Discrimination and identification of synthetic speech by a child exhibiting voicing confusions in production

Abstract

Tests of speech sound identification and discrimination were administered to a 512-year-old boy who substituted voiced for voiceless initial stops and /d/ for initial fricatives. Stimuli were taken from the Abramson-Lisker VOT series for bilabial, alveolar, and velar stops. Discrimination (as measured by a verbal “same”-“not the same” task) was well above chance for pairs of speech sounds which spanned the typically found voicing boundary for adult listeners. Identification (as measured by a previously trained picture-pointing task) was, however, random. Normal controls were near ceiling on both tasks. Three months later, following considerable improvement in the child's production of initial voiceless stops, identification tests were repeated. The child's identification had improved only to a level of approximately 65% correct. Possible reasons for the discrepancy between the child's levels of performance on the two types of tasks are discussed. [Work supported by NIH.]