A COMBINATION OF VOCAL F(O) DYNAMIC AND SUMMARY FEATURES DISCRIMINATES BETWEEN 3 PRAGMATIC CATEGORIES OF INFANT-DIRECTED SPEECH

To assess the relative contribution of dynamic and summary features of vocal fundamental frequency f(o) to the statistical discrimination of pragmatic categories in infant-directed speech, 49 mothers were instr ucted to use their voice to get their 4-month-old baby's attention, sh ow approval, and provide comfort. Vocal f(o) from 621 tokens was extra cted using a Computerized Speech Laboratory and custom software. Dynam ic features were measured with convergent methods (visual judgment and quantitative modeling of f(o) contour shape). Summary features were f (o) mean, standard deviation, and duration. Dynamic and summary featur es both individually and in combination statistically discriminated be tween each of the pragmatic categories. Classification rates were 69% and 62% in initial and cross-validation DFAs, respectively.