Infant Behavior & Development 33 (2010) 96–100
Contents lists available at ScienceDirect
Infant Behavior and Development
Does the message matter? The effect of song type on infants’
pitch preferences for lullabies and playsongs
Christine D. Tsang a,∗ , Nicole J. Conrad b
a
b
Department of Psychology, Huron University College at the University of Western Ontario, 1349 Western Road, London, Ontario, Canada N6G 1H3
Department of Psychology, Saint Mary’s University, Halifax, Nova Scotia, Canada
a r t i c l e
i n f o
Article history:
Received 3 July 2009
Received in revised form
23 November 2009
Accepted 26 November 2009
Keywords:
Infant
Pitch perception
Music perception
a b s t r a c t
Preverbal infants are attuned to the different emotional messages contained in playsongs
and lullabies. However, it is unclear which performance properties of singing underlie
infants’ perception of the communicative intent of infant-directed singing. Volkova, Trehub,
and Schellenberg (2006) recently demonstrated that 6- and 7-month-old infants preferred
low-pitched to high-pitched renditions of lullabies, suggesting that pitch may be one performance characteristic that conveys the communicative intent in infant-directed singing.
In the current study, we evaluated 6- and 7-month-old infants’ natural preferences for unfamiliar, expressive lullabies and playsongs as a function of pitch using a head-turn preference
procedure. Infants preferred low-pitched over high-pitched versions of lullabies and highpitched over low-pitched versions of playsongs. Results suggest that the overall pitch of a
song is communicative to infants and that the affective nature of music can have an effect
on infants’ pitch preferences. That is, infants’ preferences for pitch are context-dependent.
© 2009 Elsevier Inc. All rights reserved.
It is often said about infant-directed speech that the message is in the melody (Fernald, 1989), indicating that the manner
in which caregivers speak to their infants is more informative to infant listeners than the specific words in the utterance.
This suggests that performance features of infant-directed speech (such as pitch level, rhythmicity and tone of voice) are
central to infant-caregiver communication. Indeed, the sing-song manner in which caregivers talk to their infants is often
termed “musical speech” (e.g., Fernald, 1991). Thus, many of the performance features, such as pitch level, of infant-directed
speech can also be discussed in the context of infant-directed singing. Certainly, many studies have shown the importance
of the role of pitch level and tone of voice on infant preferences for both infant-directed speech and singing (e.g. Fernald,
1991; Trainor, 1996; Trainor & Zacharias, 1998).
All over the world, in all cultures, caregivers sing to their infants (Brakeley, 1950; Trehub & Schellenberg, 1995). Infants
are attracted to maternal singing more than to maternal speech (Nakata & Trehub, 2004), and maternal singing is related
to the modulation of infant arousal. Thus, a primary function of infant-directed singing seems to be to regulate arousal or
communicate emotional states with preverbal infants (Trainor, 1996; Trehub & Schellenberg, 1995; Trehub, Trainor, & Unyk,
1993). Indeed, music is generally used to express emotions, or arouse emotions in others (see Juslin & Sloboda, 2001). Adult
listeners are able to attribute basic emotions (e.g., happiness, sadness, fear, anger) to musical compositions (e.g., Cupchick,
Rickert, & Mendelson, 1982), and even 3-year-olds are able to associate emotions with specific musical excerpts (e.g., Trainor
& Trehub, 1992). Musicologists have long believed that musical meaning is contained in the emotions a musical piece evokes
(e.g., Meyer, 1956).
∗ Corresponding author. Tel.: +1 519 438 7224; fax: +1 519 438 3938.
E-mail address: [email protected] (C.D. Tsang).
0163-6383/$ – see front matter © 2009 Elsevier Inc. All rights reserved.
doi:10.1016/j.infbeh.2009.11.006
C.D. Tsang, N.J. Conrad / Infant Behavior & Development 33 (2010) 96–100
97
Different types of infant-directed songs are used by caregivers to convey different affective messages. Lullabies are
used to sooth and calm an infant, whereas playsongs are used to stimulate (Trehub & Trainor, 1998). The differences
in the communicative nature of lullabies and playsongs are also reflected in the structural and performance features
of lullabies and playsongs. In terms of performance, lullabies are generally sung by caregivers in a lower pitch and a
slower tempo than playsongs, while playsongs are generally high in pitch and highly rhythmic. The differences in performance features are clearly discriminable to adult listeners and likely serve as a basis for categorization of song types.
Trainor (1996) found that adult raters were consistent in their classifications of maternal singing as either playsongs
or lullabies, and rated lullabies as rendered in a more loving manner. Rock, Trainor, and Addison (1999) found similar results, in that adult listeners were able to correctly classify exemplars of maternal singing as either playsongs or
lullabies.
Not only are the performance features of lullabies and playsongs different and perceptually discriminable, but
they also elicit different behavioural responses from infants. Rock et al. (1999) found that 6-month-old infants
directed their attention outward and looked more often at their caregivers while listening to playsongs, whereas their
attention was more directed inward while listening to lullabies. Physiological arousal may also be affected by different types of infant-directed singing. Shenfield, Trehub, and Makata (2003) measured cortisol levels in 6-month-old
infants and found that playful maternal singing promoted arousal levels optimal for attention. The authors speculated that more soothing forms of maternal singing, such as lullabies, may decrease arousal levels, although this
was not directly tested. Together, these results suggest that infants are attuned to the communicative nature of
singing.
However, it is unclear which performance properties underlie infants’ perception of the communicative intent of infantdirected songs. In general, both infant-directed speech and singing are characterized by higher pitch levels (infant-directed
speech is also characterized by broader pitch ranges), slower tempos (infant-directed speech has also been found to be
more rhythmic), and are rendered in a more loving manner than adult-directed speech and singing (Fernald, 1991; Trainor,
1996; Trainor, Clark, Huntley, & Adams, 1997; Trehub & Trainor, 1998; Trehub et al., 1993). Infants show a preference for
infant-directed singing over infant-absent singing (Trainor, 1996), a preference that is present even in newborns (Masataka,
1999). This preference for infant-directed stimuli is thought to be partially due to infants’ preferences for higher-pitched
voices (e.g., Fernald, 1991; Trehub & Trainor, 1990). However, Trehub and Trainor (1998) note that an elevated pitch level
may be more common in playsongs than lullabies, suggesting that infants’ preferences for different genres of infant-directed
singing need to be more closely examined.
Trainor and Zacharias (1998) examined pitch preferences in infant-directed singing and found that 6-month-old
infants preferred to listen to high-pitched over low-pitched versions of the same song. This finding was consistent across
both lullabies and playsongs, further supporting the notion that infants have a generalized preference for high-pitched
sounds, as similar results have been found with speech (Fernald, 1991). However, Volkova, Trehub, and Schellenberg
(2006) argued that the results of Trainor and Zacharias may be difficult to generalize, as the singing was performed
in an non-infant-directed manner, songs were used that were likely familiar to the infants, and the pitch levels were
often outside the range of pitch caregivers typically use when singing. In their own study using foreign lullabies,
Volkova et al. (2006) found that 6- and 7-month-old infants preferred to listen to low-pitched lullabies over highpitched lullabies, a finding that is inconsistent with Trainor and Zacharias (1998). Conversely, these results are consistent
with the idea that the nature of the music can affect infants’ preferences (Saffran, Reeck, Neibuhr, & Wilson, 2005)
and that infants are sensitive to the underlying affective message contained within the songs. However, to further
support this conclusion, infant preferences for pitch within other genres of music, such as playsongs, must be examined.
Volkova et al. argued that a novelty preference may also explain the high pitch preference found by Trainor and Zacharias
(1998), in that the high-pitch versions of the songs used by Trainor and Zacharias were out of the range that caregivers
typically use when singing to their infants and were therefore highly novel to the infants.
It is also possible that the low-pitch preferences shown by infants in Volkova et al. (2006) reflected a novelty preference.
Caregivers show a tendency to sing to infants during play and most often sing playsongs to infants (Trehub et al., 1997). This
tendency also results in infants being exposed to more high-pitched singing, so infants in Volkova et al.’s study may have
preferred the low-pitched versions of the lullabies because they are accustomed to hearing high-pitched singing and may
have found the low pitch versions of the lullabies particularly novel and interesting. In order to determine whether listening
experiences with specific song types affect infants’ preferences, the frequency of singing and the nature or context of singing
by caregivers to their infants should be examined.
Together, these studies suggest that pitch may be an informative performance-based aspect of infant-directed singing. To
that end, in the current study we have focused on pitch as that performance feature of singing to which infants are sensitive
and from which infants derive the affective message. Our interest was to determine whether infant preferences are context
dependent. We examined infants’ natural preferences for unfamiliar lullabies and playsongs as a function of pitch using a
head-turn preference procedure. In addition, caregivers were asked what types of songs they typically sung to their infant
to further examine the role of singing exposure on infant novelty preferences. It was hypothesized that elevated pitch levels
may enhance the expressiveness of playsongs, but not lullabies. Furthermore, if preferences are based on expressiveness, as
they appear to be for speech (Singh, Morgan, & Best, 2002), we would expect infants to show a preference for high-pitched
playsongs and low-pitched lullabies.
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1. Methods
1.1. Participants
Sixteen 6–7-month-old infants (10 males, 6 females) participated in this study (mean age = 6.8 months, range = 5.9–7.4
months). The infants who participated were healthy at the time of testing and had no history of ear infections or a family
history of hearing impairment. Four additional infants were tested but excluded, two infants due to technical problems
during testing and two infants who fell outside of the 6–7-month-old age range because of scheduling conflicts.
1.2. Apparatus
Infants were tested individually in a quiet laboratory room. Each infant was seated facing forward on the caregiver’s lap,
with the experimenter sitting directly across from the infant and caregiver. The experimenter sat directly opposite the infant
at a distance of 1.5 m, behind a small podium and used a computer keyboard to record the infant’s head turning behaviour.
The keyboard was hidden from the infant’s view at all times during testing. Two cabinets, each containing a sound speaker
(Bose 201-V) on a shelf above a 13-in. CRT computer monitor, were situated to the left and right side of the infant. Each
cabinet was positioned 90 cm on either side of the chair upon which the caregiver and infant were seated. Both computer
screens were oriented at a 90◦ angle from the infant, with the centre of the screen at approximately the infant’s eye level.
Both the caregiver and experimenter wore headphones throughout the experiment and listened to masking music to ensure
that the infant’s preferences were not influenced by those of the caregiver or experimenter.
All sound stimuli were played at a comfortable listening level by a Macintosh G4 computer, which was connected to a
Yahama amplifier/receiver, and in turn, connected to the two sound speakers. A Macintosh G4 computer, with customized
software, was located in an adjoining room and controlled the trial presentations and recorded looking times. Each infant
was randomly assigned to one song (either playsong or lullaby) and was tested on the two versions of that particular song.
1.3. Stimuli
The stimuli were four foreign children’s songs—one Spanish playsong, one French playsong, one Brazilian lullaby and
one Beninese (African) lullaby. A trained female singer recorded two expressive renditions of each song. The songs were
sung without accompaniment, in an expressive manner with their original foreign lyrics. A high- and low-pitch version
was recorded for each song, with the two versions differing in pitch by approximately a perfect 4th (5 semitones), which
is within the normal singing range of the singer. The pitch range of the playsongs and lullabies were similar, such that one
playsong and one lullaby each had pitch range spanning 7 semitones, while the other playsong and lullaby had a pitch range
spanning 13 and 12 semitones, respectively. Both playsongs were faster in tempo than both lullabies (72 and 76 beats per
minute for the playsongs versus 58 and 50 beats per minute for the lullabies). The two versions (high pitch and low pitch)
of each song were matched for tempo and timbre as closely as possible. Both playsongs and one lullaby were in the major
mode, and the other lullaby was in the minor mode. Both playsongs had more amplitude/intensity variation than either of
the lullabies. The songs were digitally recorded on an eMac G5 computer using Garageband 3 software. The stimuli were
recorded as digital audio files, and were accompanied by a visual display of a static image of the Disney character Goofy. The
same visual display was used for all songs.
1.4. Procedure
Prior to testing, caregivers were asked to complete a short questionnaire to determine the nature of infants’ experiences
with singing. This questionnaire asked what kind of songs caregivers typically sing to their infant (i.e., lullabies, playsongs,
popular radio songs) and also asked how frequently caregivers sang specific types of songs to their infants (i.e., daily, once
a week or less, rarely).
Infants were tested individually. The infant sat facing forward in the middle of the room on the caregiver’s lap. The
caregiver’s chair was located in the middle of the room between two cabinets. On top of each cabinet was a sound speaker
from which the auditory stimuli were played, and below each speaker was a CRT computer monitor on which the visual
target was displayed. The first trial began with the experimenter pressing a key on the keyboard when the infant was
attentive and facing forward. Once the trial had been initiated, the computer monitor on either the right or left side of the
infant flashed a visual stimulus of the Disney character Goofy. The flashing Goofy was used as a cue to orient the infant to
the side where the music would be playing from. When the infant looked to the flashing monitor, the experimenter pressed
a key on the keyboard and this started the timer for looking behaviour to be recorded by the computer (in seconds). At the
same time, Goofy stopped flashing, but remained on the screen and one of the song stimuli began to play. The trial ended
when the infant looked away (45◦ head turn) for at least 2 s. The experimenter then released the key, which extinguished
the image on the monitor and stopped the musical stimuli. The next trial consisted of the alternate version of the stimulus
and occurred on the opposite side. The same visual stimulus was presented on both monitors. For half of the infants, the
high-pitch version started on the right side, and for half of the infants it started on the left side. The high- and low-pitched
versions of the stimulus alternated until 20 trials were completed, or until 15 min had elapsed.
C.D. Tsang, N.J. Conrad / Infant Behavior & Development 33 (2010) 96–100
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Table 1
Percentage of caregivers who reported singing playsongs, lullabies and popular songs to their infant and the relative frequency of singing.
Frequency of singing
Lullabies
Playsongs
Popular songs
Daily
Less than once a week
Never
75
25
6
94
6
0
69
19
6
2. Results
Table 1 shows the type of songs and the percentage of caregivers who reported singing a particular song type to their
infants and how frequently they sung these songs. It should be noted that almost all caregivers reported singing both lullabies
and playsongs to their infants, and the majority of caregivers sing both song types to their infants on a daily basis. Only one
caregiver reported that she only sang playsongs daily and did not sing any lullabies to her infant.
Before testing whether infants showed significant preferences for high or low lullabies and playsongs, we wished to
establish whether there were effects of which pitch level was presented on each side, which pitch level was heard first, and
the sex of the infants. It was not possible to do a single analysis of variance (ANOVA) with all of these variables as they were
not completely crossed. However, an ANOVA was conducted with looking time to the pitch level as the dependent variable
and side of first presentation (left or right), pitch level heard first (high or low) as between-subject variables. No significant
effects were found. A second ANOVA with sex as a between-subjects factor showed no significant effects of sex. Thus, we
collapsed across side of first presentation, pitch level heard first, and sex in the subsequent analysis.
A 2 × 2 mixed ANOVA was conducted, with looking time (in seconds) as the dependent measure, pitch level (high or
low) as a within-subjects factor and song type (lullaby or playsong) as a between-subjects factor. The ANOVA revealed a
significant interaction between pitch level and song type, F(1, 14) = 19.50, p = .001. A paired samples t-test within pitch level
showed that infants looked longer to the low-pitched lullabies compared to high-pitched versions, t(7) = 4.46, p = .003, and
longer to high-pitched playsongs compared to low-pitched versions, t(7) = 2.25, p = .06 (Fig. 1).
3. Discussion
The current study shows that 6- and 7-month-old infants prefer low-pitch versions of lullabies and high-pitch versions
of playsongs. This extends the findings of Volkova et al. (2006), who found that infants showed a low-pitch preference for
unfamiliar lullabies. This result provides further evidence that the affective nature of music can have an effect on infant
pitch preferences and supports the notion that structural elements of musical stimuli can affect infants’ processing of music
(Saffran et al., 2005) which in turn affects infants’ pitch preferences. Together, the results suggest that infants may recognize
the affective state that songs attempt to communicate, and that this recognition may be based on the acoustical/performance
property of pitch.
Volkova et al. (2006) suggest that an alternative explanation for their finding of a low-pitch preference for lullabies is that
infants were demonstrating a novelty preference, because of infants’ relative infrequent exposure to lullabies in comparison
to playsongs. The results of our questionnaire suggest that although lullabies are sung slightly less than playsongs (a result
that is consistent with that of Trehub et al., 1997), in general the infants were quite familiar with caregivers singing lullabies
and playsongs, and therefore neither high nor low pitch is a particularly novel listening experience. Furthermore, the mean
total looking times to both lullabies and playsongs were relatively equivalent (49.80 and 45.38 s, respectively) and looking
times to high- and low-pitch versions were relatively equivalent (46.78 and 48.11 s, respectively), suggesting that a novelty
preference for less frequently heard lullabies is not apparent.
Fig. 1. Looking time (in seconds) to high- and low-pitch versions of the same lullaby or playsong. Error bars represent the standard error of the mean.
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C.D. Tsang, N.J. Conrad / Infant Behavior & Development 33 (2010) 96–100
The results presented in the current study show that the overall pitch of a song is communicative to infants. However, pitch
may not be the only performance property of music that conveys the message. Other performance or structural features, such
as tempo or timbre likely also communicate emotional information to infants. Infants’ memory representations for simple
melodies are tempo and timbre specific (Trainor, Wu, & Tsang, 2004) while representations for pitch are not (Plantinga &
Trainor, 2005) which suggests that infants’ processing of various structural elements of music are different. Furthermore both
tempo and timbre have been found to be related to specific affective messages, such as loving tone of voice and slow tempo
for soothing or comforting messages, and fast, clipped utterances when expressing fear or surprise (Fernald, 1991; Trainor,
Austin, & Desjardins, 2000). Indeed, it is possible that other non-pitch cues, such as tempo and/or intensity differences
between playsongs and lullabies, contributed to the communicative intent of the music stimuli in the present study. Thus, it
remains for future research to examine whether the convergence of the various structural and performance features of music
further enhance the message conveyed by the caregiver, and whether other features beyond pitch show similar effects.
Acknowledgements
This research was supported by a research grant from Huron University College at the University of Western Ontario. The
authors would also like to thank Jennifer Orr for her invaluable assistance with participant recruitment and testing, Josée
Viau-Boissoneault for her assistance with stimulus creation, and an anonymous reviewer for providing helpful comments
on an earlier draft.
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