F0 stylization in speech : straight lines versus parabolas

This is a brief report on an experiment, intended to show that a piecewise linear approximation of an F0 curve in speech is, perceptually, not inferior to an approximation by means of fragments of parabolas, which gives-visually at least-a better fit to the original F0 curve than does the rectilinear approximation. (More details can be read in IPO Rep. no. 816, available on request). Stimuli consisted of two pairs of linearly or parabolically frequency modulated pulse trains, one of which contained identical, the other different members. The subjects had to indicate whether it was the first, or the second pair that contained different members. The results showed that even the best performers were hardly ever able to distinguish the parabolic from the rectilinear shapes, provided the latter contained a flattened peak.