Parents’ hyper-pitch and vowel category compactness in infant-directed speech are associated with 18-month-old toddlers’ expressive vocabulary ...

• Main Authors: Rosslund, Audun, Mayor, Julien, Óturai, Gabriella, Kartushina, Natalia
• Format: Article in Journal/Newspaper
• Language: English
• Published: Carnegie Mellon University Library Publishing Service 2022
• Subjects: FOS Psychology; infant-directed speech; language acquisition; Norwegian language acquisition; Northern Norway; Tromsø
• Online Access: https://dx.doi.org/10.34842/2022.0547; https://lps.library.cmu.edu/LDR/article/id/547/

The present study examines the acoustic properties of infant-directed speech (IDS) as compared to adult-directed speech (ADS) in Norwegian parents of 18-month-old toddlers, and whether these properties relate to toddlers’ expressive vocabulary size. Twenty-one parent- toddler dyads from Tromsø, Northern Norway participated in the study. Parents (16 mothers, 5 fathers), speaking a Northern Norwegian dialect, were recorded in the lab reading a storybook to their toddler (IDS register), and to an experimenter (ADS register). The storybook was designed for the purpose of the study, ensuring identical linguistic contexts across speakers and registers, and multiple representations of each of the nine Norwegian long vowels. We examined both traditionally reported measures of IDS: pitch, pitch range, vowel duration and vowel space expansion, but also novel measures: vowel category compactness and vowel category distinctiveness. Our results showed that Norwegian IDS, as compared to ADS, had similar characteristics as ...