Tonal synchrony in mother-infant interaction based on harmonic and pentatonic series

Infant Behav Dev. 2010 Dec;33(4):387-400. doi: 10.1016/j.infbeh.2010.04.003. Epub 2010 May 15.


This study reports the occurrence of 'tonal synchrony' as a new dimension of early mother-infant interaction synchrony. The findings are based on a tonal and temporal analysis of vocal interactions between 15 mothers and their 3-month-old infants during 5 min of free-play in a laboratory setting. In total, 558 vocal exchanges were identified and analysed, of which 84% reflected harmonic or pentatonic series. Another 10% of the exchanges contained absolute and/or relative pitch and/or interval imitations. The total durations of dyads being in tonal synchrony were normally distributed (M=3.71, SD=2.44). Vocalisations based on harmonic series appeared organised around the major triad, containing significantly more simple frequency ratios (octave, fifth and third) than complex ones (non-major triad tones). Tonal synchrony and its characteristics are discussed in relation to infant-directed speech, communicative musicality, pre-reflective communication and its impact on the quality of early mother-infant interaction and child's development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Auditory Perception / physiology*
  • Child Development*
  • Communication*
  • Female
  • Humans
  • Imitative Behavior / physiology
  • Infant
  • Longitudinal Studies
  • Male
  • Mother-Child Relations*
  • Mothers / psychology
  • Play and Playthings