Adults' Perception of Children's Vowel Production.

The study examined the link between Korean-speaking children's vowel production and its perception by inexperienced adults and also observed whether ongoing vowel changes in mid-back vowels affect adults' perceptions when the vowels are produced by children. This study analyzed vowels in monosyllabic words produced by 20 children, ranging from 2 to 6 years old, with a focus on gender distinction, and used them as perceptual stimuli for word perception by 20 inexperienced adult listeners. Acoustic analyses indicated that F0 was not a reliable cue for distinguishing gender, but the first two formants served as reliable cues for gender distinction. The results confirmed that the spacing of the two low formants is linguistically and para-linguistically important in identifying vowel types and gender. However, a pair of non-low back vowels caused difficulties in correct vowel identification. Proximal distance between the vowels could be interpreted to result in the highest mismatch between children's production and adults' perception of the two non-low back vowels in the Korean language. We attribute the source of the highest mismatch of the two non-low back vowels to the ongoing sound change observed in high and mid-back vowels in adult speech. The ongoing vowel change is also observed in the children's vowel space, which may well be shaped after the caregivers whose non-low back vowels are close to each other.