A percepção das fricativas coronais não vozeadas por crianças e adultos falantes nativos do português brasileiros: em busca de evidências para uma mudança evolutiva nos esquemas perceptuais

Abstract

Objective: to verify if children and adults attribute the same weight to the cues of frequency height of the fricative noise and transition of the second vowel formant or F2 transition to classify the minimal pair /aaR/-/asaR/ and the /u/-/su/ contrast. Methodology: the sampling for this study was constituted of children of ages four and seven years old, as well as adults. Ten subjects were tested in each of the three age groups. Both children and adults were recruited from two education centers in Belo Horizonte, MG. In order to gather the data for this study, two continuums were produced for /aaR/-/asaR/ and /u/- /su/, each. The acoustic cues manipulated were frequency height of the fricative noise and F2 transition. The cue that varied in an identical fashion in the two continuums was the frequency height of the fricative noise, which was modified from an appropriated frequency of [] (3360Hz) to an appropriated frequency of [s] (6240Hz) in nine uniform steps of 320Hz. The second cue was the F2 transition, which follows the fricative sound. The two forms were: a continuum with appropriated transition to follow [] and a continuum with appropriated transition to follow [s]. The participants performed a classification task in which they heard the stimuli on headphones and decided which category was the most coherent to what had been presented among the existing possibilities (/aaR/-/asaR/ and /u/-/su/). Results: the data gathered was statistically analyzed by the probit model. The results revealed that for the minimal pair /aaR/-/asaR/, in spite of the four-year-old children being able to very significantly weighting the cue of frequency height of the fricative noise, they attributed the largest weight to the cue of F2 transition when compared with the other age groups. The adult subjects attributed larger weight to the of frequency height of the fricative noise than the children of four and seven years old. As for the /u/-/su/ contrast, the adult was the only age group that presented only one tendency to use the cue of F2 transition to classify this contrast. All the age groups tested very significantly weighting the cue of frequency height of the fricative noise. Conclusions: the results showed that children of four attributed larger weight to the cue of F2 transition than those of seven years old or the adults to classify the minimal pair /aaR/-/asaR/. However, the first age group weighting more strongly the cue of frequency height of the fricative noise when compared to the cue of F2 transition. Regarding the /u/-/su/ contrast, the only age group which presented only one tendency to use the cue of F2 transition was the adult group. Hence, the classification results in this study suggested that the cue of frequency height of the fricative noise is more informative to the choice of articulation point in Brazilian Portuguese fricative sounds than the cue of F2 transition.