Year: 2020
Type: book
Abstract: Child speech is highly variable.The speech apparatus-the vocal tract, tongue, teeth, and vocal folds-develop at different rates for different children, which helps explain some of the variability in children's speech.For example, the ratio of the oral to pharyngeal cavities changes as children age, making it difficult to establish reliable articulatory routines (Smith and Goffman 1998;Vorperian et al. 2005).While anatomy does play this undeniable role in child speech development, this dissertation focuses instead on components in the child's environment that may explain their speech patterns.To do so, the studies here report on speech development in bilingual children acquiring South Bolivian Quechua (henceforth "Quechua") and Spanish in a mid-size town in Bolivia.Chapters 2 and 3 examine the environmental effect of Quechua's linguistic structure on speech development while chapter 4 examines the role of quantity of language exposure.Chapter 2 examines how a phonological factor -vowel inventory-interacts with speech development.In Quechua, there are just three phonemic and two allophonic vowels.Chapter 2 asks if vowel inventory size mitigates acoustic variability in children aged four through ten.The study finds that children as young as four approximate adult-like acoustic targets, suggesting that child speech variability is contingent upon the language being learned.Still, children do not necessarily speak like adults.Using these vowel data, chapter 2 additionally finds that the children vary greatly in their ability to articulatorily compensate for their vocal tract morphologies, potentially explaining some of the large amounts of between-speaker variation that characterizes child speech.Chapter 3 examines how another aspect of Quechua's linguistic structure -its highly agglutinating morphology -may interact with speech development.In Quechua, speakers construct words by supplementing root morphemes with a series of grammatical suffixes.Chapter 3 asks if this word composition could interact with children's coarticulatory patterns.Here coarticulation is quantified using two novel acoustic measures that are less susceptible to the challenges that the child vocal anatomy poses for traditional spectral analysis.In experiment 2 of chapter 3, these measures are validated on a large corpus of four-year-old children acquiring English.The central results of chapter 3 demonstrate that children and adults distinguish coarticulatorily between word environments: within morpheme (e.g.papa 'potato') and between morpheme (e.g.papa-pi 'potato-loc).However, only children compensate for the morphologically complex words' There are many people without whom this dissertation, and my development as an independent researcher and fieldworker, would not have been possible.Thank you to my community in Bolivia.Ana Torres and René Iglesias welcomed me into their home and helped me form a partnership with the primary school.I'm grateful to that school for allowing me to work with and learn from the students and faculty.This dissertation is dedicated to all of the mothers and matriarchs in Bolivia who graciously lent me their time, attention, and expertise to contribute to the daylong recording corpus.The quantity of data-much of it naturalistic!-analyzedfor this project might not have been completed without my stellar group of research assistants.Karina Fong-Hirschfelder, Sierra Adachi, Rachel Elia, Kiran Girish, Hitomi Torng, and Sonnet Phelps all contributed to data pre-processing, coding, sorting, plotting-you name it, in addition to giving me frank and necessary feedback.I loved our monthly team dinners and hope they learned as much from me as I did from them.I have learned and developed so much from working with the members of the Daylong Audio Recording of Children's Linguistic Environments (DARCLE) community.In particular I thank Adriana Weisleder, Amanda Seidl, and especially Alex Cristia and Middy Casillas.Chapter 4 of this dissertation, and my fieldwork with children in Bolivia, would not have happened without Alex and Middy's guidance and feedback.To members of my Maryland community: Michele Erskine, Allie Johnson, Tatiana Thonsevanh, and Katie Von Holzen, all of whom helped me get out of my linguistics box.And to my Berkeley community: Sarah Bakst, for always
Author: Margaret Cychosz
Language: English
Subfield: Experimental and Cognitive Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W3084518943