A prosody modification system for use in text-to-speech includes an input receiving a sequence of prosodic data vectors Pn, measured at time Tn, which samples a sound waveform. A prosody data warping module directly derives new prosodic data vectors Qn from the original data vectors Pn using a function, which is controlled by warping parameters A0, . . . Ak, which avoids round-off errors in deriving quantized values, which has derivatives with respect to A0, . . . Ak, Pn, and Tn that are continuous, and which has sufficiently high complexity to model intentional prosody of the sound waveform, and sufficiently low complexity to avoid modeling micro-prosody of the sound waveform. The smoothness and simplicity of the function ensure that micro-prosodic perturbations and errors in measurement of Tn are transferred directly to the output Qn. The errors are thus reversed during re-synthesis and therefore eliminated, resulting in micro-prosodic perturbations being preserved during re-synthesis.