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Word learning, Phonology, Processing, Prosody


Children are adept at learning their language’s speech-sound categories, but just how these categories function in their developing lexicon has not been mapped out in detail. Here, we addressed whether, in a language-guided looking procedure, two-year-olds would respond to a mispronunciation of the voicing of the initial consonant of a newly learned word. First, to provide a baseline of mature native-speaker performance, adults were taught a new word under training conditions of low prosodic variability. In a second experiment, 24- and 30-month-olds were taught a new word under training conditions of high or low prosodic variability. Children and adults showed evidence of learning the taught word. Adults’ target looking was reduced when the novel word was realized at test with a change in the voicing of the initial consonant, but children did not show any such decrement in target fixation. For both children and adults, most learners did not treat the phonologically distinct variant as a different word. Phonetic variability during teaching did not have consistent effects. Thus, under conditions of intensive short-term training, 24- and 30-month-olds did not differentiate a newly learned word from a variant differing only in consonant voicing. High task complexity during training could explain why mispronunciation detection was weaker here than in some prior studies. We also tested 19-month-olds in the low-variability condition, because we originally predicted that children would learn words and detect one-feature mispronunciations as early as 19 months. However, 19-month-olds showed inconsistent word learning, suggesting that the narrated story we used for word teaching might have been too complex. Thus, in the article we focus on the work with 24- and 30-month-olds, presenting the 19-month-olds’ results in the Supplemental Materials. Their data are included in the data file in the interests of transparency. The Supplemental Materials accompanying the paper also report analyses of (lack of) responses to pitch mispronunciations by adults and 19-month-olds. Adults were tested with both pitch and consonant MPs. Nineteen-month-olds were tested with one or the other, due to more limited attention spans.


The data supports a manuscript: Quam, C., & Swingley, D. (2022). A protracted developmental trajectory for English-learning children’s detection of consonant mispronunciations in newly learned words. Language Acquisition, 1-21.

The author's manuscript version of the article is available in PDXScholar:

Data Description:
The data file is in CSV format and can be opened in Microsoft Excel or (for example) read into the statistical program R via the command read.csv

Participants are English-speaking and were tested in an eye-tracking experiment. Four ages were recruited: 19 months, 24 months, 30 months, and adults. Participants were recruited in Philadelphia, PA, USA. Adults were recruited from the University of Pennsylvania community. Children were recruited from the broader local community. In an eye-tracked laboratory study comprising a single session, all participants were taught a novel word, deebo, and then tested on correct pronunciations, initial-consonant mispronunciations, and/or pitch mispronunciations. Each row contains one participant’s data. Columns are as follows:

  1. Participant/subject ID numbers (“subj”)
  2. “MP_type” indicates whether each child was in the pitch-mispronunciation (“inton”, for intonation MP) or consonant-mispronunciation (“seg”, for segmental MP) condition. Adults heard both MPs (“intonSeg”).
  3. “Cond” indicates whether participants heard the low prosodic variability training (“lowVar”) or the high prosodic variability training (“highVa”)
  4. “AgeCat” indicates the age group (19, 24, 30, or adult)
  5. “AgeDays” indicates the precise age in days for each child.
  6. “pitchInTest” indicates which pitch contour was presented in the test phase (in CP and consonant MP trials), the rise-fall (“rise”) or low fall (“fall”). For low-variability participants, this was the same pitch contour used in training.
  7. “object” indicates whether the deebo was the purple disk-like object (“disk”) or the red knobby object (“knobs”).
  8. “gender” indicates the participant’s gender as reported by parents or adult participants.
  9. target-fixation proportions averaged over 367-2000 ms. after noun onset (for children) or 200-2000 ms. after noun onset (for adults). Target-fixation proportions are averaged over trials of the following types: “filler” (familiar-word) trials;
  10. correct-pronunciation trials (“CP”);
  11. consonant-mispronunciation (“MP_cons”); and
  12. pitch-mispronunciation (“MP_pitch”) trials.
  13. Preference-corrected target-fixation proportions (“preCorr”) are also reported for fillers;
  14. CP_preCorr;
  15. seg_preCorr (consonant-MP)
  16. pitch_preCorr (pitch-MP)
  17. vocab: “understands and says” from mCDI (children only)
  18. firstMP: which MP adults heard first in the test phase (pitch or “seg”, AKA, consonant)


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