Illustration of “prototypical” acoustic features associated with utterances measured at their emotion identification point.

Each period of the sine wave represents the average duration of a syllable when produced to express each emotion, which are shown up to the average emotion identification point for the corresponding emotion. The horizontal line refers to the (normalized) f0Mean of utterances, and the waveform amplitude (shaded region) refers to the f0Range, at the corresponding emotion recognition point.