The development of emotional speech prosody perception in 3- to 14-month infants: a preferential listening study

Abstract

Developmental studies have shown strong evidence that socially enriched speech signal (including prosodic modifications) attracts infants’ attention and facilitates language development. While emotion understanding is evident at 9 months of age (Otte et al., 2015), the developmental trajectory of the emotional speech prosody perception is still unclear. The present study adopted a widely used preferential looking paradigm to measure 3- to 14-month-old infants’ listening preference to English words spoken in neutral, happy, angry, and sad tones. Analysis using a linear mixed model showed that infants’ preference of emotional prosody changed as a function of age. On average, the three-month olds listened longer to all emotional prosodies over the neutral one whereas older infants showed significantly diminished interests in the sad prosody, followed by the happy and angry voices. Around 12 months, infants appeared to listen to emotional prosodies equally with the exception of reduced interest in the angry prosody. These preferential listening measures were not correlated with the varying durations or fundamental frequencies of the spoken words for the different emotional categories, indicating that the development of emotional speech prosody is not purely driven by the acoustical properties but rather involves higher-order social cognition.