Positive Valence Contributes to Hyperarticulation in Maternal Speech to Infants and Puppies

Abstract

Infant-directed speech often has hyperarticulated features, such as point vowels whose formants are further apart than in adult-directed speech. This increased “vowel space” may reflect the caretaker’s effort to speak more clearly to infants, thus benefiting language processing. However, hyperarticulation may also result from more positive valence (e.g., speaking with positive vocal emotion) often found in mothers’ speech to infants. This study was designed to replicate others who have found hyperarticulation in maternal speech to their 6-month-olds, but also to examine their speech to a non-human infant (i.e., a puppy). We rated both kinds of maternal speech for their emotional valence and recorded mothers’ speech to a human adult. We found that mothers produced more positively valenced utterances and some hyperarticulation in both their infant- and puppy-directed speech, compared to their adult-directed speech. This finding promotes looking at maternal speech from a multi-faceted perspective that includes emotional state.

Models of human learning should capture the complexity of natural communication

“…Caregivers also frequently change their facial movements and tone of voice to convey emotion. When caregivers address infants, they use exaggerated facial displays of emotion, sometimes called "emotionese" (Brand et al, 2002;Kosie & Lew-Williams, 2023;Wu et al, 2021), and a happy vocal tone (Fernald, 1992;Fernald et al, 1989;Kitamura & Burnham, 2003;Panneton et al, 2023;Singh et al, 2002;Trainor et al, 2000). Researchers are just beginning to characterize the kinds of emotion displays that infants observe in their natural environmentsfor instance, Ogren et al (2023) found that despite researchers' overwhelming focus on canonical facial displays (like furrowing brows for anger or pouting for sadness), infants rarely see facial configurations that match these patterns in real-world settings.…”