The Influence of Prenatal Language Exposure on the Use of Pitch in Newborns’ Vocalisations: A Systematic Review

Abstract

Prenatal language exposure has been shown to influence early speech perception, with evidence suggesting that the acquisition of certain aspects of native-language prosody may begin before birth. While this notion has been well-supported from a perceptual perspective, findings across available production studies are inconsistent. This study, therefore, explored whether the pitch of newborns’ early vocalisations is influenced by prenatal exposure to their native language via a systematic review of quantitative evidence. The review included 18 studies analysing the pitch patterns of cry and non-cry vocalisations in healthy newborns aged birth to 3 months with monolingual prenatal exposure to 11 languages. It systematically describes the study characteristics and outcomes of these studies and synthesises the converging and diverging trends across them through cross-linguistic comparisons. Within this sample, the available evidence for cross-linguistic differences in the pitch patterns of early vocalisations is sparse and inconsistent. Importantly, substantial variations in the analysis methods used across studies were noted, which further obscure cross-studycomparisons. Furthermore, studies were restricted in number as well as the diversity of languages and vocalisation types represented. Taken together, our review suggests that there is at best tentative evidence for an influence of prenatal language exposure on newborns’ pitch production. Based on this review, we offer recommendations to improve the replicability and representativeness of future research, with the aim of arriving at a more definitive answer to the research question.