The use of tonal coarticulation in segmentation of artificial language speech: A study with Mandarin listeners

Tonal carryover assimilation, whereby a tone is assimilated to the preceding one, is conditioned by prosodic boundaries in a way suggesting that its presence may signal continuity or lack of a boundary. Its possibility as a speech segmentation cue was investigated in two artificial language (AL) learning experiments. Mandarin-speaking listeners identified the “words” of a three-tone AL (e.g., [pé.tī.kù]) after listening to six long speech streams in which the words were repeated continuously without pauses. The first experiment revealed that segmentation was disrupted in an “incongruent-cues” condition where tonal carryover assimilation occurred across AL word boundaries and conflicted with statistical regularities in the speech streams. Segmentation was neither facilitated nor inhibited in a “congruent-cues” condition where tonal carryover assimilation occurred only within the AL words in 27% of the repetitions and never across word boundaries. A null effect was again found for the congruent-cues condition of the second experiment, where all AL word repetitions carried tonal carryover assimilation. These findings show that tonal carryover assimilation is exploited to resolve segmentation problems when cues conflict. Its null effect in the congruent-cues conditions might be linked to cue redundancy and suggest that it is weighted low in the segmentation cue hierarchy.

Density, frequency and the expressive phonology of children with phonological delay

ABSTRACTThe effect of word-level variables on expressive phonology has not been widely studied, although the properties of words likely bear on the emergence of sound structure (Stoel-Gammon, 2011). Eight preschoolers, diagnosed with phonological delay, were assigned to treatment to experimentally induce gains in expressive phonology. Erred sounds were taught using stimulus words that varied orthogonally in neighborhood density and word frequency as the independent variables. Generalization was the dependent variable, defined as production accuracy of treated and untreated (erred) sounds. Blocked comparisons showed that dense neighborhoods triggered greater generalization, but frequency did not have a clear differential effect. Orthogonal comparisons revealed graded effects, with frequent words from dense neighborhoods being optimal for generalization. The results contrast with prior literature, which has reported a sparse neighborhood advantage for children with phonological delay. There is a suggestion that children with phonological delay require greater than usual cue redundancy and convergence to prompt expressive phonological learning.

Talking about comparisons: a study of young children's comparative adjective usage

ABSTRACTThis study explores factors other than the concept of comparison which influence the learning of specific comparative adjective forms, namely, (a) the nature of the perceptual input, and (b) the nature of the event. Thirty subjects, age 4; 5 to 7; 9, were asked to describe objects reflecting various attribute differences in both multiple-object comparison and single-object, dynamic-change tasks. Children used comparative adjectives to talk about dynamic changes prior to static comparisons, and attributes based on visual or tactile input were easier than those based on both. These results are interpreted as indicating that perceptual cue redundancy and heterogeneity affects the learning of attribute dimensions, and that children first use the -er suffix in a non-comparative sense.