Musical Intervals in Infants’ Spontaneous Crying over the First 4 Months of Life

Abstract

<b><i>Introduction:</i></b> Perception and memorizing of melody and rhythm start about the third trimester of gestation. Infants have astonishing musical predispositions, and melody contour is most salient for them. <b><i>Objective:</i></b> To longitudinally analyse melody contour of spontaneous crying of healthy infants and to identify melodic intervals. The aim was 3-fold: (1) to answer the question whether spontaneous crying of healthy infants regularly exhibits melodic intervals across the observation period, (2) to investigate whether interval events become more complex with age and (3) to analyse interval size distribution. <b><i>Methods:</i></b> Weekly cry recordings of 12 healthy infants (6 females) over the first 4 months of life were analysed (6,130 cry utterances) using frequency spectrograms and pitch analyses (PRAAT). A preselection of utterances containing a well-identifiable, noise-free and undisturbed melodic contour was applied to identify and measure melodic intervals in the final subset of 3,114 utterances. Age-dependent frequency of occurrence of melodic intervals was statistically analysed using generalized estimating equations. <b><i>Results:</i></b> 85.3% of all preselected melody contours (<i>n</i> = 3,114) either contained single rising or falling melodic intervals or complex events as combinations of both. In total 6,814 melodic intervals were measured. A significant increase in interval occurrence was found characterized by a non-linear age effect (3 developmental phases). Complex events were found to significantly increase linearly with age. In both calculations, no sex effect was found. Interval size distribution showed a maximum of the minor second as the prevailing musical interval in infants’ crying over the first 4 months of life. <b><i>Conclusion:</i></b> Melodic intervals seem to be a regular phenomenon of spontaneous crying of healthy infants. They are suggested to be a further candidate for developing an early risk marker of vocal control in infants. Subsequent studies are needed to compare healthy infants and infants at risk for respiratory-laryngeal dysfunction to investigate the diagnostic value of the occurrence of melodic intervals and their age-depending complexification.

Melody complexity of infants’ cry and non-cry vocalisations increases across the first six months

“…In agreement with preceding studies 17 , 44 , 45 , 58 , a complex melody structure was defined as exhibiting ≥ two arcs and/or intra-melodic breaks between arcs by glottal oscillatory pauses or marked laryngeal constrictions that generate rhythmical variations of the acoustic Gestalt. Examples for rhythmic variations of complex (multiple-arc melodies) are available in several previous publications 37 , 45 , 58 , 89 .…”

“…The essential characteristic of IDS is the emotional content conveyed via melody, rather than words. The well-developed perception of melody and rhythm in the foetus 30 , newborn 31 – 33 and young infant 21 , 34 – 37 leaves no doubt that the human infant has a specific sensitivity to musical sound features 36 , 38 – 40 .…”

“…This view has since been refuted 35 , 44 , 45 , 49 , 72 – 78 . The mitigated, melodic cries of human infants are at some level, similar to simple musical melodies (“glissandi smoothly slurred or swept over a certain frequency interval” 17 ; p.643) and could provide raw material for prosodic constituents of later language 17 , 37 , 58 . The same is true for prosodic properties of non-cry vocalisations.…”