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Of particular interest is the question of which aspects of music are represented in
infants’ memories. Any given musical experience contains information which is relevant
for discerning the deep structure of the piece, including its melodic structure, harmonic
structure, and rhythm. There is also myriad information which is less important musically,
such as the specific key of the piece, the exact tempo of the performance, and the instru-
ments upon which it is played. Despite the seeming irrelevance of these highly specific
aspects of particular musical experiences, adult listeners’ representations of highly familiar
pieces include information about absolute pitch,^12 absolute tempo,^13 and timbre.^14 It
appears that at least for adult listeners, ‘memory representations for complex auditory
stimuli contain information about the absolute properties of the stimuli, in addition to
more meaningful information abstracted from the relations between stimulus compon-
ents’^14 (p. 646). This model of auditory memory also captures what is currently known
about adult representations of linguistic auditory events, which include seemingly irrelev-
ant specific information such as talker-specific cues as well as linguistically meaningful
information; for example, adult listeners appear to include speaker voice and rate (though
not amplitude) in their representations of spoken words.^15
Which aspects of auditory experiences are represented by infant listeners in memory?
Research focused on infant speech perception suggests that infants as young as 7.5 months
of age can reliably remember new words after just a few exposures embedded in fluent
speech, and that these representations are specific enough that infants exposed to ‘cup’ do
not incorrectly recognize ‘tup’ (e.g. Ref. 16). Moreover, infants at this age can remember
words heard multiple times in stories over multi-week delays.^17 Even younger infants can
recognize their names and other words that are heard frequently in their environments
(e.g. Refs 18 and 19). The literature also provides some indications that like adults, infants
represent multiple levels of auditory stimuli, including both those that are linguistically rel-
evant and those that are not. For example, 7.5-month-old infants include talker-specific
cues in their representations of spoken words.^20 However, infants are able to ignore talker-
specific properties under other circumstances—in particular, infants readily exhibit vowel
normalization, categorizing individual exemplars according to vowel identity despite dif-
ferences in speaker sex (e.g. Refs 21 and 22). Infants thus appear to process linguistic aud-
itory events at multiple levels of detail simultaneously.
These findings from the domain of speech suggest potential avenues of study for infant
musical learning and memory. Is infant memory for musical experiences as powerful and
as detailed as memory for language? It is possible that infants’ representations of music are
even more specific than their representations of speech; mothers’ songs to infants are
remarkably consistent over time with respect to their pitch and tempo, providing a highly
reliable set of musical cues to infant listeners, whereas their infant-directed-speech is less
consistent in pitch and tempo.^23
To learn about music, infants must acquire knowledge both about musical structure in
general and about specific pieces of music. The literature suggests that the former process—
learning one’s native musical system—is quite extended developmentally. Indeed, while
there are some indications that infants acquire rudimentary knowledge about how tonal
systems work during their first year of life (e.g. Ref. 24), most of this knowledge is not
fully acquired until childhood (e.g. Refs 25–27). For example, Schellenberg and Trehub^28