The Pitch Contours Of Babbling Adapting To The Target Language

The present .study explores the properties of pitch contours in the early vocalizations of two Changsha infants, with an aim to ascertaining the degree of continuity between babbling and early words for children acquiring tonal languages as their first language. The paper was conducted by means of acoustic and statistic analysis from three aspects: the phonetic characteristics of the two infants from 8 months to 1 year and 3 months; comparison of various pitch contour types at the babbling stage and the babbling-words stage; and comparison of the pitch contour repertoire of babbling and that of early words.The study examined a male infant LSY, growing up in Changsha and exposed to Xiang dialects and Putonghua, and a female infant AJR, growing up in Changsha and exposed to Xiang dialects, a little English and Putonghua. Data from the first child covered the age range from 8 months to 1 year 3 months with 10 hours of audio recordings, including 1848 utterances, in which 2484 syllables were analyzed. Data from the second child ranged from 9 months to 1 year 3 months with 15 hours of recordings, consisting of 2407 utterances, in which 6143 syllables were analyzed. The pitch contours of each syllable were measured and analyzed by PRAAT, with 11 F0 values chosen for each continuous contour at equally spaced intervals. All the F0 values were involved in Lz-score processing within each session domain. The Lz-score value of each syllable was then converted to a relative pitch level description on a five-point scale, borrowing from the methods of Shi(1990) and Zhu(2004).The results show that: 1. the pitch contours with babbling and early words involved show the dispreferences for the lower end of the pitch scale or complex pitch contours in infant speech; 2. the pitch contours display the similarities between the babbling stage and the babbling-words stage; 3. the pitch contours demonstrate resemblances for babbling and early words.The conclusion can be drawn in view of the results. The similarities between the phonetic characteristics of pitch contours of the two Changsha infants, dispreferences for the lower end of the pitch scale or complex pitch contours in infant speech, reflect that infant productions have universal articulatory tendencies. The similarities between the pitch contours of babbling and early words, and the resemblances of various pitch contour types at the babbling stage and the babbling-words stage suggest the close relationship of babbling and early words. On the other hand, the divergence of relativepitch levels between the Changsha infant and Hong Kong infant(Lee, Lee and Chen 2005), the similarities of the pitch level in terms of mean pitch level, mean beginning level of falling and rising contours and mean terminal level of falling and rising contours for the two Changsha infants suggest the influence of linguistic environment. The similarities and divergences above suggest that the pitch contours of infants at the babbling stage are an interaction between the universal articulatory tendencies and the influence of the target language. Our phonetic analysis of the pitch of infants' vocalizations has shed light on the tendencies of the phonetic mechanisms involved in the acquisition of tone.