Figure 1.

Spectrograms of excerpts from adult female laughing (top) and infant female laughing (bottom), with a total duration of 2,820 ms for each adult and 3,379 ms for each infant laughing. The first row shows waveforms of natural laughing (left) and time‐reversed or fragment‐recombined laughing (right). Oscillograms and sonograms for the sound selections outlined in the first rows (rectangles) are shown in the second rows. They have durations of 673 ms for the adult and 774 ms for the infant stimulus.