The acquisition of acoustic cues to onset and coda voicing contrasts by preschoolers with hearing loss

Purpose
Children with hearing loss (HL), including those with hearing aids (HAs) and cochlear implants (CIs), often have difficulties contrasting words like “beach” versus “peach” and “dog” versus “dock” due to challenges producing systematic voicing contrasts. Even when acoustic contrasts are present, these may not be perceived as such by others. This can cause miscommunication, leading to poor self-esteem and social isolation. Acoustic evidence is therefore needed to determine if these children have established distinct voicing categories before entering school and if misperceptions are due to a lack of phonological representations or due to a still-maturing implementation system. The findings should help inform more effective early intervention.

Method
Participants included 14 children with HL (eight HA users, five CI users, and one bimodal) and 20 with normal hearing, all English-speaking preschoolers. In an elicited imitation task, they produced consonant–vowel–consonant minimal pair words that contrasted voicing in word-initial (onset) or word-final (coda) position at all three places of articulation (PoAs).

Results
Overall, children with HL showed acoustically distinct voicing categories for both onsets and codas at all three PoAs. Contrasts were less systematic for codas than for onsets, as also confirmed by adults' perceptual ratings.

Conclusions
Preschoolers with HL produce acoustic differences for voiced versus voiceless onsets and codas, indicating distinct phonological representations for both. Nonetheless, codas were less accurately perceived by adult raters, especially when produced by CI users. This suggests a protracted development of the phonetic implementation of codas, where CI users, in particular, may benefit from targeted intervention.