No abstract

The purpose of this experiment was to determine whether age-related differences would be observed for discrimination of synthesized, 5-formant consonant-vowel syllables that differed in voicing onset time (VOT) of the initial consonant. Just noticeable differences (JNDs) were measured relative to the end points of the stimulus continuum, using a "same"-"different," adaptive procedure with trial-by-trial feedback/reinforcement and "catch" trials, in which members of the stimulus pair were identical syllables. 6-8-year-old children required significantly longer VOTs for syllabic discrimination than did adults. Adults' JNDs relative to [pa] at the end of the stimulus continuum with longer VOTs were significantly larger than their JNDs relative to [ba], as would be expected on the basis of psychoacoustic considerations, but neither 6-8-nor 8-11-year-old children showed this trend. Performance on "catch" trials for both groups of children was significantly poorer than for adults. Outcomes corresponded to results of other investigations that have reported that children require more acoustic information than adults to achieve the same performance criterion.

The purpose of this experiment was to determine whether age-related differences would be observed for discrimination of synthesized, 5-formant consonant-vowel syllables that differed in voicing onset time (VOT) of the initial consonant. Just noticeable differences (JNDs) were measured relative to the end points of the stimulus continuum, using a "same"-"different," adaptive procedure with trial-by-trial feedback/reinforcement and "catch" trials, in which members of the stimulus pair were identical syllables. 6-8-year-old children required significantly longer VOTs for syllabic discrimination than did adults. Adults' JNDs relative to [pa] at the end of the stimulus continuum with longer VOTs were significantly larger than their JNDs relative to [ba], as would be expected on the basis of psychoacoustic considerations, but neither 6-8-nor 8-11-year-old children showed this trend. Performance on "catch" trials for both groups of children was significantly poorer than for adults. Outcomes corresponded to results of other investigations that have reported that children require more acoustic information than adults to achieve the same performance criterion.

Previous research has shown that developing second language (L2) academic writers use a limited set of reporting verbs in comparison to more advanced writers (

Adaptive test procedures were employed in a field study to determine just-noticeable differences relative to each endpoint of an eight-item, /ba/pa/ continuum of five-formant, synthesized syllables that differed in 5-ms VOT steps. Difference limens for young adults were smaller than for 8–10 year-old children, for whom jnds, in turn, were smaller than for 6–7 year-old children. Difference limens at the /pa/ end of the continuum were larger than those for /ba/, for each age level. These age-related differences in VOT discrimination, in the presence of essentially 100% correct performance for all Ss on a clinical test of word discrimination, resemble previously reported age-related differences in discrimination of the place of articulation feature [L. L. Elliott et al., J. Acoust. Soc. Am. 70, 669–667 (1981)]. Performance of normally hearing, learning-disabled children will also be discussed. [Work supported, in part, by NINCDS.]