2013 Theses Doctoral

Children's Perception of Conversational and Clear American-English Vowels in Noise

Leone, Dorothy

A handful of studies have examined children's perception of clear speech in the presence of background noise. Although accurate vowel perception is important for listeners' comprehension, no study has focused on whether vowels uttered in clear speech aid intelligibility for children listeners. In the present study, American-English (AE) speaking children repeated the AE vowels /ε, æ, ɑ, ʌ/ in the nonsense word /gəbVpə/ in phrases produced in conversational and clear speech by two female AE-speaking adults. The recordings of the adults' speech were presented at a signal-to-noise ratio (SNR) of -6 dB to 15 AE-speaking children (ages 5.0-8.5) in an examination of whether the accuracy of AE school-age children's vowel identification in noise is more accurate when utterances are produced in clear speech than in conversational speech. Effects of the particular vowel uttered and talker effects were also examined. Clear speech vowels were repeated significantly more accurately (87%) than conversational speech vowels (59%), suggesting that clear speech aids children's vowel identification. Results varied as a function of the talker and particular vowel uttered. Child listeners repeated one talker's vowels more accurately than the other's and front vowels more accurately than central and back vowels. The findings support the use of clear speech for enhancing adult-to-child communication in AE, particularly in noisy environments.