Comparing Different Measures of Bilingual Input Derived From Naturalistic Daylong Recordings

Abstract

Purpose: Measuring language input, especially for infants growing up in bilingual environments, is challenging. Although the ways to measure input have expanded rapidly in recent years, there are many unresolved issues. In this study, we compared different measurement units and sampling methods used to estimate bilingual input in naturalistic daylong recordings. Method: We used the Language Environment Analysis system to obtain and process naturalistic daylong recordings from 21 French–English bilingual families with an infant at 10 and 18 months of age. We examined global and context-specific input estimates and their relation with infant vocal activeness (i.e., volubility) when input was indexed by different units (adult word counts, speech duration, 30-s segment counts) and using different sampling methods (every-other-segment, top-segment). Results: Input measures indexed by different units were strongly and positively correlated with each other and yielded similar results regarding their relation with infant volubility. As for sampling methods, sampling every other 30-s segment was representative of the entire corpus. However, sampling the top segments with the densest input was less representative and yielded different results regarding their relation with infant volubility. Conclusions: How well the input that a child receives throughout a day is portrayed by a selected sample and correlates with the child's vocal activeness depends on the choice of input units and sampling methods. Different input units appear to generate consistent results, while caution should be taken when choosing sampling methods. Supplemental Material: https://doi.org/10.23641/asha.22335688

Mixed-language input and infant volubility: Friend or foe?

“…Note that in these two studies, researchers measured the mixed-language input received in a specific context where one caregiver interacted with the child. Language input received in this type of one-on-one interaction plays an especially important role in children's language development (e.g., Ramírez-Esparza et al, 2017;Ruan, 2022;Ruan et al, 2020). However, because Place and Hoff did not include one-on-one mixing from caregivers other than the mother and they did not explore its relation with children's language skills before breaking down to different language categories, the question remains open as to whether the social contexts where mixed-language input is received modulate its relation with children's language development.…”

“…Given the strong association between language input and language acquisition, it is expected that input and volubility would also be related, although to date not much research has explored this possibility (Ramírez-Esparza et al, 2017;Ruan, 2022;Ruan et al, 2020). Regarding its relation with language input, infant volubility can be measured at two levels: overall and local (Ruan, 2022;Ruan et al, 2020). Infant overall volubility refers to infants' overall tendency to vocalize both during social interactions and when alone.…”

“…Local volubility, on the other hand, refers to infants' vocalizations produced in the presence of adult speech (Ruan, 2022;Ruan et al, 2020). Robust evidence shows that infants and caregivers' vocalizations mutually stimulate more vocalizations from each other and facilitate a social feedback loop (Athari et al, 2021;Goldstein et al, 2003;Goldstein & Schwade, 2008;Gros-Louis & Miller, 2018;Saint-Georges et al, 2013;Warlaumont et al 2014).…”

“…In our previous study, we analyzed naturalistic day-long recordings from French-English bilingual families with an infant at 10 and 18 monthsold and investigated the relation between French-or English-only input and infant volubility (Ruan, 2022;Ruan et al, 2020). As described above, infant volubility was measured at two levels: overall and local.…”

“…In the current study, we used the same recordings as our previous study (Ruan, 2022;Ruan et al, 2020) to investigate mixed-language input and its relation with infants' overall and local volubility. We also asked caregivers to estimate their use of language mixing via the Language Mixing Scale (Byers-Heinlein, 2013).…”