Acquiring a Vowel System in Motion: Preschoolers and the NZE Expanded Short Front Vowel Shift

Joshua Wilson Black (a), Lynn Clark (a, b), and Gia Hurring (a)

a: New Zealand Institute of Language, Brain and Behaviour, University of Canterbury.

b: Department of Linguistics, University of Canterbury.

Under review

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Abstract

The New Zealand English (NZE) vowel system exhibits both variability and complex systematicity. Recent work shows that vowels involved in the NZE short front vowel shift (i.e. TRAP, DRESS, & KIT) covary with other vowels (especially FLEECE and NURSE; see Brand et al. (2021)) and that covariation remains intact even as individual vowels in this cluster stabilise or change direction (Hurring et al. 2025). We explore what happens when children acquire their accent in such a complex environment. We apply acoustic phonetic methods to a corpus of preschool children (n=124, 3;11-5;5) from Christchurch, New Zealand and a community corpus of adult talkers (n=345). We consider the vowels associated with this cluster of covariation. We find that children produced more conservative vowels than expected, sometimes diverging from community changes in progress. Vernacular reorganisation, developmental effects, hyperarticulation, and priming are considered as explanations for the patterns we see in developing vowel spaces.

How to use the GitHub repository

The main entry point to this project is the OSF.io page at https://osf.io/cz3jt/.

The simplest way to use this material is to view the supplementary files using your web browser. The benefit of this is that you can easily see the commentary and the code and do not have to run it yourself (which takes a long time). The disadvantage is, correspondingly, that you cannot step through each step in your own R session or see what happens if you modify the code. The web versions of the supplementary materials are available at:

1. Filtering and Formant Tracking
2. Modelling

This repository (the GitHub repository) provides access to the majority of the code and data for the project. To fully retrace our steps, you will also need:

1. Acquire prefit models from the OSF repository. Models are stored here at OSF as a '.rds' file, which is openable by R using the base R readRDS function or readr::read_rds. The models reported in the paper and supplementary material are also available in OSF storage. Place models in a directory called 'models' in the project directory (i.e. the base directory of the git repository, if you cloned the repository from GitHub, or the directory which was generated when you unzipped the ZIP file you downloaded from GitHub.

2. Acquire praat.zip from the OSF repository and unzip it in the project directory. SM1_formants.html, linked above, describes a process for validating formant tracking settings. The file praat.zip contains the files produced in this process and is necessary for SM1_formants.html to be produced from the qmd file.