Perceptual difficulty in discerning speech sounds (Hendrickson et al., 2025)

Purpose: Utilizing psycholinguistic methods, this article aims to ascertain the perceptual difficulty associated with distinguishing between different speech sound categories and individual contrasts within those categories, with the ultimate goal of informing the use of minimal pair contrasts in perceptual training.

Design: Using eye-tracking in the Visual World Paradigm, adults with normal hearing (N = 30) were presented with an auditory word and were required to identify the matching image from a selection of four options: the target word, two unrelated words, and a minimal pair competitor contrasting with the target word in word-final position in one of four categories (manner, place, voicing, nasality).

Results: We measured fixations to minimal pair competitors over time and found that manner and place competitors exhibited greater competition compared to voicing and nasality competitors. Notably, within manner competitors, substantial differences in discrimination difficulty were observed among individual contrasts.

Conclusions: Conventional views of speech sound perception have often grouped sounds into broad categories (manner, place, voicing, nasality), potentially overlooking the nuanced differences within these groupings, which significantly affect perception. This work is vital for advancing our understanding of speech perception and its mechanisms. Furthermore, this work will help to refine minimal pair treatment strategies in clinical contexts.

Supplemental Material S1. A dataset reporting measures of duration, mean intensity, and formant frequencies (F0, F1, F2, F3) for the vowel and coda consonant of each minimal pair.

Hendrickson, K., Lee, N., Walker, E. A., Foody, M., & Combiths, P. (2025). Assessing perceptual difficulty across speech sound categories and contrasts to optimize minimal pair training. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2025_JSLHR-24-00254