Phonological Specificity of Vowels and Consonants in Early Lexical Representations

Phonological Specificity of Vowels and Consonants in Early Lexical Representations

Nivedita Mani *, Kim Plunkett

Reviewed by IFTI LUTHVIANA DEWI

This research investigated infants’ sensitivity to vowels in lexical representations. There are two experiments, the first examines whether infants at 15, 18 and 24 months are sensitive to mispronunciations of vowels in familiar words. The second compares 15, 18 and 24-month-olds’ sensitivity to consonant and vowel mispronunciations of familiar words.

The participants in this experiment were 28 infants at 15 months, 30 infants at 18 months and 31 infants at 24 months. The stimuli presented to infants at 18 and 24 months were 16 monosyllabic (CVC) nouns taken from the OCDI. Each infant heard eight labels, were correctly pronounced while the other half were incorrectly pronounced. While, Infants at 15 months were tested on a slightly different set of 10 monosyllabic (CVC) words.

This study found that Infants become selectively sensitive to phonological distinctions relevant to their native language at an early age.

Early lexical representations of familiar words contain suitable information for very young English infants to detect mispronunciations. The results from the three age groups (15, 18 and 24 months) tested indicate that this vowel sensitivity is in place by 15-months-old. These findings also found the first experimental evidence that vowel identity makes lexical access for a wide range of monosyllabic, familiar words at an early stage of lexical development.

The findings eliminate the possibility that consonants play a more essential role than vowels in lexical processing in infancy, at least in recognition of familiar words at 18 months of age. Both consonants and vowels limit lexical recognition equally in the last half of the second year of life.

The role of vowels in lexical recognition in infancy:

·       The importance of vowels in lexical representation are depending upon additional empirical validation of the strength of vowel mispronunciation effects in the recognition of novel and familiar words, and mono- and bisyllabic words.

·       Exploration of cross-linguistic factors influence the understanding of the role of vowels in lexical access.

Infants were sensitive  to changes to the vowels of the words presented to them. Yet, there are likely to be vowel–consonant co-articulation effects that might lead to significant differences in the acoustic characteristics of the consonant between the correctly pronounced and mispronounced words.

Infant performance might have been triggered by the acoustic differences in the co-articulated consonants between the correct and incorrect pronunciations rather than because of the changes to the vowels themselves.

On this interpretation of the results, sensitivity to mispronunciations would be led by differences in the acoustic characteristics of the consonant and not the vowel. While this suggests a less essential role for vowels in lexical representation, there is no empirical evidence suggesting that infants’ performance is dependent on the acoustic characteristics of the co-articulated consonant alone.