Exploring infant talker bias: Insights from remote speech perception testing

Abstract

Lab studies show that infants (4- to 7-month-olds) prefer to listen to vowels with infant-like f0 and formant frequencies over those of an adult female (Masapollo et al., 2015; Polka et al., 2021). This Infant Talker Bias may facilitate infants’ mapping of articulatory gestures to acoustic correlates. In this study, 4- to 12-month-olds completed a listening preference task on the Lookit online testing platform. Across eight trials, we presented synthesized infant and adult vowel sounds (/i/ and /a/) paired with a simple animation and recorded the infant’s response via the webcam. Infant looking time and vocalization to each vowel type were coded offline. Preliminary analyses (n = 91) show that listening time increased with age (p < 0.05), and all infants listened longer to infant vowels than to adult vowels (p < 0.01). Preliminary analyses (n = 62) also show an increase in infant vocalizations with age (p = 0.00) and a trend towards more and longer vocalizations in response to the adult vowels. These findings replicate and extend the infant talker bias to new vowel stimuli and to older infants, and support the use of remote testing in infant speech perception studies.