00 68.49


Most of the vocalizations are categorized as isolated sounds, described in terms of scalar steps with reference to the musical stimuli. It can be seen that the highest percentage of the isolated sounds corresponds to the first step (tonic) of the musical stimulus. The third step (mediant) was also prominent in infant vocalizations. Melodic intervals and melodic contours were the next categories found in infant vocalizations.

An analysis of the content of the melodic intervals reveals a large percentage (94%) of descend-ing motion, 38% of which descended to the first step of the scale (tonic). Ascending intervals accounted for only 6%.

It was also observed that the majority of infant vocalization occurred as a result of particular vocal stimuli, specifically melodic patterns with an extension of 4 semitones (‘Merry Go Round’: the fourth and the eighth bars) and 7 semitones (‘Merry Go Round’: the first and second bars, of the third and fourth bars and of the two first bars of phrase B); and phrases with an extension of 10 semitones (‘Amy’: phrase B) and 12 semitones (‘Merry Go Round’: the whole phrase of A or each of its halves; ‘The Swan’: the last four bars). Thus, most infant vocalizations in response to music occurred at specific points and in response to specific sections of each song.

Discussion

Results showed that infants’ vocalizations produced after linguistic stimuli were different in terms of duration and extension from those produced after musical stimuli.

Infants’ vocalization seems to be of longer duration in the linguistic mode than in the musical one. In fact, the shortest vocalization produced in response to linguistic stimuli was longer than the longest vocalization produced in response to musical stimuli. Our findings also indicate that there

Table 4. Number of infant vocalizations by category in musical context

Type Frequency Relative % Total %

Isolated sounds 44 42.3

Tonal steps I 28 63.6 II 3 6.8 III 9 20.5 IV 0 0.0 V 4 9.1 VI 0 0.0 VII 0 0.0

Melodic intervals 26 25.0 Ascending movement 6.1 Descending movements

towards the tonic37.6

Other descending movements

56.3

Melodic contour 24 23.1Melodic exploration 10 9.6

100.0

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was more variability in the duration of infants’ vocalizations that were produced in response to linguistic stimuli than those produced in response to musical stimuli.

The longer duration of infant vocalizations in response to language may be the result of infants’ greater daily exposure to linguistic stimuli. Indeed, as shown by Oller (1980), Stark (1981) and, more recently, through the studies conducted by Boysson-Bardies (1999) and M. Papousek (1996), infants of this age group already produce clearer elocutions and a greater variety of syllables. Also, the existence of greater variability in the duration of infants’ vocalizations produced in a linguistic context may reflect each infant’s ongoing process of speech acquisition.

Some of them already may be in a more advanced stage (as in the use of more than one word), while others may be in more preliminary stages of language babbling. This suggests the hypothesis that in the acquisition of singing, infants at this age are still at a preliminary stage in which, unlike their linguistic vocalizations, they seem to be concentrated within a smaller durational scope. It might also be that the novelty of musical stimuli captivates the listening attention of the infant, who then vocalizes at specific moments of the musical stimuli. Or it may be that these differences reflect processing differences between singing acquisition and language acquisition. In any case, the most important thing to retain is that the duration of infant vocalizations differs according to the different natures of the stimuli.

The results of F0 analysis also indicate that infant vocal production is different between modes. In comparing the infants’ F0 values, it is clear that although minimum values are similar, maxi-mum values are different in both modes, the maximum F0 value being quite lower in the musical mode than in the linguistic one. So, the analysis of amplitude of F0 values demonstrated that in the musical mode infants have restricted their vocal range approaching the extension of the vocal stimuli. This was shown also by the analysis of the extension of the most prevalent infants’ vocali-zations. In fact, even though the most prevalent infants’ vocalizations presented shorter extensions than the most prevalent experimenter’s vocal stimuli both in the linguistic mode and in the musical mode, the results show that in the case of the musical mode infants squeezed the extension of their vocalizations in a similar proportion to that of the experimenter.

It was found that infants’ vocalizations in response to musical stimuli were more concentrated and restricted in terms of extension. By contrast, in the linguistic mode infants adapted themselves to the stimuli and explored a much wider range of extension in their vocalizations.

Results also revealed that infant vocal responses to musical stimuli occurred at specific moments of the song, without interrupting its flow. This suggests that infants aged 9–11 months have knowl-edge about the hierarchical organization of music. That is, they seem already to have a perception of the “musical whole” (or at least some notion of “musical segments”), which they punctuate by vocalizing in its boundaries. We wonder if this might be related to Krumhansl’s & Jusczyk’s (1990) observation that infants 4 to 6 months old were capable, in a perceptive behavior, of detecting and demonstrating preferences for “good musical phrasing.”

That is, in this study there is evidence of infants’ perception of musical boundaries, which is supported by their propensity to vocalize at appropriate moments.

An alternative explanation could emphasize the important role of the adult in stressing musical hierarchy, as proposed by Longhi through the concept of “songese” (Longhi, 2009). In such a man-ner, the adult singer establishes regularities that can help infants to segment the flow of the song. In our study, it may be that infants’ vocalizations in the musical mode were elicited by that kind of singing. That is, an emphasis on some specific units in the musical stimuli might have elicited the infants’ vocalizations at certain moments of the song. However, this would need to be confirmed in future studies.

Related to these findings is the evident importance that infants give to the tonal hierarchy of the song. When exposed to the songs infants limited their vocalizations to short patterns (melodic


intervals and contours) and mainly to isolated sounds that repeated important degrees of the scale (with emphasis on the tonic and on the mediant). These results seem to reveal purposeful reactions to musical stimuli. In fact, infants’ vocal explorations do not seem to be the result of chance; certain scalar steps were clearly favored.

Furthermore and in agreement with Fox (1983) and Moog (1976), there were many more occur-rences of descending melodic intervals than ascending ones, many of them towards the tonic of the song. Probably due to the relational and non-referential nature of musical perception (Schellenberg & Trehub, 1996a), infants tend to focus primarily on the tonal structure inherent in the songs, responding contextually. Since in the linguistic mode there is no deliberate concern for tonal organ-ization, infants probably tend to interact according to phonological features prominent in the poems that were used.

Our findings seem to indicate that infants vocalize differently in response to linguistic and musical stimuli and that singing elicits a specific infant vocal behavior. The demonstration of the occurrence of specific vocal responses to singing might reveal that very early in human develop-ment there emerges an important capacity to respond discriminately to music.

This finding corroborates the existence of an early predisposition to act musically, reiterating the importance of an early musical enculturation, as many authors have argued. Several studies have investigated this predisposition through perception tasks (Krumhansl & Jusczyk, 1990; Schellenberg & Trehub, 1994; Trehub et al., 1984; Trehub & Thorpe, 1989; Trehub et al., 1985, 1987; Trehub et al., 1999). The results obtained in this study might help to complement knowledge of the process of singing acquisition in infancy.

This might have important implications for music education because if there is a difference between the speaking voice and the singing voice of every child, regardless of chronological age – as stated by Gordon (1998) – music educators should be concerned about the acquisition singing skills very early in childhood. So, future investigations should study the vocalizations of infants that have been musically encouraged from birth and that were exposed to singing during mother’s pregnancy. In parallel, we should study how infants would vocalize in response to different musical stimuli, aiming to clarify the role of musical enculturation in acquisition of singing skills and in musical learning.

Nevertheless, before we use the expression “musical babbling” we should carry out longitudinal studies to compare how infants vocalize from birth in response to musical and linguistic stimuli under varying conditions. Such research could enhance our knowledge of the acquisition both of language and of musical skills and the pathways between the two.

Acknowledgement

This research was supported by the Portuguese Foundation for Science and Technology (Fundação para a Ciência e Tecnologia) (Musical Development in Infancy and Early Childhood Research Project-PTDC / EAT / 68361/2006). We thank Professors Albert Bregman and Orlindo Gouveia Pereira for their advice.

References

Adachi, M. (1994). The role of the adult in the child’s early musical socialization: A Vygotskian perspective. The Quarterly: Journal of Music Teaching & Learning, 5(3), 26–35.

Adachi, M. (2006, August). Japanese home environments and infants’ spontaneous responses to music: An initial report. Paper presented at the 9th ICMPC, Bologna, Italy.

Adachi, M., Nakata, T., & Kotani, Y. (2002). Infants encountering music: An exploration of musical affordances. In C. Stevens, D. Burnham, G. McPherson, E. Schubert, & J. Renwick (Eds.), Proceedings

Reigado et al. 251

of the 7th International Conference on Music Perception and Cognition [CD-ROM] (pp. 454–456). Adelaide, Australia: Causal Productions.

Boersma, P., & Weenink, D. (2006). Praat: Doing phonetics by computer (Version 4.4.04) [Computer software]. Retrieved February 2006, from http://www.praat.org/

Boysson-Bardies, B. (1999). How language comes to children. Cambridge: The MIT Press.Cooper, R., & Aslin, R. (1990). Preference for infant-directed speech in the first month after birth. Child

Development, 61, 1584–1595.Dowling, W. (1999). The development of music perception and cognition. In D. Deutsch (Ed.), The Psychology

of Music (pp. 603–625). San Diego: Academic Press.Fernald, A. (1989). Intonation and communicative intent in mothers’ speech to infants: Is the melody the

message? Child Development, 60, 1497–1510.Fernald, A. (1991). Prosody in speech to children: Prelinguistic and linguistic functions. Annals of Child

Development, 8, 43–80.Fernald, A., & Simon, T. (1984). Expanded intonation contours in mother’s speech to newborns. Developmental

Psychology, 20, 104–113.Fox, D. (1983). The pitch range and contour of infant vocalizations. (Doctoral dissertation, The Ohio State

University, 1982). Dissertation Abstracts International, 43, 2588A.Gerry, D., Faux, A., & Trainor, L. (2010). Effects of Kindermusik training on infants’ rhythmic enculturation.

Developmental Science, 13(3), 1–7.Gordon, E. (1998). A music learning theory for newborn and young children. Chicago: GIA Publications.Gordon, E. (2000). Teoria de aprendizagem musical: Competências, conteúdos e padrões. Lisboa: Fundação

Calouste Gulbenkian.Gordon, E., Bolton, B., Hicks, W., & Taggart, C. (1993). The early childhood music curriculum: Experimental

songs and chants without words: Book one. Chicago, IL: GIA Publications.Hairer, M. (2005). Amadeus II (Version 3.8.4.) [Computer software]. Kenilworth: HairerSoft.Hannon, E., & Trainor, L. (2007). Music acquisition: Effects of enculturation and formal training on devel-

opment. TRENDS in Cognitive Sciences 11(11), 466–472.Hargreaves, D. (2001). The developmental psychology of music. Cambridge: Cambridge University Press.Hefer, M., Weintraub, Z., & Cohen, V. (2009). Musical cognition at birth: A qualitative study. Early Child

Development and Care, 179(6), 769–783.Honing, H., Ladinig, O., Háden, G., & Winkler, I. (2009). Do newborn infants sense the beat? In J. Louhivuori,

T. Eerola, S. Saarikallio, T. Himberg, & P-S. Eerola (Eds.), Proceedings of the 7th Triennial Conference of European Society for the Cognitive Sciences of Music – ESCOM 2009. Jyväskylä, Finland, 200–201.

Ilari, B. (2002). Music perception and cognition in the first year of life. Early Child Development and Care, 172, 311–322.

Ilari, B., & Sundara, M. (2009). Musical preferences in early life: Infants’ responses to accompanied and unaccompanied singing. Journal of Research in Music Education, 56(4), 357–369.

Ingram, D. (1989). First language acquisition: Method, description and explanation. New York: Cambridge University Press.

Jusczyk, P., Friederici, A., Wessels, J., Svenkerud, V., & Jusczyk, A. (1993). Infants’ sensitivity to the sound patterns of native language words. Journal of Memory and Language, 32, 402–420.

Kida, I., & Adachi, M. (2008). The role of musical environment at home in the infant’s development (Part 2): Exploring effects of early musical experiences on the infant’s physical and motor development during the first 2 years. In K. Miyazaki, Y. Hiraga, M. Adachi, Y. Nakajima, & M. Tsuzaki (Eds.), Proceedings of the 10th International Conference on Music Perception and Cognition. Sapporo: Hokkaido University, 722–728.

Kotilahti, K., Nissilä, I., Näsi, T., Lipiäinen, L., Noponen, T., & Meriläinen, P., et al. (2010). Hemodynamic responses to speech and music in newborn infants. Human Brain Mapping, 31(4), 595–603.

Krumhansl, C., & Jusczyk, P. (1990). Infants’ perception of phrase structure in music. Psychological Science 1(1), 70–73.


Kuhl, P. (1991). Perception, cognition, and the ontogenetic and phylogenetic emergence of human speech. In S. Brauth, W. Hall, & R. Dooling (Eds.), Plasticity of development (pp. 73–106). Cambridge, MA: MIT Press.

Letria, J. (1999). Versos de fazer ó-ó. Lisboa: Terramar.Longhi, E. (2009). ‘Songese’: maternal structuring of musical interaction with infants. Psychology of Music,

37, 195–213.Mehler, J., Jusczyk, P., Lambertz, G., Halsted, G., Bertoncini, J., & Amiel-Tison, C. (1988). A precursor of

language acquisition in young infants. Cognition, 29, 143–178.Moog, H. (1976). The development of musical experience in children of pre-school age. Psychology of Music,

4, 38–45.Morgan, J., & Saffran, J. (1995). Emerging integration of sequential and suprasegmental information in

preverbal speech segmentation. Child Development, 66, 911–936.Nazzi, T., Bertoncini, J., & Mehler, J. (1998). Language discrimination by newborns: Towards an understand-

ing of the role of the rhythm. Journal of Experimental Psychology: Human Perception and Performance, 24, 756–766.

Oller, D. K. (1980). The emergence of the sounds of speech in infancy. In G. YeniKomshian, J. Kavanagh, & C. Ferguson (Eds.), Child phonology, Volume 1. Production (pp. 93–112). New York: Academic Press.

Papousek, H. (1996). Musicality in infancy research: Biological and cultural origins of early musicality. In I. Deliége & J. Sloboda (Eds.), Musical beginnings: Origins and development of musical competence (pp. 37–51). Oxford: University Press.

Papousek, M. (1996). Intuitive parenting. In I. Deliège & J. Sloboda (Eds.), Musical beginnings: Origins and development of musical competence (pp. 88–112). Oxford: University Press.

Pegg, J., Werker, J., & McLeod, P. (1992). Preference for infant-directed over adult-directed speech: Evidence from 7-week old infants. Infant Behavior and Development, 15, 325–345.

Rocha, A., Reigado, J., & Rodrigues, H. (2008). As vocalizações de bebés de 9 a 11 meses face à música e à linguagem: análise efectuada por juízes especializados [The vocalizations of infants of 9 to 11 months old towards music and language: Analysis by expert judges]. In P. Martins (Ed.), Infâncias Possíveis, Mundos Reais, Resumos do I Congresso Internacional em Estudos da Criança [CD-ROM] (pp. 97–98). Braga: Universidade do Minho.

Rocha, A., Reigado, J., Silva, D., & Rodrigues, H. (2009). Existe uma vocalização do bebé específica para a música? Estudos exploratórios de padrões acústicos de produções vocais de bebés entre os 9 e os 11 meses [Do babies vocalise specifically to music? An exploratory study into the acoustic patterns of the vocal productions of babies between 9 and 11 months] [CD-ROM]. In H. Marinho, S. Sardo, & J. S. Correia (Eds), Proceedings of the conference on Performance Studies/Actas dos Encontros de Investigação em Performance [CD-ROM]. Aveiro: Universidade de Aveiro.

Rodrigues, H. (2005). A Festa da Música na iniciação à vida: da musicalidade das primeiras interacções humanas às canções de embalar [The festival of music at the begining of life: From the musicality of first human interactions to human lullabies]. Revista da Faculdade de Ciências Sociais e Humanas, 17, 61–80.

Rodrigues, H., Rodrigues, P., & Nunes, P. (2003). Bebébabá: Da musicalidade dos afectos à música com bebés [BebéBabá – travelling from affection’s musicality to music for babies]. Porto: Campo das Letras Editores.

Schellenberg, E. G., & Trehub, S. E. (1994). Frequency ratios and the perception of tone patterns. Psychonomic Bulletin & Review, 1, 191–201.

Schellenberg, E. G., & Trehub, S. E. (1996a). Children’s discrimination of melodic intervals. Developmental Psychology, 32, 1039–1050.

Schellenberg, E. G., & Trehub, S. E. (1996b). Natural musical intervals: Evidence from infant listeners. Psychological Science, 7, 272–277.

Stark, R (Ed.). (1981). Language behavior in infancy and early childhood. New York: Elsevier North Holland.Tafuri, J., & Villa, D. (2002). Musical elements in the vocalizations of infants aged 2–8 months. British

Journal of Music Education, 19(1), 73–88.Trainor, L. (1996). Infant preferences for infant-directed versus noninfant-directed playsongs and lullabies.

Infant Behavior and Development, 19, 83–92.

Reigado et al. 253

Trainor, L., & Trehub, S. (1993). Musical context effects in infants and adults: Key distance. Journal of Experimental Psychology: Human Perception and Performance, 19(3), 615–626.

Trainor, L. J., & Trehub, S. E. (1994). Key membership and implied harmony in Western tonal music: Developmental perspectives. Perception & Psychophysics, 56, 125–132.

Trehub, S. E. (2003). Musical predispositions in infancy: an update. In I. Peretz & R. Zatorre (Eds.), The cognitive neuroscience of music (pp. 3–20). Oxford: Oxford University Press.

Trehub, S. E., Bull, D., & Thorpe, L. A. (1984). Infants’ perception of melodies: The role of melodic contour. Child Development, 55, 821–830.

Trehub, S. E., Schellenberg, E. G. & Kamenetsky, S. B. (1999). Infants’ and adults’ perception of scale structure. Journal of Experimental Psychology: Human Perception and Performance, 25, 965–975.

Trehub, S. E., & Thorpe, L. (1989). Infants’ perception of rhythm. Categorization of auditory sequences by temporal structure. Canadian Journal of Psychology, 43, 217–229.

Trehub, S. E., Thorpe, L., & Morrongiello, B. (1985). Infants’ perception of melodies: Changes in a single tone. Infant Behavior and Development, 8, 213–223.

Trehub, S. E., Thorpe, L., & Morrongiello, B. (1987). Organizational processes in infants’ perception of auditory patterns. Child Development, 58, 741–749.

Van Puyvelde, M., Vanfleteren, P., Loots, G., Deschuyffeleer, S., Vinck, B., & Jacquet, W., et al. (2010). Tonal synchrony in mother–infant interaction based on harmonic and pentatonic series. Infant Behavior and Development, 33(4), 387–400.

Welch, G. (1994). The assessment of singing. Psychology of Music, 22, 3–19.

Author biographies

João Pedro Reigado is completing his PhD in Musicology – Psychology and Music Education, at Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa. He works at the Laboratory for Music and Communication in Infancy of CESEM as a member of the Musical Development in Infancy and Early Childhood project team supported by the Portuguese Science and Technology Foundation (PTDC/EAT/68361/2006). He graduated in Music Education and teaches music from kindergarten through high school. He has attended courses on piano, voice, choral conducting, music pedagogy and music therapy. He is a co-founding member and musical director of the Staccato Ensemble with whom he participated in the creation, interpretation and co-production of the medieval-inspired musical Hoy Comamos. He has presented professional training activities for teachers, with a focus on music psychology, music development and cur-ricula, in Portugal and Switzerland. As a researcher he has interests in the field of early childhood music learning in general, particularly with regard to infant vocalizations in music and linguistic contexts. In 2009 he published his master’s thesis under the name of ‘Análise acústica das vocalizações de bebés de 9 a 11 meses face a estímulos musicais e linguísticos’ [Acoustic analysis of infants’ vocalizations of 9 to 11 months in response to musical and linguistic stimuli].

António Rocha is a PhD student in Musicology, specializing in psychology and music education at Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa. He is a member of CESEM’s Laboratory for Music and Communication in Infancy research team and a music teacher in a public school at Costa de Caparica, Almada (AVE da Costa de Caparica – M. E.). He began his professional career in 1990, having taught at various levels of education, from music lessons in kindergartens, to music pedagogy in undergraduate classes. Since 1999 and based on Music Learning Theory by Edwin E. Gordon, he has been involved in Music for Babies projects in many music schools. He is part of the teachers’ team for the Early Childhood Music Guidance project at the Musicentro/Salesianos School of Lisbon, coordinated by Victor Gaspar (singer and choir direc-tor). He is also involved in theater and musical theater, as an interpreter, composer, music consultant, sound designer and musical director. He has worked with nationally and internationally known stage directors such as Jorge Listopad, Rogério de Carvalho, Sylvio Zilber, Jorge Fernando Lopes and Sílvina Pereira.

Helena Rodrigues is Professor of Psychology of Music and Music Pedagogy at Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa and the scientific coordinator of the Laboratory for Music and


Communication in Infancy of CESEM, a research unit in that institution. She is one of the founders of Companhia de Música Teatral (http://www.musicateatral.com), a group specializes in creating artistic and educative projects that have music at the root of interdisciplinary practice and has pioneered educational, interdisciplinary and music community arts projects in Portugal. She has disseminated Edwin Gordon’s Music Learning Theory in Europe since 1994, and is an expert in psychology of music/musical development in early childhood and infancy. She holds a PhD in Psychology from the University of Coimbra and a Piano Diploma from the Music Conservatoire of Oporto. She has attended courses in chamber music, music pedagogy, music psychology, therapies, voice and drama and she sings regularly with the Gulbenkian Choir. She presents workshops and lectures in Portugal, Spain, Lithuania, Austria, Germany, Norway, the USA, Belgium, Canada, the UK and Poland.

Source: Gordon, Bolton, Hicks, & Taggart (1993).

Appendix A: Songs used in the experimental sessions

Reigado et al. 255

Appendix B: Poems used in the experimental sessions

Uma pestana, outra pestana para tecer essa cortinacom que o sono vai tapar o olhar desta meninaque, enrolada no meu colo, parece tão pequenina.This is your eyelash, that is your eyelash for weaving together a curtainto cover up my little girl’s eyes, my little girl now fallingasleep, now falling fast asleep, so snugly fast asleep in my lapUm cavalo, outro cavalo sobre as nuvens a correr,para te trazerem o sono que te faz adormecer,meu menino, pequenino, que tudo queres saber.This little horse, that little horse, running high up above the cloudsRocking you fast asleep, asleep on your horse, to sleep, to sleep,My little boy, my little one, who wants to know everythingO ursinho de peluche sabe todos os segredosque a Marta às vezes conta aos seus amigos brinquedos,sentinelas que afugentam os papões e outros medos.Your teddy bear has heard, he knows ev’ry little whispered secretthat your Marta has told to all her friends, the little toys that you sharewho protect you from the bogeyman and keep away all your bad dreams

Source: Letria (1999).

Abstracts

Vocalisation chez les enfants (9–11 mois d’âge) en réponse aux stimuli musicaux et linguistiques

La présente étude analyse les réponses vocales enfantine afin de déterminer si les enfants exposés aux stimuli linguistiques et musicaux exhibent types différentes de vocalisation en réponse à ces deux différentes sortes de stimulus. 21 enfants, de l’âge du 9 à 11 mois, ont été observées quatre fois par semaine pendant un mois. Chaque session a été composée de deux présentations: une musicale, dans laquelle le chercheur chantait, et l’autre linguistique, où le chercheur récitait des poèmes. Les vocalisations des enfants ont été enregistrées et soumis à l’analyse auditive et acous-tique. Les résultats ont montré que les vocalisations des enfants en réponse aux deux sortes de stimulus portent différentes caracteristiques de durée et d’extension vocale. Vocalisations chez les enfants en réponse aux stimuli musicaux consistent principalement de sons isolés, avec une haute percentage des premier et troisième degrés de l’échelle du stimulus musical, ainsi que la prédomi-nance des intervalles mélodiques et des contours soulignant les plus importantes dégres du stimu-lus. Des intervales descendants ont été aussi une caracteristique de la production vocale de l’enfant en repónse aux stimuli musicaux.

Vokalisationen von Säuglingen (Alter 9–11 Monate) als Reaktion auf musikalische und linguistische Stimuli

Diese Studie analysiert vokale Erwiderungen von Säuglingen, mit dem Ziel festzustellen, ob Säuglinge die sowohl linguistischen als auch musikalischen Stimuli ausgesetzt sind verschiedene Weisen der vokalen Reaktion auf die jeweiligen Arten der Stimuli zeigen. Einundzwanzig Säuglinge


im Alter von neun bis elf Monaten wurden über einen Zeitraum von einem Monat in insgesamt vier wöchentlichen Sitzungen beobachtet. Jede Sitzung bestand aus zwei Präsentationen: Einer musika-lischen, in welcher der Experimentator sang und einer lingusitschen, in welcher dieser Gedichte erzählte. Die Vokalisationen der Säuglinge wurden aufgenommen und einer oralen und akustischen Analyse unterzogen. Die Ergebnisse zeigten, dass die Vokalisationen der Säuglinge in Reaktion auf musikalische Stimuli hautsächlich aus isolierten Klängen bestanden. Zu beobachten war sow-ohl eine hohe Zahl an ersten und dritten Stufen der dem musikalischen Stimulus zu Grunde lieg-enden Tonleiter, wie auch eine Dominanz von melodischen Intervallen und Konturen, welche die wichtigen Tonleiterschritte des musikalischen Stimulus umrissen. Auch absteigende Intervalle waren ein Charakteristikum des vokalen Ausdrucks der Säuglinge in Reaktion auf musikalische Stimuli.

Vocalizaciones Infantiles (de 9 a 11 meses) en respuesta a estímulos lingüísticos y musicales

Este estudio analiza las respuestas vocales infantiles a fin de determinar si los niños expuestos a estímulos musicales y lingüísticos muestran diferentes tipos de vocalizaciones en respuesta a esos diferentes tipos de estimulación. Se observaron a 21 bebés de entre 9 y 11 meses a razón de cuatro sesiones semanales durante un mes. Cada sesión constó de dos presentaciones: musical, en la que el experimentador cantó; y lingüística, en la que narró poemas. La vocalización de los niños se grabó y remitió para su posterior análisis acústico y fonético. Los resultados mostraron que las vocalizaciones de los bebés en respuesta a ambas presentaciones tenían diferentes características de duración y extensión vocal. Las vocalizaciones en respuesta a los estímulos musicales básica-mente consistieron en sonidos aislados, con un alto porcentaje de primeros y terceros grados de la escala de estímulos musicales, así como un predominio de intervalos y contornos melódicos que esbozan importantes avances en la escala de estimulación. Los intervalos descendentes son igual-mente característicos de la producción vocal infantil en respuesta a los estímulos musicales.

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