Trading relations in the perception of /r/‐/l/ by articulation‐delayed children

Abstract

Articulation‐delayed children who did not produce /r/ correctly and who showed slow progress in therapy, were tested on identification of two synthetic series contrasting prevocalic /r/ and /l/ in a trading relations paradigm. The primary spectral cue (F3 and F2 onset and transition) was varied in ten steps in both series. For one series, the secondary temporal cue (F 1 steady‐state and transition duration) was /r/‐like; in the other, it was /l/‐like. Result showed that phoneme boundaries along the spectral dimensions shifted appropriately as a function of the temporal cue value (i.e., a trading relation was demonstrated). However, the shift was somewhat smaller than for adults, and both boundaries were displaced toward the /l/ end of the spectral dimension, relative to the adults. These results suggest that such children have particular difficulty with the perceptual differentiation of spectral information, as might be predicted from their articulatory substitution patterns. [Supported by NIMH, NINCDS.]