2018 Friday Poster 6422

Friday, November 2, 2018 | Poster Session I, Metcalf Small | 3pm

Acquisition of Plural Morphology by Preschoolers with Hearing Loss
B. Davies, N. Xu Rattanasone, K. Demuth

Young children may spontaneously produce plural words such as cats, but may initially treat them as lexical wholes, rather than as morphologically complex words (e.g., cat+s). This raises questions about when children acquire knowledge of productive plural morphology. In English, the plural has three different allomorphs. Children with normal hearing (NH) are reported to produce the segmental allomorphs (/s/, /z/; cats, dogs) before the lower-frequency syllabic allomorph (/əz/; buses)[1,2,3,4]. Comprehension tasks also show earlier sensitivity to the segmental plural[5] compared to the syllabic plural[6]. Children with hearing loss (HL) face challenges in acquiring the plural[7,8], probably due to difficulties with perceiving fricatives[10]. We therefore anticipated that, due to the greater perceptual salience of the syllabic plural, children with HL might be better able to comprehend this allomorph. This seems to be the case in their production of familiar words[10]. This study therefore explored the comprehension of novel singular and plural words by preschoolers with NH and HL, testing productive knowledge of plural morphology using a novel word two-alternative forced choice task.

Participants were 129 children with NH, aged 36–67 months (M=48.89) and 27 children with mild to profound pre-lingual HL, aged 38–82 months (M=50.11), fitted bilaterally with hearing aids (n=14), cochlear implants (n=10) or bimodally with one of each (n=3). All participants were monolingual English speakers and could perceive spliced plural morphemes in isolation.

Pictures were displayed side-by-side on an iPad[11]. One depicted a singular novel animal/object and the other depicted five novel animals/objects. An auditory stimulus instructed children to touch the [novel word]. Segmental plurals took the form of CVCs/z (e.g., teps), and syllabic plurals took the form of CVCəz (e.g., kosses).

A binomial generalized linear mixed-effect model was fitted[12] with fixed effects and interactions (intercepts underlined) of Allomorph (segmental/syllabic), Number (singular/plural) and Group (NH/HL). A fixed effect for Age was included. Random slopes and intercepts for Participant were included. Results are on Table 1. Post-hoc analyses revealed significant differences between Groups for plurals (segmental: z=4.46, p<.001; syllabic: z=5.11, p<.001), but not for singulars (segmental: z=1.76, p=.29; syllabic: z=2.40, p=.08). Significant differences between singulars and plurals were found for NH children (segmental: z= -3.27, p<.001; syllabic z=6.98, p<.001), but not for those with HL (segmental: z=1.41, p=.49; syllabic z=4.70, p=.96). Planned t-tests revealed NH children were significantly above chance for all conditions, while children with HL were not (fig 1). Significant correlations between Accuracy and Age were found for both Groups, but only for plurals (fig 2).

Contrary to our prediction, the results showed that allomorph type had no effect on plural comprehension for the children with HL; they were at chance for both the segmental and syllabic plural. However, for both the NH children and those with HL, plural comprehension with novel words improved with age. This suggests that HL delays children’s acquisition of plural morphology, raising questions about when this becomes productive. Implications for word-learning and lexical representations as a function of degree of HL and fitting type are discussed.

References

  1. Brown, R. (1973). A first language: The early stages. Cambridge, MA: Harvard University
  2. de Villiers, J. G., & de Villiers, P. (1973). A cross-sectional study of the acquisition of grammatical morphemes in child speech. Journal of Psycholinguistic research, 2(3), 267-278.
  3. Mervis, C. B., & Johnson, E. (1991). Acquisition of the plural morpheme: A case study. Developmental psychology, 27(2), 222235.
  4. Berko, (1958). The child’s learning of English morphology (Doctoral dissertation, Radcliffe College.).
  5. Daves, B., Xu Rattanasone, N., & Demuth, (2017). Two-Year-Olds’ Sensitivity to Inflectional Plural Morphology: Allomorphic Effects. Language Learning and Development. 13(1), 38-53.
  6. Kouider, S., Halberda, J., Wood, J., & Carey, S. (2006). Acquisition of English number marking: The singular-plural distinction. Language Learning and Development, 2(1), 1-25.
  7. Koehlinger, M., Van Horne, A. J. O., & Moeller, M. P. (2013). Grammatical outcomes of 3-and 6-year-old children who are hard of hearing. Journal of Speech, Language, and Hearing Research, 56(5), 1701-1714.
  8. McGuckian, M., & Henry, (2007). The Grammatical Morpheme Deficit in Moderate Hearing Impairment. International Journal of Language & Communication Disorders, 42, 17-36.
  9. Pittman, L., Stelmachowicz, P. G., Lewis, D. E., & Hoover, B. M. (2003). Spectral characteristics of speech at the ear: Implications for amplification in children. Journal of Speech, Language, and Hearing Research, 46(3), 649-657.
  10. Koehlinger, K., Van Horne, O., Oleson, J., McCreery, R., & Moeller, M. P. (2015). The role of sentence position, allomorph, and morpheme type on accurate use of s-related morphemes by children who are hard of hearing. Journal of Speech, Language, and Hearing Research, 58(2), 396-409.
  11. Rattanasone, N. X., Davies, B., Schembri, T., Andronos, F., & Demuth, (2016). The iPad as a Research Tool for the Understanding of English Plurals by English, Chinese, and Other L1 Speaking 3-and 4-Year-Olds. Frontiers in Psychology, 7.
  12. Bates, D., Mächler, M., Bolker, B., & Walker, S. (2015). Fitting Linear Mixed-Effects Models Using lme4. Journal of Statistical Software, 67(1), 1–48.