An Association Between Phonetic Complexity of Infant Vocalizations and Parent Vowel Hyperarticulation.

Ellen Marklund,Lisa Gustavsson,Ulrika Marklund

doi:10.3389/fpsyg.2021.693866

Abstract

Extreme or exaggerated articulation of vowels, or vowel hyperarticulation, is a characteristic commonly found in infant-directed speech (IDS). High degrees of vowel hyperarticulation in parent IDS has been tied to better speech sound category development and bigger vocabulary size in infants. In the present study, the relationship between vowel hyperarticulation in Swedish IDS to 12-month-old and phonetic complexity of infant vocalizations is investigated. Articulatory adaptation toward hyperarticulation is quantified as difference in vowel space area between IDS and adult-directed speech (ADS). Phonetic complexity is estimated using the Word Complexity Measure for Swedish (WCM-SE). The results show that vowels in IDS was more hyperarticulated than vowels in ADS, and that parents’ articulatory adaptation in terms of hyperarticulation correlates with phonetic complexity of infant vocalizations. This can be explained either by the parents’ articulatory behavior impacting the infants’ vocalization behavior, the infants’ social and communicative cues eliciting hyperarticulation in the parents’ speech, or the two variables being impacted by a third, underlying variable such as parents’ general communicative adaptiveness.

Highlights

Infant-directed speech (IDS), the speech style commonly used when speaking to infants and small children (e.g., Soderstrom, 2007; Golinkoff et al, 2015), has been reported to facilitate or promote various aspects of early language development (e.g., Trainor and Desjardins, 2002; Singh et al, 2009; Ma et al, 2011; Bosseler et al, 2016; Foursha-Stevenson et al, 2017)
The way in which speech is realized is highly variable. Speakers adapt their articulation to the perceived demands of the listener (Lindblom, 1990), for example speaking more clearly in noisy environments (Šimko et al, 2016) or using more reductions when uttering semantically predictable words than when uttering unpredictable words (Clopper and Pierrehumbert, 2008). These adaptations mean that individual speech sounds are realized on a continuum that ranges from exaggerated articulation to relaxed articulation
The focus is articulatory adaptation of vowels, and it will be referred to as vowel hyperarticulation (VH), since vowels in infant-directed speech (IDS) to Swedish 12-month-old infants has previously been shown to be more hyperarticulated overall than vowels in Swedish adultdirected speech (ADS) (Marklund and Gustavsson, 2020)

Summary

INTRODUCTION

Infant-directed speech (IDS), the speech style commonly used when speaking to infants and small children (e.g., Soderstrom, 2007; Golinkoff et al, 2015), has been reported to facilitate or promote various aspects of early language development (e.g., Trainor and Desjardins, 2002; Singh et al, 2009; Ma et al, 2011; Bosseler et al, 2016; Foursha-Stevenson et al, 2017). Removing social feedback from adultinfant interaction leads to fewer vocalizations from 5-monthold infants (Goldstein et al, 2009), and providing social feedback in response to 8-month-old’s vocalizations results both in a higher number of vocalizations and more mature vocalizations (syllabic rather than vocalic, more canonical syllables, fully voiced) compared to social feedback noncontingent to infant productions (Goldstein et al, 2003) When it comes to vocal behavior, amount of parent IDS in parentinfant interactions correlates with amount of infant speech output (Dunst et al, 2012; Ramírez-Esparza et al, 2014; Spinelli et al, 2017). To investigate whether there is a link between parents’ articulatory adaptations and phonetic complexity of infants’ vocalization, the relationship between VSA difference between IDS and ADS, and infants’ mean WCM-SE score, was tested for correlation

Participants

DISCUSSION

ETHICS STATEMENT