Music and speech input in the home environments of Latinx infants.

Infants' experience with the auditory world is culture-specific and shapes how their brains process complex sounds in their environment. The present study is the first to examine naturalistic exposure to speech and music, two main components of infants' auditory soundscapes, in Latinx U.S. infants (n = 64; age range 4-23mo). Through a bootstrapping approach, results are then compared to a previously published dataset of non-Latinx U.S. infants. Two daylong audio recordings per infant were captured with LENA. Using a crowdsourcing approach, 417 naïve listeners annotated a total of 6400 randomly sampled short audio snippets through an online citizen science platform. Latinx infants received more speech input than music input, replicating previously published results with non-Latinx infants. Likewise, as was the case for non-Latinx infants, Latinx infants were exposed to more music from an electronic source than an in-person source; a pattern that was again reversed for speech. However, while non-Latinx infants experienced more non-infant-directed (non-ID) music compared to infant-directed (ID) music, the opposite was true for Latinx infants: they experienced more ID music compared to non-ID music. Latinx infants also experienced overall more music, and more ID music, compared to their non-Latinx counterparts. Together, these results point to nuanced but important differences between the auditory environments of Latinx and non-Latinx infants. Enhanced exposure to ID music in the Latinx group may act as a promotive factor in a range of developmental areas and should be considered when evaluating infants' auditory environments.