Infants tune up to music's core qualities

Babies may not know the difference between Beethoven and Boys II Men, but don't underestimate their musical judgment. Infants perceive pairs of musical tones just as adults do, finding certain acoustic duos pleasant and others jarring, a new study finds.

 People may possess innate brain mechanisms that consistently endow specific combinations of musical tones with either a dulcet or a distasteful sound, assert psychologists Marcel R. Zentner of the University of Geneva and Jerome A. Kagan of Harvard University.

 Certain pairs of musical tones differ in frequency, or number of sound waves per second, in such a way as to prove likable, or consonant, to adult ears when played together. Disparities between the frequencies of other pairs of tones are perceived as harsh, or dissonant.

 At 4 months of age, babies mirror the musical tastes of their elders by showing a clear fondness for consonant sounds and an abiding dislike for dissonant sounds, according to Zentner and Kagan's study.

"The human infant may possess a biological preparedness that makes consonance perceptually more attractive than dissonance," the researchers contend in the Sept. 5 Nature.

 Research conducted in the past several years by other scientists indicates that the ability to discriminate consonant from dissonant pairs of tones emerges by age 6 months.

"But this appears to be the first evidence suggesting that infants actually prefer consonance to dissonance," holds psychologist Laurel J. Trainor of McMaster University in Hamilton, Ontario.

 Zentner and Kagan studied 32 babies, all 4 months old, selected from white, middle-class families. During testing, each infant reclined in a flexible seat placed on a table and listened to music originating from a nearby speaker emblazoned with an eye-catching bull's-eye pattern.

 Infants heard 35-second segments adapted from two European folk songs, neither of which they had heard at home. Each segment consisted of pairs of notes played simultaneously by a music synthesizer.

 The researchers produced a consonant and a dissonant rendition of each tune. The versions were identical in tempo, rhythm, and all other respects except the frequency differences between the pairs of tones.

 Infants looked substantially longer at the bull's-eye pattern on the speaker, made fewer movements, and exhibited less fussiness while hearing the consonant melodies than when listening to the dissonant versions of the same tunes, Zentner and Kagan contend. This suggests that the babies preferred consonant melodies and experienced physiological arousal during the dissonant counterparts.

 Moreover, eight infants turned away from the speaker or emitted sounds of distress, such as whining, only during the dissonant versions. None of the infants reacted in these ways only to consonant renditions.

"These new findings are interesting, but they build on previous work pointing to an innate basis for musical perception," says psychologist Carol L. Krumhansl of Cornell University.

 For instance, Krumhansl and Peter W. Jusczyk of the State University of New York at Buffalo have found that by the age of 4 1/2 months, babies listen longer to Mozart minuets that have short pauses inserted between phrases, which musicians treat as "natural" segments of the musical flow, than to the same minuets with pauses placed in the middle of phrases.

 Other investigations indicate that 6-month-old infants prefer listening to musical scales sampled from a variety of cultures rather than to scales composed of randomly chosen notes.