than for preschool audiences, and the articulation of lyrics is more slurred for infants than
for preschoolers.^117 Expressive features of the ‘maternal’style are also evident when fathers
sing to their infant offspring116,118,119and when preschoolers sing to their infant siblings.^120
There are parallels between maternal speech and singing to infants,12,51,104but there are
differences as well. In general, women’s singing is higher pitched than their speech, but
maternal speech to infants is higher pitched than maternal singing.^121 This situation results
from a three- to four-semitone increase in pitch level when mothers speak to infants,^122 in
contrast to an increase of approximately one-semitone when they sing to infants.114,116
Despite considerable variation across mothers, there is dramatic intra-individual consist-
ency. When mothers sing the same song to infants on different occasions separated by a
week or more, their pitch level and tempo (see Table 1.1) are virtually identical.^121
Variations in mothers’pitch and tempo are smaller than those observed in adults’repeated
renditions of pop or folk songs.63,123,124By contrast, mothers’repeated utterances to infants
exhibit large variations in pitch and tempo (see Table 1.1) but relatively stable rhythms. If
singing to infants affects maternal mood or state, it could contribute to the stability of pitch
and tempo over extended periods—a possible consequence of mood-dependent
memory.^125 Frequent singing to infants may also implicate motor memory. In any event,
mothers’sung performances seem to become ritualized, which could promote infants’
recognition of mother’s voice and the songs she sings.
Responsiveness to maternal music
How do infants respond to these maternal singing rituals? In the newborn period and
beyond, infants listen significantly longer to audio recordings of infant-directed singing
than to typical informal singing.126,127They also exhibit greater attention to higher- than
to lower-pitched versions of the same song.^128 These preferences indicate the potency of the
maternal style of singing, even in the absence of the familiar voice and expressive gestures
that typically accompany maternal performances.
10
Table 1.1 Absolute pitch and tempo differences for mothers’infant-directed
speech and singing across weeks
Mother Pitch (semitones) Tempo (beats per minute)
Speech Singing Speech Singing
1 4.0 1.0 16 0
2 6.0 0.0 32 4
3 5.0 1.0 6 0
4 3.0 2.0 32 6
5 4.0 0.0 88 0
6 4.5 0.0 0 0
7 5.5 0.0 4 12
8 16.0 0.0 16 0
9 6.5 3.0 18 18
10 0.0 0.0 8 0
11 0.0 1.0 31 0