Prenatal daily musical exposure is associated with enhanced neural representation of speech fundamental frequency: Evidence from neonatal frequency-following responses

Abstract

Fetal hearing experiences shape the linguistic and musical preferences of neonates. From the very first moment after birth, newborns prefer their native language, recognize their mother's voice and show a greater responsiveness to lullabies presented during pregnancy. Yet, the neural underpinnings of this experience inducing plasticity have remained elusive. Here we recorded the frequency-following response (FFR), an auditory evoked potential elicited to periodic complex sounds, to show that prenatal music exposure is associated to enhanced neural encoding of speech stimuli periodicity, which relates to the perceptual experience of pitch. FFRs were recorded in a sample of 60 healthy neonates born at term and aged 12-72 hours. The sample was divided in two groups according to their prenatal musical exposure (29 daily musically exposed; 31 not-daily musically-exposed). Prenatal exposure was assessed retrospectively by a questionnaire in which mothers reported how often they sung or listened to music through loudspeakers during the last trimester of pregnancy. The FFR was recorded to either a /da/ or an /oa/ speech syllable stimulus. Analyses were centered on stimuli sections of identical duration (113 ms) and fundamental frequency (F0 = 113 Hz). Neural encoding of stimuli periodicity was quantified as the FFR spectral amplitude at the stimulus F0. Data revealed that newborns exposed daily to music exhibit larger spectral amplitudes at F0 as compared to not-daily musically-exposed newborns, regardless of the eliciting stimulus. Our results suggest that prenatal music exposure facilitates the tuning to human speech fundamental frequency, which may support early language processing and acquisition.